Friedrich Kuhl R 410A Users Manual RAC Standard Chassis IO_(06 12 10)_CS3

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2015-02-02

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Service Manual

Room Air Conditioners

AUTO
AUTO
CONTINUOUS

°F °C

AUTO

SYSTEM

FAN MODE

SCHEDULE

FAN SPEED

Standard Chassis R-410A Models
Cool Only
115-Volt: SS08M10, SS10M10, SS12M10, SS14M10
208-230-Volt: SS12M30, SS15M30, SM18M30, SM21M30
SM24M30, SL28M30, SL36M30
Cool with Electric Heat
208-230-Volt: ES12M33, ES15M33, EM18M34, EM24M35, EL36M35
Heat Pump with Electric Heat
208-230-Volt: YS12M33, YM18M34, YL24M35
Heat Pump
115-Volt: YS10M10
Kuhl-ServMan (5-10)

Table Of Contents
Important Safety Information ..................................................................................................................................... 2-4
Introduction ................................................................................................................................................................... 5
Model and Serial Number Location .............................................................................................................................. 5
Unit Identification .......................................................................................................................................................... 6
Performance Data and Specifications .......................................................................................................................... 7
Installation Information/Sleeve Dimensions/Circuit Rating ........................................................................................... 8
Electrical Data ............................................................................................................................................................... 9
Before Operating the Unit ............................................................................................................................................10
Control Panel Operation ..............................................................................................................................................11
Alerts ......................................................................................................................................................................12-14
Remote Control Operation ......................................................................................................................................15-16
Electronic Control System Maintenance Operation .................................................................................................17-20
Unit Operation .............................................................................................................................................................. 21
Cool-Heat Set Points .................................................................................................................................................. 22
Electronic Control Sequence of Operation ............................................................................................................ 23-29
Unit Operation with a Wall-Stat ................................................................................................................................... 29
Removing the Front Cover and Unit Chassis ................................................................................................................ 30
Replacing the ID Coil Thermistor ................................................................................................................................ 31
Replacing the Control Board ....................................................................................................................................... 31
Low Voltage Interface Connector ................................................................................................................................ 32
Replacing the ID Coil Thermistor ................................................................................................................................ 31
Remote Wall Thermostat ....................................................................................................................................... 32-33
Airflow Selection and Adjustment ............................................................................................................................... 33
Components Testing .............................................................................................................................................. 34-35
Refrigeration Sequence of Operation .................................................................................................................... 36-37
Sealed Refrigeration System Repairs ................................................................................................................... 38-41
Hermetics Components Check ................................................................................................................................... 42
Reversing Valve Description/Operation ...................................................................................................................... 43
Testing the Coil ........................................................................................................................................................... 44
Checking the Reversing Valve ............................................................................................................................... 44-45
Compressor Checks .............................................................................................................................................. 46-47
Compressor Replacement ..................................................................................................................................... 48-49
Routine Maintenance / Battery Check / Change ...................................................................................................... 50-53
Service and Assistance ............................................................................................................................................... 54
Performance Test Data Sheet and Sizing Guide .......................................................................................................... 55
Error Codes and Alarm Status .................................................................................................................................... 56
Troubleshooting ..................................................................................................................................................... 57-66
Electronic Control Board Components Identification ................................................................................................... 67
Wiring Diagrams .................................................................................................................................................... 68-75
Thermistors' Resistance Values .................................................................................................................................. 76
Remote Control Replacement Instructions ........................................................................................................... 77-78
User Interface Service Kit ........................................................................................................................................... 79
Instructions for Using Cooling Load Estimate Form ................................................................................................... 80
Cooling Load Estimate Form ...................................................................................................................................... 81
Heat Load Form .................................................................................................................................................... 82-83
Warranty ..................................................................................................................................................................... 84
1

IMPORTANT SAFETY INFORMATION
The information contained in this manual is intended for use by a qualified service technician who is familiar
with the safety procedures required for installation and repair, and who is equipped with the proper tools
and test instruments required to service this product.
Installation or repairs made by unqualified persons can result in subjecting the unqualified person making
such repairs as well as the persons being served by the equipment to hazards resulting in injury or
electrical shock which can be serious or even fatal.
Safety warnings have been placed throughout this manual to alert you to potential hazards that may be
encountered. If you install or perform service on equipment, it is your responsibility to read and obey these
warnings to guard against any bodily injury or property damage which may result to you or others.

Your safety and the safety of others are very important.
We have provided many important safety messages in this manual and on your appliance. Always read
and obey all safety messages.
This is a Safety Alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol with the word “WARNING”
or “CAUTION”. These words mean:

WARNING

You can be killed or seriously injured if you do not follow instructions.

CAUTION

You can receive minor or moderate injury if you do not follow instructions.

All safety messages will tell you what the potential hazard is, tell you how to reduce the chance of injury,
and tell you what will happen if the instructions are not followed.

NOTICE

A message to alert you of potential property damage will have the
word “NOTICE”. Potential property damage can occur if instructions
are not followed.

PERSONAL INJURY OR DEATH HAZARDS
ELECTRICAL HAZARDS:

•

Unplug and/or disconnect all electrical power to the unit before performing inspections,
maintenance, or service.

•

Make sure to follow proper lockout/tag out procedures.

•

Always work in the company of a qualified assistant if possible.

•

Capacitors, even when disconnected from the electrical power source, retain an electrical charge
potential capable of causing electric shock or electrocution.

•

Handle, discharge, and test capacitors according to safe, established, standards, and approved
procedures.

•

Extreme care, proper judgment, and safety procedures must be exercised if it becomes necessary
to test or troubleshoot equipment with the power on to the unit.

•

Do not spray or pour water on the return air grille, discharge air grille, evaporator coil, control panel,
and sleeve on the room side of the air conditioning unit while cleaning.

•

Electrical component malfunction caused by water could result in electric shock or other electrically
unsafe conditions when the power is restored and the unit is turned on, even after the exterior is dry.

•

Never operate the A/C unit with wet hands.

•

Use air conditioner on a single dedicated circuit within the specified amperage rating.

•

Use on a properly grounded outlet only.

•

Do not remove ground prong of plug.

•

Do not cut or modify the power supply cord.

•

Do not use extension cords with the unit.

•

Follow all safety precautions and use proper and adequate protective safety aids such as: gloves,
goggles, clothing, adequately insulated tools, and testing equipment etc.

•

Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.

REFRIGERATION SYSTEM REPAIR HAZARDS:
•

Use approved standard refrigerant recovering procedures and equipment to relieve pressure before
opening system for repair.

•

Do not allow liquid refrigerant to contact skin. Direct contact with liquid refrigerant can result in minor
to moderate injury.

•

Be extremely careful when using an oxy-acetylene torch. Direct contact with the torch’s flame or hot
surfaces can cause serious burns.

•

Make sure to protect personal and surrounding property with fire proof materials.

•

Have a fire extinguisher at hand while using a torch.

•

Provide adequate ventilation to vent off toxic fumes, and work with a qualified assistant whenever
possible.

•

Always use a pressure regulator when using dry nitrogen to test the sealed refrigeration system for
leaks, flushing etc.

•

Make sure to follow all safety precautions and to use proper protective safety aids such as: gloves,
safety glasses, clothing etc.

•

Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.

MECHANICAL HAZARDS:
•

Extreme care, proper judgment and all safety procedures must be followed when testing,
troubleshooting, handling, or working around unit with moving and/or rotating parts.

•

Be careful when, handling and working around exposed edges and corners of the sleeve, chassis,
and other unit components especially the sharp fins of the indoor and outdoor coils.

•

Use proper and adequate protective aids such as: gloves, clothing, safety glasses etc.

•

Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.

PROPERTY DAMAGE HAZARDS
FIRE DAMAGE HAZARDS:
•

Read the Installation/Operation Manual for the air conditioning unit prior to operating.

•

Use air conditioner on a single dedicated circuit within the specified amperage rating.

•

Connect to a properly grounded outlet only.

•

Do not remove ground prong of plug.

•

Do not cut or modify the power supply cord.

•

Do not use extension cords with the unit.

•

Be extremely careful when using acetylene torch and protect surrounding property.

•

Failure to follow these instructions can result in fire and minor to serious property damage.

WATER DAMAGE HAZARDS:

•

Improper installation, maintenance or servicing of the air conditioner unit can result in water damage
to personal items or property.

•

Insure that the unit has a sufficient pitch to the outside to allow water to drain from the unit.

•

Do not drill holes in the bottom of the drain pan or the underside of the unit.

•

Failure to follow these instructions can result in damage to the unit and/or minor to serious property
damage.

INTRODUCTION
This service manual is designed to be used in conjunction with the installation and operation manuals provided with
each air conditioning system.
This service manual was written to assist the professional RAC (Room Air Conditioner) service technician to quickly
and accurately diagnose and repair malfunctions.
This manual will deal with subjects in a general nature.

Accumulator
Compressor
Fresh Air Vent

Outdoor Grille
Discharge Air

Reversing Valve
Evaporator Coil
Condenser Coil

Electronic Control
Board

Sleeve

Control Key Pad
Support Bar

Air Intake Vents

Blower Wheel

Fan Blade
Fan/Blower Motor
Base Pan

Air Intake From
Sides and Bottom
Control Key Pad
(User Interface)

Chassis Pull
Out Handle

IMPORTANT: It will be necessary for you to accurately identify the unit you are servicing, so you can be certain of a
proper diagnosis and repair (See Unit Identification code on page 6).

MODEL AND SERIAL NUMBER LOCATION
Register the air conditioner
Model information can be found on the
name plate behind the front cover.
For your future convenience, record
the model information here.
MODEL NUMBER
MODEL NUMBER
AIR CONDITIONING CO. YS10M10A
SAN ANTONIO, TEXAS SERIAL NUMBER
ASSEMBLED IN MEXICO LICY00008

VOLTS 115
60 HZ / 1 PH
VOLTS MIN 108

COOLING
HEATING
BTH/HR 6500 BTH/HR 6500
EER 12.0
EER 10.4
AMPS 8.0
AMPS 7.0

REFRIGERANT XXXXXXXXX
30.1 OZ R410A 600 PSIG HS
300 PSIG LS

XXXXXXXXXX
XXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX

FUSE PROTECTED
CIRCUITS USE 15A
TIME DELAY FUSE

X
XX
XXXXX
XXXXXXXXXX

SERIAL NUMBER
MODEL NUMBER
AIR CONDITIONING CO. YS10M10A
SAN ANTONIO, TEXAS SERIAL NUMBER
ASSEMBLED IN MEXICO LICY00008

PURCHASE DATE

UNIT IDENTIFICATION
Model Number Code

S S 08 M 1 0 A
8th Digit – Engineering
Major change

1st Digit – Function
S = Straight Cool, Value Series
Y = Heat Pump
E = Electric Heat

7th Digit – Options
0 = Straight Cool &
Heat Pump Models
3 = 3 KW Heat Strip, Nominal
4 = 4 KW Heat Strip, Nominal
5 = 5 KW Heat Strip, Nominal

2nd Digit
S = Small Chassis
M = Medium Chassis
L = Large Chassis

6th Digit – Voltage
1 = 115 Volts
3 = 230-208 Volts

3rd and 4th Digit - Approximate
BTU/HR in 1000s (Cooling)
Heating BTU/Hr capacity listed in the
Specification/Performance Data Section

5th Digit
Alphabetical Modifier

RAC Serial Number Identification Guide
Serial Number
Decade Manufactured
L=0
C=3
F=6
J=9
A=1
D=4
G=7
B=2
E=5
H=8
Year Manufactured
A=1
D=4
G=7
B=2
E=5
H=8
C=3
F=6
J=9

K=0

Month Manufactured
A=Jan D=Apr G=Jul K=Oct
B=Feb E=May H=Aug L=Nov
C=Mar F=Jun J=Sept M=Dec

00001
Production Run Number

Product Line
R = RAC

PERFORMANCE DATA
COOLING
PERFORMANCE
DATA*
SS08M10-A
SS10M10-A
SS12M10-A
SS14M10-A
YS10M10-A
SS12M30-A
ES12M33-A
YS12M33-A
SS15M30-A
ES15M33-A
SM18M30-A
EM18M34-A
YM18M34-A
SM21M30-A
SM24M30-A
EM24M34-A
YL24M34-A
SL28M30-A
SL36M30-A

EVAP. AIR TEMP. DEG.
CONDENSER
F
Temp. TEMP DEG. F
Discharge Air
Drop F.
53
27
115
52
28
119
50
30
118
49
31
121
56
24
114
49
31
116
51
29
115
49
31
116
53
27
121
53
27
121
54
26
122
54
26
122
50
30
118
48
32
124
46
34
129
46
34
129
56
24
121
47
33
126
51
29
129

Discharge Suction
Super Heat
Temp
Temp
157
150
163
170
150
158
158
167
171
171
160
160
168
170
179
179
176
181
188

62
65
60
56
64
62
62
65
62
62
62
62
60
55
55
55
62
58
56

SubCooling

12
15
12
10
12
13
13
16
14
14
9
9
15
10
12
12
18
12
12

31
28
23
22
14
21
18
21
28
28
31
31
24
28
34
34
25
26
31

OPERATING
PRESSURES
Suction Discharge
151
145
137
132
152
142
140
140
138
138
145
145
130
137
123
123
135
133
122

400
455
435
425
395
405
400
455
430
430
450
450
410
455
495
495
480
430
470

R-410A
REF.
Locked Rotor Charge in
OZ.
Amps
32.0
24.0
50.0
51.0
57.0
35.0
63.0
29.0
34.5
33.0
30.0
33.0
30.0
33.0
26.0
34.5
32.0
32.5
32.0
32.5
42.0
55.0
42.0
55.0
44.0
49.5
46.0
55.0
47.0
40.0
47.0
40.0
47.0
74.0
60.0
78.5
96.0
77.0

ELECTRICAL RATINGS
Amps
Cool
6.1
8.0
10.0
12.0
7.8
4.8
4.8
5.2
6.4
6.4
7.4
7.4
8.5
9.4
11.0
11.0
11.1
13.5
19.0

Amps
Heat

7.6
16.0
5.1
16.0
19.5
8.5

12.2

Voltage
115
115
115
115
115
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208v
230/208V
230/208v
230/208v

BREAKER
FUSE
60 Hertz
Amps
15
15
15
15
15
15
15
15
15
15
15
30
15
15
20
30
30
20
30

*Rating Conditions: 80 degrees F, room air temp. & 50% relative humidity, with 95 degree F, outside air temp & 40% relative humidity, all
systems use R-410A.

SPECIFICATIONS

ENERGY STAR® qualified
Energy Estimated
Efficiency
Yearly
Moisture
Ratio
Operating Removal
COP
EER
Cost
Pints/HR

Room Side
Air
Net
Circulation
Weight
CFM
Sleeve Lbs

Cooling
Capacity Btu

Heating
Capacity Btu

Volts
Rated

Cooling
Amps

Cooling
Watts

Heating
Amps

Heating
Watts

SS08M10

7900

—

115

6.1

677

—

11.7

$54

1.0

265

SS10M10

9500

—

115

7.7

848

—

11.2

$68

2.0

260

106

SS12M10

12000

—

115

10.0

1071

—

11.2

$86

3.0

300

112

SS14M10

14000

—

115

12.0

1444

—

9.7

$115

3.5

325

116

SS12M30

11700/11200

—

230/208

4.8/4.9

1026/982

—

11.4/11.4

$82

2.8

275

112

SS15M30

14500/14300

—

230/208

6.4/6.8

1405/1385

—

10.3/10.3

$112

3.5

360

116

SM18M30

17500/17200

—

230/208

7.4/8.0

1635/1617

—

10.7/10.7

$131

4.6

350

140

SM21M30

20800/20700

—

230/208

9.4/10.3

2080/2070

—

10.0/10.0

$166

6.0

425

132

Model

Kühl

SM24M30

23500/23300

—

230/208 11.2/11.9 2500/2479

—

9.4/9.4

$200

10.0

390

152

SL28M30

27800/27000

—

230/208 13.5/14.4 2865/2812

—

9.7/9.6

$229

8.5

600

193

SL36M30

36000/35700

—

230/208 19.0/20.5 4235/4200

—

8.5/8.5

$338

12.0

725

212

109

Kühl + Heat Pump
YS10M10*
9500
7500
115
YS12M33 12100/12100 9400/9000 230/208
YM18M34 18200/17800 15500/15400 230/208
YL24M35

7.8

812

7.6

743

3.0

11.7

$65

1.9

285

5.2/5.4

1120/1120

5.6/5.8

1132/1139

2.4

10.8/10.8

$89

3.0

265

115

8.5/8.9

1838/1798

8.5/8.7

1833/1761

2.6

9.9/9.9

$147

5.4

370

141

12.2/14.3 2610/2575

2.6

9.7/9.7

†

7.0

600

197

24000/23600 23500/23200 230/208 11.1/12.0 2474/2433

Kühl + Electric Heat
ES12M33

11700/11200

10700/8900 230/208

4.8/4.9

1026/982

16.0/14.7 3500/2900

3.3

11.4/11.4

$82

2.8

275

113

ES15M33

14500/14300

10700/8900 230/208

6.4/6.8

1405/1385

16.0/14.7 3500/2900

3.0

10.3/10.3

$112

3.5

360

117

EM18M34

17500/17200 13000/10600 230/208

7.4/8.0

1635/1617

19.5/17.0 4200/3500

3.1

10.7/10.7

$131

4.6

350

141

EM24M34

23500/23300 13000/10600 230/208 11.2/11.9 2500/2479

19.5/17.0 4200/3500

3.1

9.4/9.4

$200

10.0

390

153

EL36M35

36000/35700 17300/14300 230/208 19.0/20.5 4235/4200

24.0/22.4 5500/4650

2.5

8.5/8.5

$338

12.0

725

213

* Operates on 115 volt and is not equipped with supplemental heat. Will not provide heat at temperatures below 40°F.
Friedrich room air conditioners are designed to operate in outdoor temperatures from 60° F to 115° F.

R-410A

Due to continuing research in new energy-saving technology, specifications are subject to change without notice.
As an ENERGY STAR® partner, Friedrich Air Conditioning Co. has determined that the selected ENERGY STAR® () models meet the ENERGY
STAR® guidelines for energy efficiency.
The consumer- through the AHAM Room Air Conditioner Certification Program- can be certain that the AHAM Certification Seal accurately states
the unit’s cooling and heating capacity rating, the amperes and the energy efficiency ratio.

All models use
environmentally
friendly R-410A
refrigerant.

Estimated yearly operating cost based on a 2007 national average electricity cost of 10.65 cents per kWh.
† The estimated yearly operating cost of this model was not available at the time the range was published.

Installation Information / Sleeve Dimensions

Sleeve
S
M
L

Height
15

15/16 "

3/16"

Width
25

15/16 "

28"

Depth Shell Depth to Minimum
with Front
Louvers
Extension
Into Room*
29"

8 ¾"

5 ¾”

29"

8 ¾"

5 ¾”

35 ½”

16 ½"

Minimum
Extension
Outside*

3/8 ”

15/16 ”

Thru-the-wall Installation
Finished Hole

Window Width
Minimum** Maximum
27

3/8 "

7/8 ”

42"
42"
42"

Height

Width

3/16”

7 3/8"

3/16”

7 3/8 ”

3/8 "

28 ¼"

Max. Depth

15 1/8 ”

* Minimum extensions when mounted in a window.
** Minimum widths achieved using one side curtain assembly as opposed to both in a standard installation.
NOTE: S,M and L sleeves may be installed in window with no side kits if properly installed.

Circuit Rating/ Breaker
Model
SS08M10, SS10M10, SS12M10 and
SS14M10. YS10M10.

Circuit Rating
Breaker or
T-D Fuse

125V - 15A

(C)

Plug Face Power Cord
(NEMA#) Length (ft.)

5 - 15P

Wall Outlet
Appearance

Front
SS12M30, SS15M30, SM18M30 and
SM21M30.

250V - 15A

6 - 15P

SM24M30, SL28M30. ES12M33,
ES15M33. YS12M33

250V - 20A

6 - 20P

250V - 30A

6 - 30P

SL36M30. EM18M34, EM24M34,
EL36M35. YM18M34 and YL24M35

(B)

SIDE VIEW

For the best cooling performance and highest energy efficiency
Keep the filter clean

Make sure that your air conditioner is always in top performing condition
by cleaning the filter regularly.

Provide good air flow

Make sure the airflow to and from the unit is clear. Your air conditioner puts the
conditioned air out at the top of the unit, and takes in unconditioned air at the
bottom. Airflow is critical to good operation. It is just as important on the outside
of the building that the airflow around the unit exterior is not blocked.

Unit placement

If your air conditioner can be placed in a window or wall that is shaded by a tree
or another building, the unit will operate even more efficiently. Using drapes or
blinds on the sunny side of the dwelling will also add to your unit’s efficiency.

Insulation

Good insulation will be a big help in maintaining desirable comfort levels.
Doors should have weather stripping. Be sure to caulk around doors and
windows.

Proper installation of seal gasket

Make sure the seal gasket has been installed properly to minimize noise
and improve efficiency. If the seal gasket has not been installed, please
refer to the installation instructions.

ELECTRICAL DATA

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation.
All electrical connections and wiring MUST be
installed by a qualified electrician and conform to
the National Electrical Code and all local codes
which have jurisdiction.
Failure to do so can result in personal injury or
death.

NOTICE
FIRE HAZARD
Not following the above WARNING could result in fire or
electically unsafe conditions which could cause moderate
or serious property damage.
Read, understand and follow the above warning.

Wire Size

Use ONLY wiring size recommended for single outlet branch circuit.

Fuse/Circuit Breaker

Use ONLY the correct HACR type and size fuse/circuit breaker. Read electrical ratings on unit’s
rating plate. Proper circuit protection is the responsibiity of the homeowner.

Grounding

Unit MUST be grounded from branch circuit through service cord to unit, or through separate
ground wire provided on permanently connected units. Be sure that branch circuit or general
purpose outlet is grounded.

Receptacle

The field supplied outlet must match plug on service cord and be within reach of service cord.
Do NOT alter the service cord or plug. Do NOT use an extension cord. Refer to the table above
for proper receptacle and fuse type.

The consumer - through the AHAM Room Air Conditioner Certification Program - can
be certain that the AHAM Certification Seal accurately states the unit’s cooling and
heating capacity rating, the amperes and the energy efficiency ratio.
*HACR: Heating Air Conditioning and Refrigeration

WARNING: Before Operating Your Unit
WARNING
Electrical Shock Hazard
Make sure your electrical receptacle has the
same configuration as your air conditioner’s
plug. If different, consult a Licensed Electrician.
Do not use plug adapters.
Do not use an extension cord.
Do not remove ground prong.
Always plug into a grounded 3 prong oulet.
Failure to follow these instructions can result in
death, fire, or electrical shock.

Make sure the wiring is adequate for your unit.

NOTICE
Do not use the LCDI device as an ON/OFF switch.
Failure to adhere to this precaution may cause
premature equipment malfunction.
Once plugged in, the unit will operate normally without the need to reset
the LCDI device. If the LCDI device fails to trip when tested or if the power
supply cord is damaged, it must be replaced with a new power supply cord
from the manufacturer. Contact our Technical Assistance Line at (800)
541-6645. To expedite service, please have your model number available.
Table 1.

If you have fuses, they should be of the time delay type. Before you install
or relocate this unit, be sure that the amperage rating of the circuit breaker
or time delay fuse does not exceed the amp rating listed in Table 1.

CIRCUIT RATING
OR TIME DELAY
FUSE

MODEL

DO NOT use an extension cord.
The cord provided will carry the proper amount of electrical power to the
unit; an extension cord may not.

Make sure that the receptacle is compatible with
the air conditioner cord plug provided.
Proper grounding must be maintained at all times. Two prong receptacles
The grounded receptacle should meet all national and local codes and
ordinances. You must use the three prong plug furnished with the air
conditioner. Under no circumstances should you remove the ground
prong from the plug.

REQUIRED
WALL
RECEPTACLE

AMP

VOLT

NEMA
NO.

SS08M10, SS10M10,
SS12M10, SS14M10,
YS10M10

125

5-15R

SS12M30, SS15M30,
SM18M30, SM21M30

250

6-15R

SL25M30, SL28M30,
ES12M33, ES15M33,
YS12M33

250

6-20R

SL36M30, EM18M34,
EL25M35, EL36M35,
YM18M34, YL24M35

250

6-30R

Test the power cord
All Friedrich room air conditioners are shipped from the factory with a
Leakage Current Detection Interrupter (LCDI) equipped power cord. The
LCDI device on the end of the cord meets the UL and NEC requirements
for cord connected air conditioners.
To test your power supply cord:

Figure 1
TEST
RESET

TEST
RESET

WARNING

Press RESET (See Figure 1).

TEST BEFORE EACH USE
1. PRESS RESET BUTTON
2. PLUG LCDI INTO POWER
RECEPTACLE
3. PRESS TEST BUTTON,
RESET BUTTON SHOULD
POP UP

Press TEST, listen for click; the RESET button trips and pops out.

4. PRESS TEST BUTTON,
FOR USE
DO NOT USE IF ABOVE TEST
FAILS

Plug power supply cord into a grounded 3 prong outlet.

Press and release RESET (Listen for click; RESET button latches
and remains in). The power cord is ready for use.

WHEN GREEN LIGHT IS ON
IT IS WORKING PROPERLY

WARNING
TEST BEFORE EACH USE
1. PRESS RESET BUTTON
2. PLUG LCDI INTO POWER
RECEPTACLE
3. PRESS TEST BUTTON,
RESET BUTTON SHOULD
POP UP
4. PRESS TEST BUTTON,
FOR USE
DO NOT USE IF ABOVE TEST
FAILS
WHEN GREEN LIGHT IS ON
IT IS WORKING PROPERLY

15/20A LCDI Device

30A LCDI Device
FRR001

Control Panel Operation

FAN SPEED Button – Used to sequentially select bet ween fan speeds.
Depending on your model, you can select between LOW, MED, HIGH,
and MA X and AUTO. Max setting not available on SL and Kuhl+ models.
When the
button is pressed, the fan speed is temporarily displayed
in the display window, plus a fan speed icon (triangle) changes to indicate
the new speed level. When auto is selected, fan speed automatically varies
depending on the set temperature on the control panel and the actual
room temperature. Let me explain. Say for example you’re working in
your garage and you need to open the big door for several minutes. The
air conditioner will sense a wide difference between the set temperature
and the actual room temperature when this occurs the system fan speed
increases to MAX. The fan speed decreases (in step) as the temperature
difference decreases. When the set point temperature is reached the FAN
speed returns to the original setting.

Let’s check out how to control your air conditioner. On the control panel,
just to the left of the POWER , is a liquid crystal display (LCD). All of the
control panel function buttons and mode icons can be viewed in Figure 1.
Power On – Press the
button to turn on the air conditioner. The
power button will illuminate to indicate the power is on. The backlight on
the power switch will automatically dim to 20% intensity after 120 seconds
of inactivity. The remote control can also be used to turn power ON / OFF
(See Remote Control).
Display –
light. The back light has an automatic two (2) step dim function. After 120
seconds of inactivity, the display dims to 20% intensity. After an additional
120 seconds, the display switches off. Touching buttons will automatically
bring the display to full brightness.

SCHEDULE Button – The
button turns the schedule function on
and off. The current day of the week is indicated as a dot underneath
the day symbol. Pressing the
button a second time turns the
schedule function off. The schedule function comes preprogrammed with
recommended energy savings values (Addendum 1). The values may
be changed through the schedule program function (See Programmable
Thermostat).

There are four control push buttons on each side of the display.
SYSTEM Button – Allows the user to sequentially select,
Cool
, HEAT , and FAN ONLY operation. Press the
button and
the display advances to the next mode. A new icon appears. At the same
time, the mode displays for two (2) seconds, then returns the display to
the temperature set point for modes other than FAN. Note that on cool
only units, there are no HEAT and
modes.

UP and DOWN arrows – Pressing either
(UP) or
(DOWN) button
changes the desired room temperature. The factory preset lower and
upper limits are 63° F (16° C) and 99° F (37° C). These buttons are also
used to navigate between function options when using the User Menu or
Maintenance Mode.

FAN MODE Button – Selects between automatic
or
operation. In the
mode, the fan only turns on and off when the
compressor operates or the heat function is enabled.

BACK Button – This button is used af ter a menu item has been selected.
It takes the user back to the previous menu level and to save and exit.

In the SYSTEM FAN ONLY Mode,
is not available. In the
button.
mode, fans speed is determined by your selection on the

DISPLAY/ENTER Button – This button is used in conjunction with User
Menu and Maintenance Mode operation to select items. This button may
also be used to alternatively display the ROOM TEMPERATURE,
OUTDOOR TEMPERATURE, and TIME. If the display is left inactive for
10 seconds it will reset to the TEMPERATURE SET POINT.

Figure 1
AUTO
MODE

COOL
MODE

HEAT
MODE

SYSTEM

AU TO

FA N
MODE

AU TO

FA N
SPEED

AU TO

FAN
ONLY
MODE

MAINTENANCE
REQUIRED

FRONT
PANE L
LOCK

CHECK
FI LT ER
OUTDOOR TEMP
ROOM TEMP % RH

FILTER
MAINTENANCE

ON
OFF

WAIT

BACK

EXIT
RESET

HE AT -> SET POINT <- C OOL

CONTINUOUS

F
A
M
P
M

M T W T F S S

SCHEDULE

BUTTONS

WAKE

AW AY

R E T URN

NIGHT

DISPLAY

POWER

ENTER

SCHEDULE
ON/OFF

SCHEDULE
PERIODS

BUTTONS

ALERTS (The control system has five (5) customer alerts)
CHECK FILTER
appears on screen. The word “
” appears next to the
button.
The
alert is issued when the fan run time is greater than 500 hours.
This alert may be reset by the user (Refer to Special Functions, Filter Reset).
Maintenance Required – When maintenance is required, a service icon
appears on screen. This icon will not be dismissed until maintenance
has been performed. If the service icon
the icon

is on standby the system has sensed an abnormal condition.

is established the service icon

goes away.

Wait – The WAIT icon illuminates when the compressor lockout is active.
Whenever the compressor shuts off, system pressures must be allowed
to equalize. At this time, an internal timer begins a count-down from up to
240 seconds. If a demand for heat or cool occurs during this count-down
the WAIT icon
displays letting you know that the compressor will not
operate until the count-down has completed. This timer prevents damage
to the unit if it tries to start too quickly after it stops running. Normally the
WAIT icon
is off. Once the timer has cleared, the air conditioner will
heat or cool based on the temperature setting. Electric heat is not affected
by this timer.
Protection Alert (Freeze) – If the room freeze protection is active, the
display indicates this by showing Room Freeze Protection "FRZ". Once
temperature is less than 40° F (4° C), and the air conditioner is equipped with
electric heat, the room freeze protection will activate. The air conditioner
will run high fan and electric heat until the room temperature reaches
46° F (8° C). Pressing the
button delays the freeze protection function
Low Battery – When the battery is low a warning display
will be
inserted before other messages such as “COOL”. If the Low Battery
alert is on, the battery in the control unit must be changed. Refer
to the changing the battery procedure. Once the battery is changed, the
alert message will go off. Refer to Troubleshooting Tips. Under normal
conditions the battery life should be greater than 7 years.

Special Functions
Panel Lock
– The front panel push buttons can be locked to prevent
inadvertent operation. To lock the front panel, press and hold the
+
buttons for three (3) seconds. A double beep indicates your mode
change was successful and a
icon appears on the display. To unlock
the display, press and hold the
+
buttons for three (3) seconds.
The
icon will no longer be visible.
SCHEDULE

The hour digits flash first. The user presses the
or
to change the hours. To change AM-PM, the hours must be
advanced 12 hours. Press the
key to change to the
minutes. To exit the selection process, user presses the
key which will go to the time screen.

The minutes digits flash. The user presses the
or
to change the minutes. Press the
key to change the days.
To exit the selection process, the user presses the
key
which will go to the time screen.

The dot underneath the days of the week begins to blink to
indicate which day it is. If the user has not set the date before,
the dot starts on Monday. If the user is making a correction to
previously set information the dot appears under whichever
day the unit thinks it is. The user can press
or
to move
the dot left or right (respectively) along the week. The user
presses
to loop back to the hours setting. To exit the
selection process, the user presses the
key which will go
to the time screen.

Tuesday has been selected. The user presses
to loop
back to the hours setting. To exit the selection process and
accept the changes, the user presses the BACK key which will go
to the time screen.

Time Setting – When in the User Menu, on the Control Panel, use the
(UP) and
(DOWN) to select TIME. Push
, the hours segment
(UP) and
(DOWN) to set the hour, then push
(UP) and
(DOWN)
.
to set the minutes, then push

SCHEDULE

NOTE:

If the AM or PM indicator is incorrect, push
until the hours
(UP) or
(DOWN) to advance
the hour segment 12 hours, then push
. The day of the week
displays. Use the
(UP) or
(DOWN) to select the current
day. Press the
key to save and go back to the TIME screen.
(UP) to go to the next menu 1224.
Press

NOTE:

Pressing the
button again will exit the user menu function
mode. Or simply leave the control inactive for 15 minutes and
the control will return back to normal operation.

Filter Reset –
icon displays, the timer may be reset by pressing
and holding the
button for three (3) seconds. A beep indicates the
system timer was reset and the
icon and the word " RESE T " will
no longer be visible.
User Menu Functions – The User Menu Functions allows you to change
the following selections: Set TIME, 12/24 Hour Clock Format, BEEP ON /
OFF, DIM ON / OFF, Emergency Heat (EMHT) ON / OFF, Auto BAND Adjust,
F/ C Select, FRZ ON / OFF, Temp Offset (TO) and the Automatic Temperature
Sensing Feature (ATSF).
To enter the User Menu, press and hold
for 3 seconds, the TIME
selection appears. Use the
(UP) or
(DOWN) buttons to scroll
through the User Menu. Press the
button to enter the displayed
function. If left inactive for 15 minutes the User Menu display will no longer
be visible and it returns to normal operation mode display. To manually
exit the User Menu, press the
button.

SYSTEM

EXIT

BACK

FAN
MODE

SYSTEM

EXIT

BACK

FAN
MODE

FAN
SPEED

FAN
SPEED
DISPLAY

SCHEDULE

ENTER

DISPLAY

SCHEDULE

ENTER

User presses
or
to toggle the format between 12HR and
24HR display. To exit the selection process and accept the
change, press the
key.

User presses
or
to toggle between Emergency Heat On
and Emergency Heat Off. Press the
key to accept the
change and exit the selection process.

Clock Type – You may select between a 12 hr and 24 hr clock. When
1224 is displayed press the
key then press
(UP) or
(DOWN)
to toggle between 12 hr and 24 hr clock. To accept the change, press the
key to return to the 1224 screen. Press the
(UP) to go to the
next menu BEEP.

Emergency Heat – The Kühl+ heat pump models (YS, YM, YL) have
a special feature that is designed to keep the unit providing heat.
key then press
(UP) or
When EMHT is displayed press the
(DOWN) to toggle bet ween ON and OFF.

SYSTEM

EXIT

BACK

FAN
MODE

To accept the change, press the
key to return to the EMHT screen.
Press the
(UP) to go to the next menu BAND.
In the unlikely event of a compressor failure, the heat pump unit may be
switched to operate in the electric heat mode only until repairs can be
made.

FAN
SPEED
SYSTEM
SCHEDULE

User presses
or
Off. Press the
selection process.

EXIT

BACK

DISPLAY
ENTER

to toggle between Beep On and Beep
key to accept the change and exit the

FAN
MODE
FAN
SPEED
DISPLAY

SCHEDULE

ENTER

The menu allows the user to adjust the minimum spread
between the Auto Cool set point and the Auto Heat set point.
Press the
or
key to adjust. The adjust range is 3 to 10.

Audible Alerts – You can select to have the control beep when entering
key then press
(UP)
menus. When BEEP is displayed press the
or
(DOWN) to toggle between ON and OFF. To accept the change,
press the
key to return to the BEEP screen. Press the
(UP) to go
to the next menu EMHT on Kühl+ models or F C for Kühl models.

Auto Changeover ‘Dead Band’ – A buffer Zone between heating and
cooling in which no conditioning occurs. For Kühl+ models with the auto
changeover feature you can select the temperature band between heating
and cooling. From the factory the band is set at 3° F (-16° C). The band is
adjustable from 3° F (-16° C) to 10° F (-12° C). When BAND is displayed
press the
key then press
(UP) or
(DOWN) to toggle between
3 and 10. To accept the change, press the
key to return to the BAND
screen. Press the
(UP) to go to the next menu F C.

FAN
SPEED

SCHEDULE

DISPLAY
ENTER
SYSTEM

User presses
or
to select between AUTO, DM 20, OFF.
Press the
key to accept the change and exit the
selection process.

BACK

FAN
SPEED

SCHEDULE

The Dim Auto automatically dims the display to 20% and then
turns it off after a period of time. The Dim 20 setting behavior
is similar to AUTO, but prevents the display from turning off.
Minimum brightness is 20%. The Dim Off setting forces the
display to run at full brightness.

EXIT

FAN
MODE

DISPLAY
ENTER

User presses
or
at the same time to toggle between
Fahrenheit or Celsius as their temperature unit of choice.
Press the
key to accept the change and exit the selection
process.

Fahrenheit / Celsius Selection – You may select between displaying
temperature in F or C. When F C is displayed press the
key then
press
(UP) or
(DOWN) to toggle between F and C. To accept the
key to return to the F C screen. Press the
change, press the
(UP) to go to the next menu FRZ.

SYSTEM

BACK

EXIT

FAN
MODE

FAN
SPEED

SCHEDULE

DISPLAY

ENTER

User presses
or
to select between Freeze Protection On
& Freeze Protection Off. Press the
key to accept the
change and exit the selection process.

Freeze Protection – The Kühl+ models have a special feature that is
designed to keep the interior space above freezing by energizing the
electric heater anytime the indoor room temperature falls to 40° F (4° C).
With the freeze protection feature turned on, when the unit senses the
indoor temperature fall to 40° F (4° C) the unit will run the heater and high
fan until the space reaches 46° F (8° C) When FRZ is displayed press
the
key then press
(UP) or
(DOWN) to toggle between ON
and OFF. To accept the change, press the
key to return to the FRZ
screen. Press the
(UP) to go to the next menu TO.
SYSTEM

BACK

EXIT

FAN
MODE
FAN
SPEED

SCHEDULE

DISPLAY
ENTER

User presses
or
to select between ATSF On or Off.
Press the
key to accept the change and exit the
selection process.

Automatic Temperature Sampling Feature - The automatic temperature
sampling feature maintains a balanced temperature throughout the room
by circulating the air for 30 seconds once every 9 minutes that the unit is
not running when it is set to cooling or heating mode. By circulating the air
the unit can detect hot or cold areas in the room and operate the unit to
cool or warm the room as necessary. This function is only available when
the fan mode is set to ‘AUTO’ or in COOL or HEAT Mode. (Heating function
only available on Kuhl+ units)

User presses
or
to increment/decrement the temperature
offset (TO) for the room temperature sensor. (Maximum offset
= +/- 8 degrees F). Press the
key to accept the change
and exit the selection process

Temperature Offset – In some cases the built in thermostat on the unit
may not display the temperature as it is felt in the room. This can be caused
by many things including the size of the unit, the heat load on the room or
other factors. Friedrich allows you to select the appropriate temperature
offset to make the temperature readout as accurate as possible for your
application. In many cases the factory 0° F (-18° C) offset will provide
an accurate temperature readout. To change the offset follow these
instructions. When TO is displayed press the
key then press
(UP) or
(DOWN) to toggle between 0° F (-18° C) and 8° F (-13° C).
In most instances an offset from 0° F (-18° C) to 2° F (-17° C) is all that is
necessary. To accept the change, press the
key to return to the TO
screen. Press the
(UP) to go to the next menu ATSF.
You may cycle through the menus using the
to access any of the menus.

(UP) or

(DOWN) keys

For display only. No user selectable options.

Firmware Version - When VER is displayed press Display /
Enter key. The firmware version is displayed as left digit
(Major) and right digit (Minor). This version number should be
used along with Model and Serial numbers for service.

DIGITAL CONTROL PANEL'S ACCESS CODES SUMMARY

Key Sequence

Action

Filter Reset
Enter User Menu
Enter Maintenance Menu
Schedule ON/OFF
Enter & Exit Schedule Programming
Reset Error Codes & Error History
Lock Control Panel

Press BACK key for 3 sec + play double beep ()
PressDISPLAY/ENTER key for 3 sec + play double beep ()
Press SYSTEM + SCHEDULE + BACK + DISPLAY/ ENTER for 3 sec + play double beep ()
Press SCHEDULE once each time
Press SCHEDULE for 3 sec + play double beep ()
Press + for 3 sec + play double beep ()
Press SCHEDULE + DISPLAY/ENTER for 3 sec + play double beep ()

Remote Control Operation

FAN SPEED Button – Used to sequentially select new fan speed, plus
AUTO operation. When the
button is pressed, the fan speed is
temporarily displayed in the display window, plus a fan speed icon (triangle)
changes to indicate the new speed level. Fan speed automatically varies
depending on the set temperature on the control panel and the actual
room temperature. Let me explain. Say for example you’re working in
your garage and you need to open the big door for several minutes. Since
there is a big difference between your set temperature and the actual room
temperature the system fan speed increases to MAX. It remains at this
speed until the room temperature matches the set temperature.
FA N
SPEED

Remote Control – Refer to Figures 11 and 12 during operation description.
Getting Started – Install two (2) AAA batteries in the battery compartment
located on the back of the unit.
Operation – The remote control should be within 25 feet of the air
conditioner for operation (Refer to Figure 10 for effectiveness). Press the
button to turn the remote on. The remote will automatically power off
after 15 seconds if the buttons are not being pressed. The remote must
be on to control the unit.

SCHEDULE Button – The
button turns the schedule function on and
off. Pressing the
button a second time turns the schedule function
off. Only the schedule icon will be displayed.
SCHEDULE

POWER Button – Turns remote and unit on and off.

SCHEDULE

SYSTEM Button – Allows the user to sequentially select,
Cool ,
HEAT , and FAN ONLY operation. When the button is pressed, the
display indicates which mode has been selected via a display message.
Note that when the heating function is not available, the system will
automatically skip the HEAT and AUTO modes.

UP and DOWN Arrows – Pressing either the
(UP) or
(DOWN)
button changes the desired room temperature. The factory preset lower
and upper limits are 60° F (16° C) and 99° F (37° C). These buttons are
also used to navigate between function options when using the User Menu
or Maintenance Mode.

FAN MODE Button – Selects between automatic (
) or
operation. In the AUTO mode, the fan only turns on and off when the
compressor operates or the heat function is enabled.
NOTE:

Remote Effectiveness
Hand Held Remote – Has an operating range of up to 25 ft. The infrared
remote control signal must have a clear path to transmit the command to
the air conditioning unit. The remote signal has some ability to "bounce"
off of walls and furniture similar to a television remote control. The diagram
below shows the typical operating range of the control in a standard room
with 8 ft high ceilings.

AUTO is not available in the FAN ONLY Mode, the display
indicates
. In the
mode, fan speed is
determined by your selection on the
button.

TOP VIEW
25ft

25ft

7.5ft

SIDE VIEW

4ft
45°

60°

60°
6ft

30°

60°

8ft

45°

25ft
60°

30°

45°

30°

30°
16ft

8ft

25ft

Changing Temperature from F˚ (Fahrenheit) To C˚ (Celsius) or Reverse
Be within 25' of unit with the remote control. Press the SYSTEM and FAN MODE buttons at the same time and hold for 3
seconds. The display will show the temperature in Celcius. Do the same to reverse temperature to F˚ (Fahrenheit).

Remote Control Operation (Continued)
Figure 1
DISPLAY

SYSTEM

FAN MODE
POWER

TEMPERATURE
UP

TEMPERATURE
DOWN

FAN SPEED

SCHEDULE

FRR005

Figure 2
AUTO
ICON

COOL
ICON

HEAT
ICON

FAN ONLY
ICON

SYSTEM
MODE
°F / °C
ICONs
FAN
MODE

FAN
SPEED

SCHEDULE
ICON

2 X 16 SEGMENT
DISPLAY
FRR006

ELECTRONIC CONTROL SYSTEM MAINTENANCE
Introduction
This section contains information on the maintenance alerts, temperature limiting, diagnostic test and how to access. The electronic
control system has a built in maintenance sub system which works constantly behind the scenes to help identify problems with the air
conditioner or control system. When maintenance is required, a service icon appeasrs on the display screen.
This icon

will not be dismissed until maintenance has been performed or the problem cleared.

Note: The wrench icon may be on steady or flash, depending on severity. Maintenance should only be performed by qualified service
personell.

Display

Testing the Display
Press the FAN MODE and FAN SPEED buttons at the same time for 3 seconds. All of the display's icons and functions
should light up. If any of them do not light up, the display should be replaced. When the buttons are released, the display
reverts to the original display.

Electronic Control System Maintenance Operation

To Enter the Maintenance Section:
Press SYSTEM+SCHEDULE+BACK+DISPLAY/ENTER for 6 seconds.
There are 5 maintenance sub-menus M1 through M5.
Maintenance Sub-Menus

Access

M1 –
M2 –
M3 –
M4 –
M5 –
M6 –

Service Only
Service Only
Service Only
Factory Use Only
Service Only
Factory Use Only

Temperature High Limit
Temperature Low Limit
Test Mode Access
Provision Switch Setting & State
Alarms & History
Factory Use Only

Pressing the ▼or ▲key cycles through the sub-menus. Press DISPLAY/ENTER to
enter a sub-menu. The BACK key is used to exit the menu. Extreme care must
be taken when modifying parameters in the maintenance menus.

Temperature High Limit

Maintenance function 1 is ready to be selected. Press DISPLAY/ENTER to access
the function.
User presses or to increment or decrement the upper temperature limit. 99°F
is the maximum upper limit. The current stored high limit is displayed when the
screen is selected. Press the BACK key to accept the value, and exit the sub-menu
to the M1 screen.

Temperature Low Limit

Maintenance funtion 2 is ready to be selected. Press DISPLAY/ENTER to access
the fuction
User presses or to increment or decrement the lower temperature limit. 60°F is the
minimum lower limit. The current stored lower limit must be displayed when the screen
is selected. Press the BACK key to accept the value, and exit the sub-menu to the M2
screen.

M3 – Test Mode Access

Maintenance function 3 is ready to be selected. Press
DISPLAY/ENTER to access the function.
User presses the ▼or ▲key to toggle the Test Mode
ON/OFF. Press the BACK key to accept the change
and exit the sub-menu to the M3 screen.
This test selects the system mode of operation directly.
The Following functions Can be Tested
1. System Mode: Cool/Heat Pump Compressor, Electric Heat, Fan Only
2. Fan operation and speeds
Test mode Bypasses:
1. Compressor lock out (time delay)
2. All relay switch’s delays
3. All thermistors delay
4. Automatic heat/cool changeover delay
5. System settings
If M3 switch is left ON it will reset to OFF automatcally after 15 minutes of inactivity.

M4 – Switch Access (Unit Configuration)

FACTORY USE ONLY

M5 – Error Codes & History

Number of Errors

Error Code
On/Off

Error Code

Maintenance funtion 5 is ready to be selected. Press DISPLAY/ENTER to access the function.
The error code display shows the error code number on the left, and the error code
history on the right. User presses the or keys to cycle through the error codes.
The current state of the error code is shown with the On/Off icon. To exit the
maintenance sub-menu, press the BACK key to return to the M5 screen.
Shown on this display is error code 1 with 4 occurances. The current state is on.The
error code display shows the error code number on the left, and the error code history
on the right. User presses the or keys to cycle through the error codes. The
current state of the error code is shown with the On/Off icon. To exit to the
maintenance sub-menu, press the BACK key to return to the M5 screen. Shown on
this display is error code 6 with 3 occurances. The current state is off.
To Clear Error Codes’ History:
Hold the or keys simultaneously for 3 seconds. See page 56 for alarm status and error codes.

M6 – Factory Use Only

UNIT OPERATION
There are two basic ways to operate the unit - Front Panel and Wallstat. The Front Panel and Wallstat are never active at the
same time. Switching between these modes is controlled via the (FP) jumper on the Wallstat connector. When the jumper is
ON, the mode = Front Panel.

Front Panel
System Mode Sequence (SCHEDULE = OFF)
There are two system modes of operation. One for a cool only unit (see figure 1) and one for a heat-cool unit (see figure 2).
System parameters for each system mode are saved when exiting a system mode, and retrieved when entering a new
system mode.

Figure 1

System Mode: Cool Only Units

Figure 2

System Mode: Heat - Cool Units

COOL-HEAT SET POINTS
The air conditioner control system is designed to control different product configurations
with a select set of features. Some models just cool, some cool and heat with electric
heat, and others cool and heat with a heat pump and/or electric heat.
The system set points are mapped to the internal controls as shown below.

Control

1.5
1.5
Deadband

System Set Point Mapping Figure
There are 8 stored & variable set points in the system:
1 - ASPC: Auto Set Point Cool
2 - ASPH: Auto Set Point Heat
3 - CSP: Cool Only Set Point
4 - HSP: Heat Only Set Point
5 - SASPC: Scheduler Auto Set Point Cool
6 - SASPH: Scheduler Auto Set Point Heat
7 - SSPC: Scheduler Set Point Cool Only
8 - SSPH: Scheduler Set Point Heat Only

ELECTRONIC CONTROL SEQUENCE OF OPERATION
Compressor and Reversing Valve Control
Active Mode

Cooling
Heat - Heat Pump
Heat - Electric
Fan Only

Compressor

Reversing Valve State

On
On
Off
Off

De-Energized
Energized

* The Reversing valve stays in the last state until a call for heat or cooling (see figure below)

Compressor Operation:

The reversing valve only changes when required
to provide cooling or heat pump. The RV valve
stays in it's last state until required to change.

Cooling Mode

Once the ambient temperature rises past the cool demand threshold (Cool Set Point + 1.5 ˚F) (see figure below), and
the compressor is not locked out, the cooling cycle begins. As shown in the figure below, the fan is started 5 seconds
prior to the compressor. Once the ambient temperature has been lowered to the cool set point (Cool Set Point minus
.25 ˚F), the cooling cycle starts to terminate by shutting off the compressor. After a 30 seconds delay, the fan is shut
off. (See figure below for graphic details)

Heating Mode Control Operation
There are two heating methods: Heat Pump and Electric Resistance Heat.
There are 3 types of units that provide heating: Heat Pump Only (Model YS10M10)
Heat Pump with Electric Heat and Cool with Electric Heat.

Heat Control Operation Heat Pump Only
Once the ambient temperature falls below the Heating Demand Threshold
(1.5 ˚F Below the Heat Set Point Temperature), the heating cycle begins. The fan is turned on 5 seconds later. Once
the ambient temperature has been raised to the Heat Satisfied Point (Set point + .25 ˚F), the compressor is turned
off. The fan is turned off 30 seconds later. The figure below illustrates the basic heat pump operation.

Heat Control (Heat Pump Only)

Heat Pump With Electric Heat Operation
This heating is more complex due to the possibility of two heating methods. If the ambient indoor temperature is below the heat demand threshold (1.5˚F below the heat set point temperature), and the compressor is not locked out,
turn on compressor. If the ambient indoor temperature is 0.25˚F above the heat set point turn off the compressor.

If the compressor is locked out & electric heat is available:
1. Turn on the electric heat until the compressor is not locked out.
2. After lockout, turn off the electric heat, wait 5 seconds, then turn on the compressor.

If Electric Heat is Available

After the Heat button is initially pressed, the unit will run the electric heater until the initial set point is satisfied (Hot Start
Feature). After the initial start, the unit will switch to Heat Pump heat and decide between Heat Pump heat and Electric
heat based on the following two monitored conditions:

Condition 1
If the outdoor coil temperature sensor drops to 30 ˚F or less for 2 consecutive minutes, the unit will switch to electric heat
if available. Thereafter, the unit will switch back to Heat Pump heat if the outdoor coil temperature sensor rises to 45 ˚F or
greater.
If Electric Heat is not available (out of order) and the outdoor coil temperature sensor drops to 30 ˚F or less for 2
consecutive minutes, then the compressor and fan will turn off. Thereafter, the unit will switch back to Heat Pump heat if
the outdoor coil temperature rises to 45 ˚F or greater.

Heat Pump With Electric Heat Operation (Continued)
Condition 2
If the Δ (delta) (set point temperature minus the ambient indoor temperature) is greater than 5 ˚F, then the unit will switch
to electric heat, if available. The unit will continue to operate with electric heat until the heat demand is satisfied. Note that
the electric heat switches on after the Δ temp passes 5°F and the heat pump switches off. Also note that the electric heat
will run until the heat demand is satisfied. When another heat demand cycle is initiated, the heat pump will run unless the
Δ temp is greater than the electric heat threshold.

Emergency Heat
If a compressor fails in the heating season, the Emergency Heat allows the user to override the Heat Pump and heat with
electric heat only. This is controlled via the user interface (See the User Menu Functions page 12).
Note that if heat is the first demand cycle (demand cycle = call for heat or call for cooling) after power restoration, the
control system will run electric heat for the entire cycle if the unit is equipped with electric heat.

Electric Heat Operation in Cool with Electric Heat Units

When in the Heat mode, with and without Fan Mode Auto (Fan cycling):
If the indoor ambient temperature is below the Heat Demand Threshold (Heat Set Point minus 1.5 ˚F), turn on electric
heat. If Ambient is 0.3 ˚F above the Heat Set Point turn off the electric heat.

System Mode Auto

This mode provides automatic change over between cool and heat. The auto mode runs based on the room ambient
temperature vs. the Demand Thresholds. It is only available in Heat-Cool Unit.

Notes:
The Heat Demand Threshold and the Cool Demand Threshold values are derived from the Auto Set Point in the Auto
Mode (refer to page 22). There is a buffer zone as shown in figure , where no heating or cooling is allowed to occur. It is
critical that the Cool Demand Threshold be greater than the Heat Demand Threshold by a minimum of 3° while in the Auto
System Mode. For example, if a user enters a value for the Auto Cooling Set Point that violates the minimum Δ 3° rule, the
Auto Heating Set Point will adjust accordingly. This buffer zone (BAND) can be manually adjusted from 3 to 10° (see the
BAND section page 13).
When programming the schedule, the user has the flexibility to enter the schedule automatic set point cooling (SASPC)
and the schedule automatic set point heating (SSPH) set points directly. These values are monitored to ensure that they
do not violate the minimum 3° Δ rule. If a violation is detected, the opposite set point will adjust to compensate. The
individual heating and cooling rules apply to the auto mode.

Automatic Change Over Delay (Cool with Heat Units)
The change over delay ensures that any system heating or cooling over shoot does not trigger an opposite demand cycle.
The change over delay = 15 min. This timer blocks the opposite demand cycle from running until the timer expires. As an
example, if the last demand was a cool cycle, and another cool cycle is requested, the timer will not block the request.
However, if the last demand cycle was a cool cycle, and heat cycle is requested, the timer will block the request until the
change over delay is expired.

Compressor Lock Out Time
The lockout feature ensures that the compressor is de-energized for a period of time. The timer varies randomly
from 180 to 240 seconds
The compressor lockout is initiated every time the compressor is “off” due to:
(1) Satisfying the temperature set point
(2) Changing mode to fan only or heat
(3) Turning the unit off
(4) Control is first plugged in or power is restored after failure
(5) Line power is restored from a brown out condition

Wait ICON (Hour Glass)
The wait icon will be turned on when the compressor is locked out and during demand for cooling or heat pump
compressor operation. The Wait ICON will be turned off when the condition clears.

Cooling Fan Delay
Fan cycle/Auto mode only
When unit cycles cooling ON – starts the fan 5 seconds EARLY. When unit cycles cooling OFF – DELAYS the fan
off for 30 seconds
Note: this fan delay is disabled during Test Mode

Heating Fan Delay
This is only for fan Mode Auto (Fan cycles with cool/heat operation) and not for continuous fan mode. When unit
cycles Heating ON – starts the fan 5 seconds EARLY. When unit cycles Heating OFF – DELAYS the fan off for 15
seconds
Note: the fan delay is disabled during Test Mode

Fan Speed Change Delay
Relay activation is delayed by a minimum number of seconds. The default for this value is 2 seconds and is used to
eliminate relay chatter.

Fan Only System Mode
The fan is turned on and runs at the specified manually set speed.
Only the Fan is turned on. Cool or Heat operation are off.
(This is different than FAN MODE CONTINUOUS where the fan is on with the cool or heat operation).

Fan Only Rules
1. If the SYSTEM FAN ONLY MODE is selected, the Auto fan mode is disabled, and the fan mode is forced to
continuous. In addition, the auto fan speed is disabled. If the user presses the fan speed key, the menu will skip over
the auto selection. The set point temperature display is off.
2. Any fan speed may be manually selected during Fan Only Mode.

Fan Operation (Front Panel Mode)
Heat – Cool – Auto – Fan Only
Models starting with SS, SM have 4 speeds. Models with SL, and all Kuhl+ have 3 speeds

Speed Selection
1

Continuous

Fan
AUTO

Mode

Fan Only

"On" "
Turns
On or
Off with
heat or
cool
demand
"On" "

On"
Turns
On or
Off with
heat or
cool
demand
On"

"On" "
Turns
On or
Off with
heat or
cool
demand
"On" "

On"
Turns
On or
Off with
heat or
cool
demand
On"

AUTO
AUTO Operation, but never
turns Off. Uses cool set point
or heat set point vs. ambient
temperature. When there is
no demand, operate at the
lowest available speed.
AUTO operation turns On or
Off with heat or cool demand
Uses cool set point or heat
set point vs. ambient
temperature
Disabled

Table

Fan ICON Detail
The system may have a 3 or 4 speed fan. The Fan Speed ICON will Display as per the table below.

Note that in the AUTO mode, the speed of the fan will be shown by illuminating the number of bars in the speed triangle.

Fan Mapping

UNIT OPERATION WITH A WALL-STAT
Front Panel Display Operation in Wall-Stat Mode
The indoor ambient temperature sensor is disabled. All buttons are disabled with the following exception:
A. Maintenance commands.
B. The user menu for Freeze protection (Display/Enter button for Kuhl+ only units).
C. First Button push to illuminate the back light (display will dim).
Maintenance features are operational. This includes the Check Filter, Lock Panel, M3, M4, M5, and the Service
wrench icon. Under T-stat operation, as a default, the selected operating Mode (Cool, Heat or Fan) will not show on
the front panel. The Service ICON ( ) is displayed if a malfunction is detected.
Cool/Heat/Fan modes and Fan speed operations are controlled by the remote wall thermostat.
The fan speeds can be Low or Max for 4 speed units and Low or High for 3 speed units. (T-stat selected must have
2 speed capabilities)

Thermostat terminals requirements:
Must be single stage heat/cool.
For cooling only units: C, R, G, Y.
For cooling with electric heat units: C, R, G, Y, W.
For heat pump units: C, R, G, Y, W, B.
(See page 68 for RT5 T-Stat wiring diagrams)
During Heat Mode:
The B terminal must be continuously energized. The W terminal from the T-Stat must have 24 V AC output to call
for heat. The control board decides on whether to turn on the Heat Pump Heat (compressor) or Electric Resistance
Heat. The Y terminal should not have 24 VAC output during Heat Mode.

REMOVING THE FRONT COVER

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

Remove the decorative front cover by using the tool
provided (see figure below).

REMOVING THE CHASSIS

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

Remove the decorative front cover. (See figure at
left). Remove the chassis Entrygard Retainer Wire by
removing the screw at the front right bottom corner screw
(See Figure below). Save this screw for reattachment
after reinstalling the chassis.

Tighten the four (4) captive screws as indicated by the
arrows in the figure above before closing the front panel
(do not over tighten). Ensure the filter is in place.
Make sure curtains do not block the side air intake
Notes on reattaching the decorative front cover:
Align the cord notch over the cord and center the fresh
air lever. Align the cover over the User Interface
(UI) to ensure it is clear around it and it does not
depress any buttons. If not installed correctly the
wrench alert symbol could flash.

Hold the cabinet stationary then use the hand grips on
both ends of the control unit support bracket to pull the
chassis out of the cabinet (see below).

Before reinserting the chassis into the sleeve ensure to
properly reinstall the chassis seal gasket.

REPLACING THE INDOOR COIL
THERMISTOR
Replace the indoor coil sensor. Ensure to properly clip
and insulate it at the same location (see figure below).

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

Remove the decorative front cover (see page 30).
Remove all indicated screws below (8 total, see figure
below). Remove the Discharge Sensor and the User
Interface plugs from the control board.

REPLACING THE CONTROL BOARD

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

Remove the screws indicated at the side and back plate
(6 total, see figure below). Partially lift the top cover and
at the same time carefully swing out from the top, the
back and side plate.

Remove the decorative front cover (see page 30).
Disconnect discharge sensor plug (red)
Disconnect the User Interface plug (white)
Remove the 3 screws indicated below.
Pull control board and mount plate out and disconnect
the following connectors from it:
Power, capacitor, thermistors, fan, reversing valve
and heater.
Remove the hex screw holding the control board to
its mount plate. Pull out the control board (see figure
below).

Swing
Out

Low Voltage Interface Connector
WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.
All Kuhl and Kuhl + units have a low voltage interface connector through
which a Remote Wall Thermostat, Desk Control and Auxiliary Fan’s Relay
can be connected. The interface connector is located on the left side behind
the decorative front cover.
Interface Connector Location
Figure 1

Adding a Remote Wall Thermostat
An external thermostat may be added to the air conditioner to provide
remote temperature sensing and control.
Thermostat Selection
Friedrich recommends the use of either the Friedrich RT4 or RT5. These
thermostats are single stage heat/cool, manual changeover. The RT4 is a
digital display thermostat with single speed fan control. The RT5 features
a digital display, two fan speed selection, filter check light, temperature
limiting, status indicator light, room temperature offset, backlight and
battery backup. Other thermostats may be used as long as they are single
stage heat/cool and are configured correctly for the unit.
Thermostat terminals requirements:
For cooling only units: C, R, G, Y.
For cooling with electric heat units: C, R, G, Y, W.
For heat pump units: C, R, G, Y, W, B.
For two fan speeds, thermostat must have 2 fan speed selection.
During Heat Pump Mode:
The B terminal must be continuously energized. The W terminal must have
24 VAC output to call for heat. The control board decides on whether to
turn on the Heat Pump Heat (compressor) or Electric Heat. The Y terminal
should not have 24 VAC output during heat mode.

Connecting a Remote Wall
Thermostat

Table 1
Interface Connector Definitions

Front Panel. Wire jumper between FP and
F2 enables front panel operation. Jumper off
enables remote wall t-stat operation.

Used with F1 to provide 24 VAC to external
fan relay. (See above for use with FP)

Used with F2 to provide 24 VAC to
external fan relay.

Used with D1 for desk control on or off
operation.

Used with D2 for desk control on or off
operation.

Common Ground Terminal

Call for high fan

Call for low fan

To enable the remote thermostat operation, remove the jumper between
terminals FP & F2 on the interface connector. Connect the thermostat
using Figure 1 and Table 1 as a guide.
Procedure
1) Unplug the unit.
2) Unscrew and remove the decorative front cover. (Page 30)
3) Locate the Interface Connector (24 VAC terminal strip (See figure 1 at
left) and remove the jumper wire at FP and F2.
4) Make the wire connections according to the configuration needed for
your unit (see above or page 68 for wiring diagrams).

Call for heat pump reversing valve

5) Once each wire is matched and connected, the unit is now ready to be
controlled by the thermostat.

Call for compressor

6) Reattach the decorative front cover (see page 30).

Call for heating

Note: Under T-Stat operation the front panel is disabled

24V Power from Electronic Control to Wall

except the Maintenance functions (see page 29 for details).

Remote Wall Thermostat Location

Airflow Selection and Adjustment

The thermostat should not be mounted where it may be affected by drafts,
discharge air from registers (hot or cold), or heat radiated from the sun
appliances, windows etc.. The thermostat should be located about 5 Ft.
above the floor in an area of average temperature, with good air circulation.

Air flow direction adjustment

Mercury bulb type thermostats MUST be level to control temperature
accurately to the desired set-point. Electronic digital type thermostats
should be level for aesthetics.

left or right side of the discharge opening. Each of the banks of louvers
can be directed left, right, up or down in order to achieve the most optimum

move it in the direction that you would like the air to be directed. Please
louvers than the other.

Fresh air and exhaust control
Your air conditioner has the ability to bring fresh air into the room or exhaust
stale air out of the room. The control slide is found on the upper part of
the unit (See Figure).
TO BRING IN FRESH AIR – Move the lever to the Fresh Air
position
which allows outside air to enter the room. This is useful in fall and spring as
a means of bringing in fresh outside air when using FAN ONLY . It can also
be used in the summer with the compressor in the Cooling Mode if you wish.
TO EXHAUST INDOOR AIR – Move the lever to the Exhaust
position. This will allow stale air to be expelled to the outside of the dwelling.
This is especially handy in the spring or fall when indoor air tends to get
stale, or after a social gathering involving smokers, or to remove cooking
odors.
BEST PERFORMANCE – Move the lever to the Re-Circulate Position
Note: An improperly operating or poorly located remote wall thermostat
can be the source of perceived equipment problems. A careful check of the
thermostat’s location and wiring must be made then to ensure that it is not
the source of problems.

Desk Control
The unit’s electronic control has built-in provisions for connection to an
external switch to control power to the unit. The switch can be a central
desk control system or even a normally open door switch.
For desk control operation, connect one side of the switch to the D1
terminal and the other to the D2 terminal (See page 32). Whenever the
switch closes, the unit operation will stop.

Maximum Wire Length for Desk Control Switch

FRR008

Auxiliary Fan Control
The electronic control also has the ability to control a 24 VAC relay to
activate an auxiliary, or transfer fan. The outputs are listed as F1 and F2 on
the interface connector (See page 32).
To connect the relay, simply wire one side of the relay to F1 and the other
side to F2. Anytime that the fan runs, the terminals will send a 24 VAC
signal to the relay. The relay must be 24 VAC, 50mA or less.
Note: The Desk Control, Auxiliary Fan relay and wires must be field supplied.

COMPONENTS TESTING
FAN MOTOR
A single phase permanent split capacitor motor is used to drive
the evaporator blower and condenser fan. A self-resetting
overload is located inside the motor to protect against high
temperature and high amperage conditions. (See Figure 23)

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

BLOWER/FAN MOTOR - TEST
1.

Determine that capacitor is serviceable.

Disconnect fan motor wires from fan speed switch or
system switch.

Apply “live” test cord probes on black wire and common
terminal of capacitor. Motor should run at high speed.

Apply “live” test cord probes on red wire and common
terminal of capacitor. Motor should run at low speed.

Apply “live” test cord probes on each of the remaining
wires from the speed switch or system switch to test
intermediate speeds. If the control is in the “MoneySaver”
mode and the thermostat calls for cooling, the fan will
start - then stop after approximately 2 minutes; then the
fan and compressor will start together approximately 2
minutes later.

Figure 23
Blower/Fan Motor

CAPACITORS

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before servicing.
Discharge capacitor with a 20,000 Ohm 2 Watt
resistor before handling.
Failure to do so may result in personal injury,
or death.

Many motor capacitors are internally fused. Shorting the
terminals will blow the fuse, ruining the capacitor. A 20,000
ohm 2 watt resistor can be used to discharge capacitors
safely. Remove wires from capacitor and place resistor
across terminals. When checking a dual capacitor with
a capacitor analyzer or ohmmeter, both sides must be
tested.

Capacitor Check with Capacitor Analyzer
The capacitor analyzer will show whether the capacitor is
“open” or “shorted.” It will tell whether the capacitor is within
its micro farads rating and it will show whether the capacitor
is operating at the proper power-factor percentage. The
instrument will automatically discharge the capacitor when
the test switch is released.

Capacitor Connections
The starting winding of a motor can be damaged by a
shorted and grounded running capacitor. This damage
usually can be avoided by proper connection of the running
capacitor terminals.
From the supply line on a typical 230 volt circuit, a 115 volt
potential exists from the “R” terminal to ground through a
possible short in the capacitor. However, from the “S” or
start terminal, a much higher potential, possibly as high as
400 volts, exists because of the counter EMF generated
in the start winding. Therefore, the possibility of capacitor
failure is much greater when the identified terminal is
connected to the “S” or start terminal. The identified
terminal should always be connected to the supply line, or
“R” terminal, never to the “S” terminal.
When connected properly, a shorted or grounded running
capacitor will result in a direct short to ground from the “R”
terminal and will blow the line fuse. The motor protector
will protect the main winding from excessive temperature.
Dual Rated Run Capacitor Hook-up

COMPONENTS TESTING
HEATING ELEMENT
All heat pumps and electric heat models are equipped
with a heating element with the exception of model
YS10M10. The other “YS” and “ES” models are
equipped with a 3.3 KW element. The “YM” and “EM”
models are equipped with a 4.0 KW element. The
“YL” and “EL” models are equipped with a 5.2 KW
element.
Heating Element
Sample

The heating element contains a fuse link and a heater
limit switch. The fuse link is in series with the power
supply and will open and interrupt the power when the
temperature reaches 199°F or a short circuit occurs in
the heating element. Once the fuse link separates, a
new fuse link must be installed.
NOTE:
Always replace with the exact
replacement.
The heater element has a high limit control. This
control is a bimetal thermostat mounted in the top of
the heating element.
Should the fan motor fail or filter become clogged,
the high limit control will open and interrupt power to
the heater before reaching an unsafe temperature
condition.
The control is designed to open at 110°F ±6°F. Test
continuity below 110°F and for open above 110°F.
HEATING ELEMENT (Heat Pump Models)
The heating element for the “Y” model is energized
by an outdoor thermistor via the electronic control
board. The outdoor defrost thermistor is adjusted at
a predetermined temperature to bring on the heating
element and turn off the compressor. The room

TESTING THE HEATING ELEMENT

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before
servicing. Failure to follow this warning
could result in serious injury or death.

Testing of the elements can be made with an ohmmeter
across the terminals after the connecting wires
have been removed. A cold resistance reading of
approximately 14.5 ohms for the 3.3 KW heater, 11.9
ohms for the 4.0 KW heater and 9.15 ohms for the 5.2
KW heater should be registered.
DRAIN PAN VALVE
During the cooling mode of operation, condensate
which collects in the drain pan is picked up by the condenser fan blade and sprayed onto the condenser coil.
This assists in cooling the refrigerant plus evaporating
the water.
During the heating mode of operation, it is necessary
that water be removed to prevent it from freezing during
cold outside temperatures. This could cause the condenser fan blade to freeze in the accumulated water
and prevent it from turning.
To provide a means of draining this water, a bellows
type drain valve is installed over a drain opening in the
base pan.
This valve is temperature sensitive and will open when
the outside temperature reaches 40°F. The valve will
close gradually as the temperature rises above 40°F to
fully close at 60°F.

Bellows Assembly
Drain Pan Valve

REFRIGERATION SEQUENCE OF OPERATION
A good understanding of the basic operation of the
refrigeration system is essential for the service technician.
Without this understanding, accurate troubleshooting of
refrigeration system problems will be more difficult and time
consuming, if not (in some cases) entirely impossible. The
refrigeration system uses four basic principles (laws) in its
operation they are as follows:
1. “Heat always flows from a warmer body to a cooler
body.”
2. “Heat must be added to or removed from a substance
before a change in state can occur”
3. “Flow is always from a higher pressure area to a lower
pressure area.”
4. “The temperature at which a liquid or gas changes state
is dependent upon the pressure.”
The refrigeration cycle begins at the compressor. Starting
the compressor creates a low pressure in the suction line
which draws refrigerant gas (vapor) into the compressor.
The compressor then “compresses” this refrigerant, raising
its pressure and its (heat intensity) temperature.
The refrigerant leaves the compressor through the discharge
Line as a hot High pressure gas (vapor). The refrigerant
enters the condenser coil where it gives up some of its
heat. The condenser fan moving air across the coil’s finned
surface facilitates the transfer of heat from the refrigerant to
the relatively cooler outdoor air.

The refrigerant leaves the condenser Coil through the liquid
line as a warm high pressure liquid. It next will pass through
the refrigerant drier (if so equipped). It is the function of the
drier to trap any moisture present in the system, contaminants,
and large particulate matter.
The liquid refrigerant next enters the metering device. The
metering device is a capillary tube. The purpose of the
metering device is to “meter” (i.e. control or measure) the
quantity of refrigerant entering the evaporator coil.
In the case of the capillary tube this is accomplished (by
design) through size (and length) of device, and the pressure
difference present across the device.
Since the evaporator coil is under a lower pressure (due to
the suction created by the compressor) than the liquid line,
the liquid refrigerant leaves the metering device entering the
evaporator coil. As it enters the evaporator coil, the larger
area and lower pressure allows the refrigerant to expand
and lower its temperature (heat intensity). This expansion is
often referred to as “boiling”. Since the unit’s blower is moving
indoor air across the finned surface of the evaporator coil,
the expanding refrigerant absorbs some of that heat. This
results in a lowering of the indoor air temperature, hence the
“cooling” effect.
The expansion and absorbing of heat cause the liquid
refrigerant to evaporate (i.e. change to a gas). Once the
refrigerant has been evaporated (changed to a gas), it is
heated even further by the air that continues to flow across
the evaporator coil.

When a sufficient quantity of heat has been removed from
the refrigerant gas (vapor), the refrigerant will “condense”
(i.e. change to a liquid). Once the refrigerant has been
condensed (changed) to a liquid it is cooled even further by
the air that continues to flow across the condenser coil.

The particular system design determines at exactly what
point (in the evaporator) the change of state (i.e. liquid to a
gas) takes place. In all cases, however, the refrigerant must
be totally evaporated (changed) to a gas before leaving the
evaporator coil.

The RAC design determines at exactly what point (in the
condenser) the change of state (i.e. gas to a liquid) takes
place. In all cases, however, the refrigerant must be
totally condensed (changed) to a Liquid before leaving the
condenser coil.

The low pressure (suction) created by the compressor
causes the refrigerant to leave the evaporator through the
suction line as a cool low pressure vapor. The refrigerant then
returns to the compressor, where the cycle is repeated.

Suction
Line

Evaporator
Coil
Metering
Device
Refrigerant
Strainer

Discharge
Line
Condenser
Coil
Compressor
Refrigerant Drier Liquid
Line

R-410A SEALED SYSTEM REPAIR CONSIDERATIONS

WARNING
Refrigeration system under high pressure
Do not puncture, heat, expose to flame or incinerate.
Only certified refrigeration technicians should
service this equipment.
R410A systems operate at higher pressures than
R22 equipment. Appropriate safe service and
handling practicces must be used.
Only use gauge sets designed for use with R410A.
Do not use standard R22 gauge sets.

The following is a list of important considerations when working with R-410A equipment
•

R-410A pressure is approximately 60% higher than R-22 pressure.

•

R-410A cylinders must not be allowed to exceed 125 F, they may leak or rupture.

•

R-410A must never be pressurized with a mixture of air, it may become
flammable.

•

Servicing equipment and components must be specifically designed for use with R-410A and
dedicated to prevent contamination.

•

Manifold sets must be equipped with gauges capable of reading 750 psig (high side) and 200
psig (low side), with a 500-psig low-side retard.

•

Gauge hoses must have a minimum 750-psig service pressure rating

•

Recovery cylinders must have a minimum service pressure rating of 400 psig, (DOT 4BA400
and DOT BW400 approved cylinders).

•

POE (Polyol-Ester) lubricants must be used with R-410A equipment.

•

To prevent moisture absorption and lubricant contamination, do not leave the refrigeration
system open to the atmosphere longer than 1 hour.

•

Weigh-in the refrigerant charge into the high side of the system.

•

Introduce liquid refrigerant charge into the high side of the system.

•

For low side pressure charging of R-410A, use a charging adaptor.

•

Use Friedrich approved R-410A filter dryers only.

R-410A SEALED REFRIGERATION SYSTEM REPAIRS
IMPORTANT
SEALED SYSTEM REPAIRS TO COOL-ONLY MODELS REQUIRE THE INSTALLATION OF A LIQUID LINE DRIER.

EQUIPMENT REQUIRED:
1. Voltmeter

2. Ammeter

10. Low Pressure Gauge - (-30 to 200 lbs.)

3. Ohmmeter

11. Vacuum Gauge - (0 - 1000 microns)

4. E.P.A. Approved Refrigerant Recovery System

12. Facilities for flowing nitrogen through refrigeration tubing
during all brazing processes.

5. Vacuum Pump (capable of 200 microns or less
vacuum.)
6. Acetylene Welder

EQUIPMENT MUST BE CAPABLE OF:
1. Recovering refrigerant to EPA required levels.

7. Electronic Halogen Leak Detector capable of
detecting HFC (Hydrofluorocarbon) refrigerants.
8. Accurate refrigerant charge measuring device such
as:
a. Balance Scales - 1/2 oz. accuracy
b. Charging Board - 1/2 oz. accuracy

WARNING
RISK OF ELECTRIC SHOCK
Unplug and/or disconnect all electrical power
to the unit before performing inspections,
maintenances or service.
Failure to do so could result in electric shock,
serious injury or death.

WARNING
HIGH PRESSURE HAZARD
Sealed Refrigeration System contains refrigerant
and oil under high pressure.
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with refrigerants.
Failure to follow these procedures could
result in serious injury or death.

Refrigerant Charging
NOTE: Because the RAC system is a sealed system, service
process tubes will have to be installed. First install a line tap
and remove refrigerant from system. Make necessary sealed
system repairs and vacuum system. Crimp process tube
line and solder end shut. Do not leave a service valve in the
sealed system.

High Pressure Gauge - (0 to 750 lbs.)

2. Evacuation from both the high side and low side of the
system simultaneously.
3. Introducing refrigerant charge into high side of the
system.
4. Accurately weighing the refrigerant charge introduced
into the system.
Proper refrigerant charge is essential to proper unit operation.
Operating a unit with an improper refrigerant charge will
result in reduced performance (capacity) and/or efficiency.
Accordingly, the use of proper charging methods during
servicing will insure that the unit is functioning as designed
and that its compressor will not be damaged.
Too much refrigerant (overcharge) in the system is just as bad
(if not worse) than not enough refrigerant (undercharge). They
both can be the source of certain compressor failures if they
remain uncorrected for any period of time. Quite often, other
problems (such as low air flow across evaporator, etc.) are
misdiagnosed as refrigerant charge problems. The refrigerant
circuit diagnosis chart will assist you in properly diagnosing
these systems.
An overcharged unit will at times return liquid refrigerant
(slugging) back to the suction side of the compressor eventually
causing a mechanical failure within the compressor. This
mechanical failure can manifest itself as valve failure, bearing
failure, and/or other mechanical failure. The specific type of
failure will be influenced by the amount of liquid being returned,
and the length of time the slugging continues.
Not enough refrigerant (undercharge) on the other hand, will
cause the temperature of the suction gas to increase to the point
where it does not provide sufficient cooling for the compressor
motor. When this occurs, the motor winding temperature will
increase causing the motor to overheat and possibly cycle open
the compressor overload protector. Continued overheating of
the motor windings and/or cycling of the overload will eventually
lead to compressor motor or overload failure.

Method Of Charging / Repairs
The acceptable method for charging the WallMaster system
is the Weighed in Charge Method. The weighed in charge
method is applicable to all units. It is the preferred method to
use, as it is the most accurate.
The weighed in method should always be used whenever
a charge is removed from a unit such as for a leak repair,
compressor replacement, or when there is no refrigerant
charge left in the unit. To charge by this method, requires the
following steps:
1. Install a piercing valve to remove refrigerant from the
sealedsystem. (Piercing valve must be removed from the
system before recharging.)
2. Recover Refrigerant in accordance with EPA regulations.

WARNING
BURN HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with a torch.
Failure to follow these procedures could
result in moderate or serious injury.

3. Install a process tube to sealed system.

CAUTION
FREEZE HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with liquid refrigerant.
Failure to follow these procedures could
result in minor to moderate injury.

4. Make necessary repairs to system.
5. Evacuate system to 200 microns or less.
6. Weigh in refrigerant with the property quantity of R-410A
refrigerant.
7. Start unit, and verify performance.

WARNING

ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation.

HIGH PRESSURE HAZARD
Sealed Refrigeration System contains refrigerant
and oil under high pressure.

Extreme care must be used, if it becomes
necessary to work on equipment with power
applied.

Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with refrigerants.

Failure to do so could result in serious injury or
death.

Failure to follow these procedures could
result in serious injury or death.

Undercharged Refrigerant Systems
An undercharged system will result in poor performance
(low pressures, etc.) in both the heating and cooling
cycle.
Whenever you service a unit with an undercharge of
refrigerant, always suspect a leak. The leak must be
repaired before charging the unit.

A check of the amperage drawn by the compressor
motor should show a lower reading. (Check the Unit
Specification.) After the unit has run 10 to 15 minutes,
check the gauge pressures. Gauges connected to system
with an undercharge will have low head pressures and
substantially low suction pressures.

To check for an undercharged system, turn the unit on,
allow the compressor to run long enough to establish
working pressures in the system (15 to 20 minutes).
During the cooling cycle you can listen carefully at the exit
of the metering device into the evaporator; an intermittent
hissing and gurgling sound indicates a low refrigerant
charge. Intermittent frosting and thawing of the evaporator
is another indication of a low charge, however, frosting
and thawing can also be caused by insufficient air over
the evaporator.
Checks for an undercharged system can be made at
the compressor. If the compressor seems quieter than
normal, it is an indication of a low refrigerant charge.

Overcharged Refrigerant Systems
Compressor amps will be near normal or higher.
Noncondensables can also cause these symptoms. To
confirm, remove some of the charge, if conditions improve,
system may be overcharged. If conditions don’t improve,
Noncondensables are indicated.
Whenever an overcharged system is indicated, always
make sure that the problem is not caused by air flow
problems. Improper air flow over the evaporator coil may
indicate some of the same symptoms as an over charged
system.
An overcharge can cause the compressor to fail, since it
would be “slugged” with liquid refrigerant.
The charge for any system is critical. When the compressor
is noisy, suspect an overcharge, when you are sure that
the air quantity over the evaporator coil is correct. Icing

of the evaporator will not be encountered because the
refrigerant will boil later if at all. Gauges connected to
system will usually have higher head pressure (depending
upon amount of over charge). Suction pressure should be
slightly higher.

Restricted Refrigerant System
Troubleshooting a restricted refrigerant system can be
difficult. The following procedures are the more common
problems and solutions to these problems. There are two
types of refrigerant restrictions: Partial restrictions and
complete restrictions.
A partial restriction allows some of the refrigerant to
circulate through the system.
With a complete restriction there is no circulation of
refrigerant in the system.

at the metering device entrance to the evaporator. The
evaporator in a partial restriction could be partially frosted
or have an ice ball close to the entrance of the metering
device. Frost may continue on the suction line back to the
compressor.
Often a partial restriction of any type can be found by feel,
as there is a temperature difference from one side of the
restriction to the other.

Gauges connected to a completely restricted system will
run in a deep vacuum. When the unit is shut off, the gauges
will not equalize at all.

With a complete restriction, there will be no sound at the
metering device entrance. An amperage check of the
compressor with a partial restriction may show normal
current when compared to the unit specifi cation. With a
complete restriction the current drawn may be considerably
less than normal, as the compressor is running in a deep
vacuum (no load.) Much of the area of the condenser will
be relatively cool since most or all of the liquid refrigerant
will be stored there.

A quick check for either condition begins at the evaporator.
With a partial restriction, there may be gurgling sounds

The following conditions are based primarily on a system
in the cooling mode.

Restricted refrigerant systems display the same symptoms
as a “low-charge condition.”
When the unit is shut off, the gauges may equalize very
slowly.

HERMETIC COMPONENTS CHECK

WARNING
WARNING

BURN HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with a torch.

CUT/SEVER HAZARD
Be careful with the sharp edges and corners.
Wear protective clothing and gloves, etc.

Failure to follow these procedures could
result in moderate or serious injury.

Failure to do so could result in serious injury.

METERING DEVICE
Capillary Tube Systems
All units are equipped with capillary tube metering
devices.

Switch the unit to the heating mode and observe the
gauge readings after a few minutes running time. If
the system pressure is lower than normal, the heating
capillary is restricted.

If the operating pressures are lower than normal in both
the heating and cooling mode, the cooling capillary is
restricted.

Checking for restricted capillary tubes.
1. Connect pressure gauges to unit.
2. Start the unit in the cooling mode. If after a few minutes
of operation the pressures are normal, the check valve
and the cooling capillary are not restricted.

CHECK VALVE

A unique two-way check valve is used on the reverse cycle
heat pumps. It is pressure operated and used to direct the
flow of refrigerant through a single filter drier and to the
proper capillary tube during either the heating or cooling
cycle.
One-way Check Valve
(Heat Pump Models)

NOTE: The slide (check) inside the valve is made of teflon.
Should it become necessary to replace the check valve,
place a wet cloth around the valve to prevent overheating
during the brazing operation.
CHECK VALVE OPERATION
In the cooling mode of operation, high pressure liquid enters
the check valve forcing the slide to close the opposite port
(liquid line) to the indoor coil. Refer to refrigerant flow chart.
This directs the refrigerant through the filter drier and cooling
capillary tube to the indoor coil.

In the heating mode of operation, high pressure refrigerant
enters the check valve from the opposite direction, closing
the port (liquid line) to the outdoor coil. The flow path of
the refrigerant is then through the filter drier and heating
capillary to the outdoor coil.
Failure of the slide in the check valve to seat properly in
either mode of operation will cause flooding of the cooling
coil. This is due to the refrigerant bypassing the heating or
cooling capillary tube and entering the liquid line.
COOLING MODE
In the cooling mode of operation, liquid refrigerant from
condenser (liquid line) enters the cooling check valve
forcing the heating check valve shut. The liquid refrigerant
is directed into the liquid dryer after which the refrigerant
is metered through cooling capillary tubes to evaporator.
(Note: liquid refrigerant will also be directed through the
heating capillary tubes in a continuous loop during the
cooling mode).
HEATING MODE
In the heating mode of operation, liquid refrigerant from
the indoor coil enters the heating check valve forcing the
cooling check valve shut. The liquid refrigerant is directed
into the liquid dryer after which the refrigerant is metered
through the heating capillary tubes to outdoor coils. (Note:
liquid refrigerant will also be directed through the cooling
capillary tubes in a continuous loop during the heating
mode).

REVERSING VALVE DESCRIPTION/OPERATION

WARNING
ELECTRIC SHOCK HAZARD
Disconnect power to the unit before servicing.
Failure to follow this warning could result in
serious injury or death.

The Reversing Valve controls the direction of refrigerant
flow to the indoor and outdoor coils. It consists of a
pressure-operated, main valve and a pilot valve actuated
by a solenoid plunger. The solenoid is energized during the
heating cycle only. The reversing valves used in the RAC
system is a 2-position, 4-way valve.
The single tube on one side of the main valve body is the
high-pressure inlet to the valve from the compressor. The
center tube on the opposite side is connected to the low
pressure (suction) side of the system. The other two are
connected to the indoor and outdoor coils. Small capillary
tubes connect each end of the main valve cylinder to the

“A” and “B” ports of the pilot valve. A third capillary is a common
return line from these ports to the suction tube on the main
valve body. Four-way reversing valves also have a capillary
tube from the compressor discharge tube to the pilot valve.
The piston assembly in the main valve can only be shifted
by the pressure differential between the high and low sides
of the system. The pilot section of the valve opens and
closes ports for the small capillary tubes to the main valve
to cause it to shift.
NOTE: System operating pressures must be near
normal before valve can shift.

TESTING THE REVERSING VALVE
SOLENOID COIL

WARNING
ELECTRIC SHOCK HAZARD
Unplug and/or disconnect all electrical power
to the unit before performing inspections,
maintenances or service.
Failure to do so could result in electric shock,
serious injury or death.

The solenoid coil is an electromagnetic type coil mounted
on the reversing valve and is energized during the
operation of the compressor in the heating cycle.
1. Turn off high voltage electrical power to unit.
2. Unplug line voltage lead from reversing valve coil.
3. Check for electrical continuity through the coil. If you
do not have continuity replace the coil.
4. Check from each lead of coil to the copper liquid line
as it leaves the unit or the ground lug. There should
be no continuity between either of the coil leads
and ground; if there is, coil is grounded and must be
replaced.

Should the valve fail to shift from coooling to heating,
block the air flow through the outdoor coil and allow the
discharge pressure to build in the system. Then switch
the system from heating to cooling.
If the valve is stuck in the heating position, block the air
flow through the indoor coil and allow discharge pressure
to build in the system. Then switch the system from
heating to cooling.
Should the valve fail to shift in either position after
increasing the discharge pressure, replace the valve.
Dented or damaged valve body or capillary tubes can
prevent the main slide in the valve body from shifting.
If you determing this is the problem, replace the reversing
valve.
After all of the previous inspections and checks have
been made and determined correct, then perform the
“Touch Test” on the reversing valve.

5. If coil tests okay, reconnect the electrical leads.
6. Make sure coil has been assembled correctly.
NOTE: Do not start unit with solenoid coil removed from
valve, or do not remove coil after unit is in operation. This
will cause the coil to burn out.

CHECKING THE REVERSING VALVE
NOTE: You must have normal operating pressures before
the reversing valve can shift.

Check the operation of the valve by starting the system
and switching the operation from “Cooling” to “Heating”
and then back to “Cooling”. Do not hammer on valve.
Occasionally, the reversing valve may stick in the heating
or cooling position or in the mid-position.
When sluggish or stuck in the mid-position, part of the
discharge gas from the compressor is directed back to the
suction side, resulting in excessively high suction pressure.
44

Reversing Valve in Heating Mode

Touch Test in Heating/Cooling Cycle

WARNING
BURN HAZARD
Certain unit components operate at
temperatures hot enough to cause burns.

Protect new valve body from heat while brazing with plastic
heat sink (Thermo Trap) or wrap valve body with wet
rag.

Fit all lines into new valve and braze lines into new
valve.

Proper safety procedures must be followed,
and proper protective clothing must be
worn.

WARNING
EXPLOSION HAZARD
The use of nitrogen requires a pressure
regulator. Follow all safety procedures and
wear protective safety clothing etc.

Failure to follow these procedures could
result in minor to moderate injury.

The only definite indications that the slide is in the midposition is if all three tubes on the suction side of the valve
are hot after a few minutes of running time.
NOTE: A condition other than those illustrated above, and
on Page 44, indicate that the reversing valve is not shifting
properly. Both tubes shown as hot or cool must be the same
corresponding temperature.

Procedure For Changing Reversing Valve

NOTICE

Failure to follow proper safety procedures
could result in serious injury or death.
8.

Pressurize sealed system with a combination of R-410A
and nitrogen and check for leaks, using a suitable leak
detector. Recover refrigerant per EPA guidelines.

Once the sealed system is leak free, install solenoid coil
on new valve and charge the sealed system by weighing
in the proper amount and type of refrigerant as shown
on rating plate. Crimp the process tubes and solder the
ends shut. Do not leave Schrader or piercing valves in
the sealed system.

NOTE: When brazing a reversing valve into the system, it is
of extreme importance that the temperature of the valve does
not exceed 250°F at any time.
Wrap the reversing valve with a large rag saturated with
water. “Re-wet” the rag and thoroughly cool the valve after
each brazing operation of the four joints involved.
The wet rag around the reversing valve will eliminate
conduction of heat to the valve body when brazing the line
connection.

FIRE HAZARD
The use of a torch requires extreme care and proper
judgment. Follow all safety recommended precautions
and protect surrounding areas with fire proof materials.
Have a fire extinguisher readily available. Failure to follow
this notice could result in moderate to serious property
damage.

Install Process Tubes. Recover refrigerant from sealed
system. PROPER HANDLING OF RECOVERED
REFRIGERANT ACCORDING TO EPA REGULATIONS
IS REQUIRED.

Remove solenoid coil from reversing valve. If coil is to
be reused, protect from heat while changing valve.

Unbraze all lines from reversing valve.

Clean all excess braze from all tubing so that they will
slip into fittings on new valve.

Remove solenoid coil from new valve.

COMPRESSOR CHECKS

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation. Extreme care must be used, if it
becomes necessary to work on equipment with
power applied.
Failure to do so could result in serious injury or
death.

Locked Rotor Voltage (L.R.V.) Test
Locked rotor voltage (L.R.V.) is the actual voltage available
at the compressor under a stalled condition.

Single Phase Connections
Disconnect power from unit. Using a voltmeter, attach one
lead of the meter to the run “R” terminal on the compressor
and the other lead to the common “C” terminal of the compressor. Restore power to unit.

Determine L.R.V.
Start the compressor with the volt meter attached; then stop
the unit. Attempt to restart the compressor within a couple
of seconds and immediately read the voltage on the meter.
The compressor under these conditions will not start and will
usually kick out on overload within a few seconds since the
pressures in the system will not have had time to equalize.
Voltage should be at or above minimum voltage of 197 VAC,
as specified on the rating plate. If less than minimum, check
for cause of inadequate power supply; i.e., incorrect wire
size, loose electrical connections, etc.

Amperage (L.R.A.) Test
The running amperage of the compressor is the most
important of these readings. A running amperage higher
than that indicated in the performance data indicates that a
problem exists mechanically or electrically.

Single Phase Running and L.R.A. Test
NOTE: Consult the specification and performance section
for running amperage. The L.R.A. can also be found on the
rating plate.
Select the proper amperage scale and clamp the meter
probe around the wire to the “C” terminal of the compressor.
Turn on the unit and read the running amperage on the
meter. If the compressor does not start, the reading will
indicate the locked rotor amperage (L.R.A.).

Overloads
The compressor is equipped with either an external or
internal overload which senses both motor amperage
and winding temperature. High motor temperature or
amperage heats the overload causing it to open, breaking
the common circuit within the compressor.

Heat generated within the compressor shell, usually due
to recycling of the motor, is slow to dissipate. It may take
anywhere from a few minutes to several hours for the
overload to reset.

Checking the Overloads

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation. Extreme care must be used, if it
becomes necessary to work on equipment
with power applied.
Failure to do so could result in serious injury or
death.

WARNING
BURN HAZARD
Certain unit components operate at
temperatures hot enough to cause burns.
Proper safety procedures must be followed,
and proper protective clothing must be
worn.

Failure to follow this warning could result
in moderate to serious injury.
External Overloads
With power off, remove the leads from compressor
terminals. If the compressor is hot, allow the overload
to cool before starting check. Using an ohmmeter, test
continuity across the terminals of the external overload.
If you do not have continuity; this indicates that the
overload is open and must be replaced.
Interrnal Overloads
Some model compressors are equipped with an internal
overload. The overload is embedded in the motor
windings to sense the winding temperature and/or current
draw. The overload is connected in series with the
common motor terminal.
Should the internal temperature and/or current draw
become excessive, the contacts in the overload will
open, turning off the compressor. The overload will
automatically reset, but may require several hours before
the heat is dissipated.
Checking the Internal Overload
1. With no power to unit, remove the leads from the
compressor terminals.
2. Using an ohmmeter, test continuity between terminals
C-S and C-R. If no continuity, the compressor overload is
open and the compressor must be replaced.

Single Phase Resistance Test

WARNING

Many compressor failures are caused by the following
conditions:
1.

Improper air flow over the evaporator.

Overcharged refrigerant system causing liquid to be
returned to the compressor.

Restricted refrigerant system.

Lack of lubrication.

Remove the leads from the compressor terminals and set
the ohmmeter on the lowest scale (R x 1).

Liquid refrigerant returning to compressor causing oil
to be washed out of bearings.

Touch the leads of the ohmmeter from terminals common
to start (“C” to “S”). Next, touch the leads of the ohmmeter
from terminals common to run (“C” to “R”).

Noncondensables such as air and moisture in
the system. Moisture is extremely destructive to a
refrigerant system.

Capacitor (see page 34).

ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation. Extreme care must be used, if it
becomes necessary to work on equipment
with power applied.
Failure to do so could result in serious injury or
death.

Add values “C” to “S” and “C” to “R” together and
check resistance from start to run terminals (“S” to “R”).
Resistance “S” to “R” should equal the total of “C” to “S”
and “C” to “R.”
In a single phase PSC compressor motor, the highest
value will be from the start to the run connections (“S” to
“R”). The next highest resistance is from the start to the
common connections (“S” to “C”). The lowest resistance
is from the run to common. (“C” to “R”) Before replacing a
compressor, check to be sure it is defective.
GROUND TEST
Use an ohmmeter set on its highest scale. Touch one
lead to the compressor body (clean point of contact as
a good connection is a must) and the other probe in turn
to each compressor terminal. If a reading is obtained the
compressor is grounded and must be replaced.
Check the complete electrical system to the compressor
and compressor internal electrical system, check to be
certain that compressor is not out on internal overload.
Complete evaluation of the system must be made
whenever you suspect the compressor is defective. If
the compressor has been operating for sometime, a
careful examination must be made to determine why the
compressor failed.

CHECKING COMPRESSOR EFFICIENCY
The reason for compressor inefficiency is normally due
to broken or damaged suction and/or discharge valves,
reducing the ability of the compressor to pump refrigerant
gas.

This condition can be checked as follows:
1. Install a piercing valve on the suction and discharge or
liquid process tube.
2. Attach gauges to the high and low sides of the system.
3. Start the system and run a “cooling or heating perfor
mance test.” If test shows:
A. Below normal high side pressure
B. Above normal low side pressure
C. Low temperature difference across coil
The compressor valves are faulty - replace the
compressor.

COMPRESSOR REPLACEMENT
Recommended procedure for compressor
replacement

After all refrigerant has been recovered, disconnect
suction and discharge lines from the compressor and
remove compressor. Be certain to have both suction
and discharge process tubes open to atmosphere.

Carefully pour a small amount of oil from the suction
stub of the defective compressor into a clean
container.

Using an acid test kit (one shot or conventional kit), test
the oil for acid content according to the instructions
with the kit.

If any evidence of a burnout is found, no matter how
slight, the system will need to be cleaned up following
proper procedures.

Install the replacement compressor.

Be certain to perform all necessary electrical and
refrigeration tests to be sure the compressor is
actually defective before replacing.

WARNING

HIGH PRESSURE HAZARD
Sealed Refrigeration System contains refrigerant
and oil under high pressure.

EXPLOSION HAZARD
The use of nitrogen requires a pressure
regulator. Follow all safety procedures and
wear protective safety clothing etc.

Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with refrigerants.

Failure to follow proper safety procedures
result in serious injury or death.

Failure to follow these procedures could
result in serious injury or death.

Recover all refrigerant from the system though
the process tubes. PROPER HANDLING OF
RECOVERED REFRIGERANT ACCORDING TO
EPA REGULATIONS IS REQUIRED. Do not use
gauge manifold for this purpose if there has been
a burnout. You will contaminate your manifold and
hoses. Use a Schrader valve adapter and copper
tubing for burnout failures.

8. Pressurize with a combination of R-410A and nitrogen
and leak test all connections with an electronic or
Halide leak detector. Recover refrigerant and repair
any leaks found.
Repeat Step 8 to insure no more leaks are present.
9.

WARNING
HIGH TEMPERATURES
Extreme care, proper judgment and all safety
procedures must be followed when testing,
troubleshooting, handling or working around
unit while in operation with high temperature
components. Wear protective safety aids
such as: gloves, clothing etc.

CAUTION
FREEZE HAZARD
Proper safety procedures must be followed,
and proper protective clothing must be worn
when working with liquid refrigerant.

Failure to do so could result in serious burn
injury.

Failure to follow these procedures could
result in minor to moderate injury.

NOTICE
FIRE HAZARD
The use of a torch requires extreme care and proper
judgment. Follow all safety recommended precautions
and protect surrounding areas with fire proof materials.
Have a fire extinguisher readily available. Failure to follow
this notice could result in moderate to serious property
damage.

Evacuate the system with a good vacuum pump capable
of a final vacuum of 200 microns or less. The system
should be evacuated through both liquid line and suction
line gauge ports. While the unit is being evacuated, seal
all openings on the defective compressor. Compressor
manufacturers will void warranties on units received not
properly sealed. Do not distort the manufacturers tube
connections.

10.

Recharge the system with the correct amount of
refrigerant. The proper refrigerant charge will be
found on the unit rating plate. The use of an accurate
measuring device, such as a charging cylinder,
electronic scales or similar device is necessary.

SPECIAL PROCEDURE IN THE CASE OF MOTOR
COMPRESSOR BURNOUT

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before service or
installation.
Failure to do so may result in personal injury,
or death.

WARNING
EXPLOSION HAZARD
The use of nitrogen requires a pressure
regulator. Follow all safety procedures and
wear protective safety clothing etc.
Failure to follow proper safety procedures
result in serious injury or death.

1. Recover all refrigerant and oil from the system.
2. Remove compressor, capillary tube and filter drier
from the system.
3. Flush evaporator condenser and all connecting
tubing with dry nitrogen or equivalent. Use approved
flushing agent to remove all contamination from
system. Inspect suction and discharge line for
carbon deposits. Remove and clean if necessary.
Ensure all acid is neutralized.
4. Reassemble the system, including new drier strainer
and capillary tube.
5. Proceed with step 8-10 on previous page.
ROTARY AND SCROLL COMPRESSOR SPECIAL
TROUBLESHOOTING AND SERVICE
Basically, troubleshooting and servicing rotary compressors is the same as on the reciprocating compressor with
only one main exception:
NEVER, under any circumstances, liquid charge a rotarycompressor through the LOW side. Doing so would cause
permanent damage to the new compressor.

ROUTINE MAINTENANCE

WARNING
ELECTRIC SHOCK HAZARD
Turn off electric power before inspections,
maintenances, or service.
Extreme care must be used, if it becomes
necessary to work on equipment with power
applied.
Failure to do so could result in serious injury
or death.

WARNING

COILS AND BASE PAN
The indoor coil (evaporator coil), the outdoor coil
(condenser coil) and base pan should be inspected
periodically (yearly or bi-yearly) and cleaned of all
debris (lint, dirt, leaves, paper, etc.). Clean the coils
and base pan with a soft brush and compressed air
or vacuum. If using a pressure washer, be careful
not to bend the aluminium fin pack. Use a sweeping
up and down motion in the direction of the vertical
aluminum fin pack when pressure cleaning coils.
Cover all electrical components to protect them from
water or spray. Allow the unit to dry thoroughly before
reinstalling it in the sleeve.
NOTE:

Do not use a caustic coil cleaning agent on coils or base pan.
Use a biodegradable cleaning agent and degreaser. The use
of harsh c leaning materials may lead to deterioration o f the

NOTE:

It is e xtremely i mportant t o insure t hat none o f the electrical
and/or electronic parts of the unit get wet. Be sure to cover all
electrical components to protect them from water or spray.

EXCESSIVE WEIGHT HAZARD
Use two people to lift or carry the unit, and wear
proper protective clothing.
Failure to do so may result in personal injury.

WARNING
CUT/SEVER HAZARD
Be careful with the sharp edges and corners.
Wear protective clothing and gloves, etc.
Failure to do so could result in serious injury.

NOTICE
Units are to be inspected and serviced by qualified service
personnel only. Use proper protection on surrounding
property. Failure to follow this notice could result in
moderate or serious property damage.

NOTICE
Do not use a caustic coil cleaning agent on coils or base
pan. Use a biodegradable cleaning agent and degreaser,
to prevent damage to the coil and/or base pan.

AIR FILTER
The air filter should be inspected weekly and cleaned
if needed by vacuuming with a dust attachment or
by cleaning in the sink using warm water and a mild
dishwashing detergent. Dry the filter thoroughly before
reinstalling. Use caution as the coil surface can be sharp.
TO REMOVE, WASH AND REPLACE FILTER
Lower front panel. Use handle on filter to flex filter
up and out of retainer. Remove filter from unit. Clean
filter monthly or more frequently if needed. Refer to
accessories section for filter options.
50

BLOWER WHEEL / HOUSING / CONDENSER FAN /
SHROUD
Inspect the indoor blower and its housing, evaporator
blade, condenser fan blade and condenser shroud
periodically (yearly or bi-yearly) and clean of all debris
(lint, dirt, mold, fungus, etc.). Clean the blower housing
area and blower wheel with an antibacterial / antifungal
cleaner. Use a biodegradable cleaning agent and
degreaser on condenser fan and condenser shroud.
Use warm or cold water when rinsing these items.
Allow all items to dry thoroughly before reinstalling
them.
ELECTRONIC / ELECTRICAL / MECHANICAL
Periodically (at least yearly or bi-yearly): inspect
all control components: electronic, electrical and
mechanical, as well as the power supply. Use proper
testing instruments (voltmeter, ohmmeter, ammeter,
wattmeter, etc.) to perform electrical tests. Use an air
conditioning or refrigeration thermometer to check
room, outdoor and coil operating temperatures.
BLOWER/FAN MOTOR
The motor is permanently lubricated.

ROUTINE MAINTENANCE (Continued)

NOTICE
Do not drill holes in the bottom of the drain pan or the
underside of the unit. Not following this notice could
result in damage to the unit or condensate water leaking
inappropriately which could cause water damage to
surrounding property.

SLEEVE / DRAIN
Inspect the sleeve and drain system periodically (at least yearly or bi-yearly) and clean of all obstructions and
debris. Clean both areas with an antibacterial and antifungal cleaner. Rinse both items thoroughly with water and
ensure that the drain outlets are operating correctly. Check the sealant around the sleeve and reseal areas as
needed.
DECORATIVE FRONT COVER
Clean the front cover when needed. Use a mild detergent. Wash and rinse with warm water. Allow it to dry
thoroughly before reinstalling it in the chassis.
The decorative front and the cabinet can be cleaned with warm water and a mild liquid detergent. Do NOT use
solvents or hydrocarbon based cleaners such as acetone, naphtha, gasoline, benzene, etc.
Use a damp (not wet) cloth when cleaning the control area to prevent water from entering the unit, and possibly
damaging the electronic control.
CLEARANCES
Inspect the surrounding area (inside and outside) to ensure that the unit’s clearances have not been compromised or
altered.

Accumulator
Compressor
Fresh Air Vent

Outdoor Grille
Discharge Air

Reversing Valve
Evaporator Coil
Condenser Coil

Electronic Control
Board

Sleeve

Control Key Pad
Support Bar
Blower Wheel
Air Intake From
Sides and Bottom
Control Key Pad
(User Interface)

Air Intake Vents
Fan Blade
Fan/Blower Motor
Base Pan
Chassis Pull
Out Handle

ROUTINE MAINTENANCE (Continued)
Standard Filter Cleaning Installation Instructions
3

STEP 2.

STEP 1.

NOTE:
Figure 1

Figure 3

FILTER

FILTER
GRIP

Remove the filter by grabbing it from its handle, lifting it up and swinging
it out.
Figure 2

STEP 3.

Swing the front frame open. Clean the front frame by washing

Figure 4

FILTER
GRIP
TOP TAB
FRONT
FRAME WITH
STANDARD
MESH FILTER

HANDLE

STEP 4.
STEP 5.
NOTE:

the inside of the front door.
the tab in the frame stops the handle from sliding in, slide the
filter halfway up, tilt it towards the front of you, then gently slide
it up fully. Do not force the handle into the frame.

ROUTINE MAINTENANCE (Continued)

After Maintenance/Repair
Start-up Checklist and Notes
Inspect and ensure that all components and accessories have been
installed properly and that they have not been damaged during the
installation progress.
Check the condensate water drain(s) to ensure that they are adequate
for the removal of condensate water, and that they meet the approval
of the end user.
Ensure that all installation instructions concerning clearances around
the unit have been adhered to. Check to ensure that the unit air filter,
indoor coil, and outdoor coil are free from any obstructions.
Ensure that the circuit breaker(s) or fuse(s) and supply circuit wire
size have been sized correctly. If the unit was supplied with a power
supply cord, insure that it is stored properly.
Ensure that the entire installation is in compliance with all applicable
national and local codes and ordinances having jurisdiction.
Secure components and accessories, such as a decorative front
cover.
Start the unit and check for proper operation of all components in
each mode of operation.
Instruct the owner or operator of the units operation, and the
manufacturer's Routine Maintenance.
NOTE:

A log for recording the dates of maintenance and/or service is
recommended.

Heat pumps operate differently
If your unit is a "Y", or heat pump model, there are some things that you
will want to be aware of. Some functions of a heat pump differ from your
unit when it is used for heating:
1.

It is normal for ice to form on the outdoor coil of the heat pump.
Moisture in the outside air, passing over the coil when very cold,
will form ice.

If the outdoor temperature drops below 37° F (3° C), your heat
pump will automatically turn on the electric resistance heat. When
the temperature rises to 40° F (4° C), the compressor will resume
the heat pump operation. If your unit is a 115 volt model (YS10),
it is designed for use in warmer climates and does not have an
electrical heat feature, and will not provide adequate heat below
37° F (2.8° C).

CONTROL PANEL BATTERY CHANGE
PROCEDURE
Remove the grille, by loosening four (4) captive screws (See Figure 1).
Remove one (1) screw on the battery retaining door (See Figure 2). Remove
and replace the battery (CR2450). Reinstall the battery retaining door. Align
the grille guide pins then tighten the four (4) captive screws. Before closing
the grille panel door, check the filter. Clean or replace it as necessary.

Figure
Figure 1

Present the owner or operator of the equipment with the name,
address and telephone number of the Authorized Friedrich Warranty
Service Company in the area for future reference if necessary.

NOTE: This is a warm weather appliance

USE HAND TOOLS
DO NOT OVER TIGHTEN

The air conditioner is designed to cool in warm weather when the outside
temperature is above 60° F (15.6° C) and below 115° F (46.1° C), so it won't
cool a room if it is already cool outside. If you want to cool a room in the
spring or fall, select the FAN ONLY mode and set the Fresh Air/Exhaust
air control to Fresh Air. This will bring in a supply of cooler outside air.

Condensation is normal
Air conditioners actually pump the heat and humidity from your room to the
outside. Humidity becomes water, and your air conditioner will use most of
the water to keep the outside coil cool. If there is excessive humidity, there
may be excess water that will drip outside. This is normal operation.

Frosting
This usually occurs because of insufficient airflow across the coils, a dirty
filter, cool damp weather, or all of these. Set the SYSTEM mode to FAN
ONLY and the frost will disappear. Setting the thermostat a little warmer
will probably prevent the frosting from recurring.

1. USE HAND TOOLS WHEN INSTALLING AND
REMOVING FRONT PANEL.
DO NOT OVERTIGHTEN SCREWS.
2. DISCONNECT POWER AND FOLLOW ALL
LABELED WARNINGS WHEN FRONT PANEL
IS REMOVED.

FRR010

Figure
Figure 2

Noises
All air conditioners make some noise. Friedrich units are designed to operate
as quietly as possible. An air conditioner mounted in a wall is quieter than
one mounted in a window. It is important to ensure that the chassis seal
gasket is properly installed (refer to installation instructions).

Battery type: Lithium, 3 Volts, #CR2450
53

Service and Assistance
Before calling for service, please check the “Troubleshooting Tips” section
on pages 40 and 41. This may help you to find the answer to your problem,
avoid unnecessary service calls, and save you the cost of a service call if
the problem is not due to the product itself. If you have checked the “Basic
Troubleshooting” section and still need help, it is available as follows:
You can find the name of your local Authorized Service Provider by visiting
our web site at www.friedrich.com.

If you require further assistance
You can call the Customer Support Call Center at 1-800-541-6645.
Before calling, please make sure that you have the complete model and
serial number, and date of purchase of your equipment available. By
providing us with this information, we will be better able to assist you.

Our specialists are able to assist you with:
Specifications and Features of our equipment.
Referrals to dealers, and distributors.
Use and Care Information.
Recommended maintenance procedures.
Installation information.
Referrals to Authorized Service Providers and Parts depots.

Available Accessories
DC-2 Drain Kit – Part No. 01900235
In some installations, excess condensate water caused by extremely humid
conditions, may result in an undesirable water drip such as on a patio or
over an entryway. MODEL DC-2 DRAIN KIT (Part No. 01900-235) can be
installed to drain excess condensation to an alternate location.

Carbon Filter Kits
The kits vary depending on the chassis size (small, medium, large). Each
kit contains three (3) filters.
WCFS – Carbon filter kit for small chassis models.
WCFM – Carbon filter kit for medium chassis models.
WCFL – Carbon filter kit for large chassis models.

Remote Wall Thermostats
RT4 – Digital wall thermostat hard wired with single speed fan.
RT5 – Digital wall thermostat hard wired with a digital display, two fan speed
selection, filter check light, temperature limiting, status indicator light, room
temperature offset, backlight and battery backup.

Window Installation Kits (Standard in Kühl
Models without Heat)
KWIKS – For all ES and YS models.
KWIKM – For all EM and YM models.
KWIKL – For all EL and YL models.
See www.friedrich.com for additional accessories for your unit.

ROOM AIR CONDITIONER UNIT PERFORMANCE TEST DATA SHEET
JOB NAME________________________________ TECHS NAME____________________________________
DATE: _______________ MODEL:_______________ SERIAL:________________
HOW IS ALL OF THE INSTALLATION?
GOOD BAD
YES
NO
____
____
____
____
____

IS A C H AS S IS S E A L G AS K E T IN T A L L E D ?
IS T H E F R E S H/E XA US T A IR V E N T OP E N ?
IS A F R IE DR IC H S L E E V E INS T A L L E D?
IS A F R IE DR IC H O UT DO OR G R IL LE INS T A L L E D?
IS MA IN T E N A NC E B E IN G P E R FO R ME D?
If NO is checked use back of sheet for explanation
E L E C T R IC A L :
LINE VOLTAGE (STATIC)
START UP VOLTAGE
AMPERAGE DRAW
AMPERAGE DRAW
C O MP R E S S O R
LOCKED ROTOR AMPS
AMPERAGE DRAW

--------------------------------

____
____
____
____
____

VOLTS
VOLTS
AMPS (COOL)
AMPS (HEAT)

--------- AMPS
--------- AMPS

IN DO O R T E MP E R AT U R E S :
INDOOR AMBIENT TEMPERATURE
RELATIVE HUMIDITY (RH) INDOOR

-------- F
-------- %

DISCHARGE AIR TEMPERATURE (INDOOR)
RETURN AIR TEMPERATURE (INDOOR)

C OO L
HE A T
---------- F --------- F
---------- F --------- F

O U T DO O R T E MP E R A T U R E :
OUTDOOR AMBIENT TEMPERATURE
RH OUTDOOR

--------- F
--------- %

DISCHARGE AIR TEMPERATURE (OUTDOOR)
INTAKE AIR TEMPERATURE (OUTDOOR)

--------- F ---------- F
--------- F ---------- F

APPLICATION USE ------------------------- ROOM (RESIDENTIAL OR COMMERCIAL)
COOLING OR HEATING

AREA W ---------- X L ----------- X H ----------- = SQ/CU/FT ------------

T his is a genera l guide. plea s e c ons ult ma nua l J or M.

This is a general guide.
Please consult manual J or M for exact load calculations.

ERROR CODES AND ALARM STATUS
Error
Code

Maintenance
ICON

Flash

Outdoor Coil Temperature Sensor is
Open or Shorted

Flash

Outdoor Coil > (grater than) 175 F

Flash

Log Only

Flash

Discharge Air > (greater than) 185 F

Shutdown heat pump and electric heater. Run high fan speed until temp is
100°F. Resume operation. Third occurance in 1 hour locks unit out.

Flash

Prerssure Limit Switch Open

If unit is cooling or heat pump on,shut down compressor. Run high fan until
switch closes. Resume operation. Third occurance in 1 hour locks unit out.

Problem
Front Panel Button Stuck For More
Than 20 Seconds
Input Voltage Out of Specification (103
- 127 / 187 - 253)
Indoor Temperature Sensor is Open or
Shorted
Indoor Coil Temperature Sensor is
Open or Shorted

Control Board's Action
Continue to monitor for "OPEN" (Unstuck) switch. Do not process switch
input. ENSURE FRONT COVER DOES NOT DEPRESS BUTTONS
Stop.Open all relays until voltage is back within specs. Resume operation
Set temp to 75°F in COOLING or 68°F in HEATING. Unit continues to
operate
Control Board sets temp to 40°F. Override sensor. Unit Continues to
operate.
Sets temp to 20°F. Override sensor. Continue operation. Use Elec Heat if
available for HEATING. If not available use HEAT PUMP if outdoor temp
allows.
Shut down for 5 min. Resume operation for 3 min. Continues to monitor. If
test fails 3 times, the severity is increased and the unit operation is locked
out.
Turn compressor off. Run High Fan speed. When coil temp reachs 45°F
resume operation after lockout time.

Indoor Coil < (less than) 30 F for 2
consecutive minutes
Unit Cycles > (grater than) 9 Times per
Continue operation. Continue to monitor. Take no action. Log Only.
hour
Unit Cycles < (less than) 3 Times per
Continue operation. Continue to monitor. Take no action. Log Only.
Hour
Only used if Electric Heat is available. Run High Speed and Electric heat
until room temp reaches 46°F. Display "FRZ" during operation. Logged
Room Freeze Protection
Only
Severity 4 error is. Unit operates based on standard input mapping.
WallStat Problem or Connection Issue
Severity 2 error opens all relays. Unit will not operate.

Flash

Discharge Air Temperature Sensor is
Open or Shorted

OFF, Log Only

Frost Protection (for Heat Pump Only
Unit- YS10M10)

Unit will run active defrost for a minimum of 6 minutes when Heat Pump
run time is greater than 60 minutes and outdoor coil temp is 26 F or less.

Flash

Outdoor Air Temperature Sensor is
Open or Shorted

Continue with normal operation. Continue to monitor sensor.

14
15
16
17
18
19
20
21
22

Override Sensor. Set temp to 75°F. Continue to monitor. Set error code 14
ON.
If indoor coil temp < (Lesser than) ambient temp for 3 minutes. Unit uses
Solid On
Heat Pump Error
electric heat to satisfy heating demand.
Ambient temp < (less than) 0°F and ambient temp > (greater than) 130°F.
Flash
Temperature Beyond Operating Limits
Set error code 16 ON. When cleared return unit to normal.
Equipment Doesn't Meet Minimum
Flash
Must have compressor enabled and at least 2 fan speeds
Configuration
Unit shuts down. Inputs via front panel or t-stat are ignored. Qualified
Flash
Special Test 1 Severity Level 1
Technical Service required URGENT
Flash
Special Test 2 Severity Level 2
Unit operates. Qualified Technical Service required
Error is Logged Only. Unit operates. Severity 3 keeps unit running.
Solid On
Special Test 3 Severity Level 3
Attention is needed
Error is Logged Only. Unit operates. Severity 4 keeps unit running.
OFF, Log Only Special Test 4 Severity Level 4
Outdoor Coil Temperature < 30 F for 2 Unit will use electric heat to satisfy heating demands until temp > 45°F.
OFF, Log Only
consecutive Minutes
Unit must be a Heat Pump.

Key Sequence

Action

Enter Maintenance Menu
Press SYSTEM + SCHEDULE + BACK + DISPLAY/ENTER for 6 secs or until double beep sounds()
Reset Error Codes & Error History Press + for 3 secs or until double beep sounds ( )

TROUBLESHOOTING TIPS
NOTE: To more accurately identify the problem, first check for current maintenance
alerts and their history.
Problem

Possible Cause
The unit is turned to the off position,

Unit does not operate.

Turn the unit to the on position and raise or
lower temperature setting (as appropriate) to
call for operation.

The LCDI power cord is unplugged.

Plug into a properly grounded 3 prong
receptacle. See “Electrical Rating Tables” on
pg. 6 for the proper receptacle type for your
unit.

The LCDI power cord has tripped
(Reset button has popped out).

Press and release RESET (listen for click;
Reset button latches and remains in) to resume
operation.

The circuit breaker has tripped or
the supply circuit fuse has blown.

Reset the circuit breaker, or replace the fuse as
applicable. If the problem continues, contact a
licensed electrician.

There has been a local power
failure.

The unit will resume normal operation once
power has been restored.

Other appliances are being used on
the same circuit.

The unit requires a dedicated outlet circuit, not
shared with other appliances.

An extension cord is being used.

Do NOT use an extension cord with this or any
other air conditioner.

The circuit breaker or time-delay
fuse is not of the proper rating.

Replace with a circuit breaker or time-delay
fuse of the proper rating. See “Electrical
Rating Tables” on pg. 6 for the proper circuit
breaker/fuse rating for your unit. If the problem
continues, contact a licensed electrician.

The LCDI power cord can trip
(Reset button pops out) due to
disturbances on your power supply
line.

Press and release RESET (listen for click;
Reset button latches and remains in) to resume
normal operation.

Electrical overload, overheating, or
cord pinching can trip (Reset button
pops out) the LCDI power cord.

Once the problem has been determined and
corrected, press and release RESET (listen for
click; Reset button latches and remains in) to
resume normal operation.

Unit Trips Circuit Breaker or
Blows Fuses.

LCDI Power Cord Trips (Reset
Button Pops Out).

Possible Solution

NOTE:

A damaged power supply cord must be replaced with a new power supply cord
obtained from the product manufacturer and must not be repaired.

The return/discharge air grille is
blocked.

Ensure that the return and/or discharge air
paths are not blocked by curtains, blinds,
furniture, etc.

Windows or doors to the outside are
open.

Ensure that all windows and doors are closed.

The temperature is not set at a cool
enough/warm enough setting.

Adjust the Temperature control to a cooler or
warmer setting as necessary.

Unit Does Not Cool/Heat
remove obstruction.
On And Off Too Frequently.

The indoor coil or outdoor coil is
dirty or obstructed.

Clean the coils, (See Routine Maintenance), or
remove obstruction.

There is excessive heat or moisture
(cooking, showers, etc.) in the room.

Be sure to use exhaust vent fans while cooking
or bathing and, if possible, try not to use heat
producing appliances during the hottest part of
the day.

The temperature of the room you
are trying to cool is extremely hot.

Allow additional time for the air conditioner to
cool off a very hot room.

TROUBLESHOOTING TIPS (Continued)
Problem

Possible Cause
The outside temperature is below
60° F (16° C).

Do not try to operate your air conditioner in the
cooling mode when the outside temperature
is below 60° F (16° C). The unit will not cool
properly, and the unit may be damaged.

The digital control is set to fan
cycling mode.

Since the fan does not circulate the room
air continuously at this setting, the room air
does not mix as well and hot (or cold) spots
may result. Using the continuous fan setting
is recommended to obtain optimum comfort
levels.

Unit Does Not Cool/Heat
On And Off Too Frequently
(continued).

cooling capacity to match the heat
gain of the room.

heating capacity to match the heat
loss of the room.

Unit Runs Too Much.

Possible Solution

Check the cooling capacity of your unit to
ensure it is properly sized for the room in which
it is installed. Room air conditioners are not
designed to cool multiple rooms.
Check the heating capacity of your unit. Air
conditioners are sized to meet the cooling load,
and heater size is then selected to meet the
heating load. In extreme northern climates,
room air conditioners may not be able to be
used as a primary source of heat.

This may be due to an excessive
heat load in the room.

If there are heat producing appliances in use
in the room, or if the room is heavily occupied,
the unit will need to run longer to remove the
additional heat.

It may also be due to an improperly
sized unit.

Be sure to use exhaust vent fans while cooking
or bathing and, if possible, try not to use heat
producing appliances during the hottest part of
the day.

This may be normal for higher

your new air conditioner may result in the
unit running longer than you feel it should.
This may be more apparent, if it replaced an

compared to older models.
You may notice that the discharge
air temperature of your new air
conditioner may not seem as cold
as you may be accustomed to from
older units. This does not, however,
indicate a reduction in the cooling
capacity of the unit.

capacity rating (Btu/h) listed on the unit’s rating

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem

Possible Cause
Low voltage

Possible Solution
Check voltage at compressor. 115V & 230V
units will operate at 10% voltage variance

Temperature not set cold enough or Set temperature to lower than ambient position.
room air thermistor inoperative
Test thermistor and replace if inoperative.
Compressor
does not run

Compressor hums but cuts off on
overload

Hard start compressor. Direct test compressor.
If compressor starts, add starting components

Open or shorted compressor
windings

Check for continuity & resistance

Open overload

Test overload protector & replace if inoperative

Open capacitor

Test capacitor & replace if inoperative

Inoperative system button

Test for continuity in all positions. Replace if
inoperative switch or electronic board.

Broken, loose or incorrect wiring

Refer to appropriate wiring diagrams to check
wiring. Correct as needed.

Problem

Fan motor
does not run

Possible Cause
Inoperative system button

Test button & replace user interface if inoperative

Broken, loose or incorrect wiring

Refer to applicable wiring diagram

Open capacitor

Test capacitor & replace if inoperative

Fan speed button defective

Replace user interface if inoperative

Inoperative fan motor

Test fan motor & replace if inoperative (be sure
internal overload has had time to reset)

Possible Cause

Problem

Does not cool or
only cools slightly

Possible Solution

Undersized unit

Refer to industry standard sizing chart

Indoor ambient thermistor open
or shorted

See alarms and replace thermistor if needed.

Dirty filter

Clean as recommended in Owner ’s Manual

Dirty or restricted condenser or
evaporator coil

Use pressure wash or biodegradable cleaning
agent to clean

Poor air circulation

Adjust discharge louvers. Use high fan speed

Fresh air or exhaust air door open

Close doors. Instruct customer on use of this
feature

Low capacity - undercharge

Check for leak & make repair

Compressor not pumping properly

Check amperage draw against nameplate. If
not conclusive, make pressure test

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem

Unit does not run

Possible Cause
Fuse blown or circuit tripped

Replace fuse, reset breaker. If repeats, check
fuse or breaker size. Check for shorts in unit
wiring & components

Power cord not plugged in

Plug it in

System button in “OFF” position

Set correctly

Inoperative system button or open
electronic control board

Test for continuity. Check alarms. Correct
as needed.

Loose or disconnected wiring
control board or other components

Check wiring & connections. Reconnect per
wiring diagram

Problem

Evaporator coil
freezes up

Problem

Possible Cause

Clean as recommended in Owner ’s Manual

Restricted airflow

Check for dirty or obstructed coil. Use
pressure wash or biodegradable cleaning
agent to clean

Inoperative thermistor

Check alarms. Replace as necessary.

Short of refrigerant

De-ice coil & check for leak

Inoperative fan motor

Test fan motor & replace if inoperative

Partially restricted capillary tube

De-ice coil. Replace capillary tube.

Possible Cause

Possible Solution

Excessive heat load

Unit undersized. Test cooling performance &
replace with larger unit if needed. See sizing chart.

Restriction in line

Check for partially iced coil & check
temperature split across coil
Find leak and repair.
Check operation of t-stat. Replace if contacts
remain closed.

Remote wall T-stat incorrectly wired

Refer to appropriate wiring diagram

Thermistor shorted

Replace thermistor or electronic control board

Possible Cause
Compressor relay contacts stuck

Electronic control Temperature set at coldest point
board does not
turn unit off
Incorrect wiring

Possible Solution

Dirty filter

Compressor runs
continually & does Refrigerant leak
not cycle off
Compressor relay contacts stuck

Problem

Possible Solution

Possible Solution
Replace electronic control board
Turn to higher temp. setting to see if unit
cycles off. If not, replace control board.
Refer to appropriate wiring diagrams

Unit undersized for area to be
cooled

Refer to industry standard sizing chart

Defective thermistor

Replace thermistor or electronic control board

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem

Possible Cause
Overload inoperative. Opens too
soon

Check operation of unit. Replace overload if
system operation is satisfactory

Compressor restarted before
system pressures equalized

Control’s default of 3 minutes wait delay timer
inoperative. Replace board.

Compressor runs
Low or fluctuating voltage
for short periods
only. Cycles on
overload
Incorrect wiring

Restricted or low air flow through
condenser coil or evaporator coil

Check for proper fan speed or blocked
coils. Correct as needed.

Compressor running abnormally
hot

Check for kinked discharge line or restricted
condenser. Refrigerant overcharge. Check
amperage, connections.

Possible Cause

Problem

Water leaks into
the room

Possible Solution
Check power supply. Check LCDI plug. Check
wire connections. Check if panel is locked.

Incorrect wiring

Refer to appropriate wiring diagram

Defective thermistor

Replace thermistor or electronic control board

Possible Cause
Poorly installed

Noisy operation

Refer to appropriate wiring diagram
Test capacitor and replace if needed.

No power

Problem

Check voltage with unit operating. Check for
other appliances on circuit. Air conditioner
should be in a dedicated circuit for proper
voltage & fused separately

Shorted or incorrect capacitor

Problem

Unit does not
turn on

Possible Solution

Possible Solution
Refer to Installation Manual for proper
installation

Fan blade striking chassis

Reposition - adjust motor mount

Compressor vibrating

Check that compressor grommets have not
deteriorated. Check that compressor mounting
parts are not missing

Improperly mounted or loose
cabinet parts refrigerant tubes

Check assembly & parts for looseness,
rubbing & rattling pipes, etc.

Possible Cause

Possible Solution

Evaporator drain pan overflowing

Clean obstructed drain trough

Condensation forming underneath
base pan

Evaporator drain pan broken or cracked.
Reseal or replace. No chassis gasket installed.
Install chassis gasket

Poor installation resulting in rain
entering the room

Check installation instructions. Reseal as
required

Condensation on discharge grille
louvers

Dirty evaporator coil. Use pressure wash
or biodegradable cleaning agent to clean.
Environmental phenomena: point supply
louvers upward. Put on high fan.

Chassis gasket not installed

Install gasket, per Installation manual

Downward slope of unit is too
steep inward

Refer to installation manual for proper
installation

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem

Water “spitting”
into room

Problem

Excessive
moisture

Problem

Unit
short cycles

Problem

Prolonged off
cycles

Problem

Outside water
leaks

Possible Cause

Possible Solution

Sublimation:
When unconditioned saturated,
outside air mixes with conditioned
air, condensation forms on the
cooler surfaces

Ensure that foam gaskets are installed in
between window panes & in between the
unit & the sleeve. Also, ensure that fresh
air/exhaust vents (on applicable models) are in
the closed position & are in tact

Downward pitch of installation is
too steep towards back of unit

Follow installation instructions to ensure that
downward pitch of installed unit is no less than
1/4” & no more than 3/8”

Restricted coil or dirty filter

Clean & advise customer of periodic cleaning
& maintenance needs of entire unit

Possible Cause

Possible Solution

Insufficient air circulation thru area
to be air conditioned

Adjust louvers for best possible air circulation

Oversized unit

Operate in “MoneySaver” position

Inadequate vapor barrier in building
structure, particularly floors

Advise customer

Possible Cause

Possible Solution

Defective thermistor

Replace thermistor or electronic control board

Unit oversized

See sizing chart. Correct as needed.

Chassis seal gasket not sealing or
absent causting unit to short cycle

Check gasket. Reposition or replace as
needed

Restricted coil or dirty filter

Clean & advise customer of periodic cleaning
& maintenance needs of entire unit

Possible Cause

Possible Solution

Defective indoor ambient thermistor
or electronic control board

Check alarms. Replace thermistor or electronic
control board

Defective remote wall t-stat

Replace t-stat

Possible Cause

Possible Solution

Evaporator drain pan cracked or
obstructed

Repair, clean or replace as required

Water in compressor area

Detach shroud from pan & coil. Clean &
remove old sealer. Reseal, reinstall & check

Obstructed condenser coil

Use pressure wash or biodegradable cleaning
agent to clean

Fan blade/slinger ring improperly
positioned

Adjust fan blade to 1/2” of condenser coil fin
pack

HEAT / COOL ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS
Problem

Room temperature
uneven
(Heating cycle)

Possible Cause
Bad indoor ambient thermistor

Check error codes. Replace as needed.

Fan speed too low

Set at higher fan speed.

Opened door, windows, etc.

Close doors, windows, etc.

ATSF (room air sampling feature) disabled

Enable ATSF

Problem

Possible Cause
Bad outdoor coil thermistor

Unit will not defrost
(Heat pump
only models)

Possible Solution

Possible Solution
Replace thermistor.
• On heat pumps with electric heat: no action needed
• On model YSM10: do not operate below 32°F/ 0°C

Temperature below 32°F/ 0°C

• If outdoor air temp is higher than freezing, check
reversing valve, electric coil, outdoor thermistor,
refrigerant circuits, etc.
• For proper operation: correct as needed

Problem

Does not heat
adequately

Possible Cause

Possible Solution

Exhaust or fresh air door open

Check if operating properly. Instruct customer on
proper use of control

Dirty filter

Clean as recommended in Owner's Manual

Unit undersized

Check heat rise across coil. If unit operates
efficiently, check if insulation can be added
to attic or walls. If insulation is adequate,
recommend additional unit or larger one

Outdoor coil thermistor or electronic control
board defective

Check alarms (error codes). Replace thermistor
or electronic control board.

Heater hi-limit control cycling on & off

Check for adequate fan air across heater. Check
for open hi-limit control.

Shorted or open supplementary heater

Do ohmmeter check.

Incorrect wiring

Check applicable wiring diagram

HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS
Problem

Unit cools when
heat is called for

Possible Cause
Incorrect wiring

Refer to applicable wiring diagram

Defective solenoid coil

Check for continuity of coil

Reversing valve fails to shift

Block condenser coil & switch unit to cooling.
Allow pressure to build up in system, then
switch to heating. If valve fails to shift, replace
valve.

Inoperative system switch

Check for continuity of system switch

Problem

Cooling adequate,
but heating
insufficient

Action

Possible Cause

Action

Heating capillary tube partially
restricted

Check for partially starved outer coil. Replace
heating capillary tube

Check valve leaking internally

Switch unit several times from heating to
cooling. Check temperature rise across
coil. Refer to specification sheet for correct
temperature rise

Reversing valve failing to shift
completely; bypassing hot gas

Denergize solenoid coil, raise head pressure,
energize solenoid to break loose. If valve fails
to make complete shift, replace valve.

TROUBLESHOOTING CHART - HEAT PUMP

REFRIGERANT SYSTEM DIAGNOSIS - COOLING CYCLE
LOW SUCTION PRESSURE

HIGH SUCTION PRESSURE

Low Load Conditions

LOW HEAD PRESSURE

HIGH HEAD PRESSURE

High Load Conditions

Low Load Conditions

High Load Conditions

Low Air Flow Across
Indoor Coil

High Air Flow Across
Indoor Coil

Refrigerant System
Restriction

Low Air Flow Across
Outdoor Coil

Refrigerant System
Restriction

Reversing Valve not
Fully Seated

Overcharged

Undercharged

Overcharged

Undercharged
in System

Noncondensables (air)

Moisture in System

Defective Compressor

HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS

REFRIGERANT SYSTEM DIAGNOSIS - HEATING CYCLE

LOW SUCTION PRESSURE

HIGH SUCTION PRESSURE

LOW HEAD PRESSURE

HIGH HEAD PRESSURE

Low Airflow
Across Outdoor Coil

Outdoor Ambient Too High
for Operation in Heating

Refrigerant System
Restriction

Outdoor Ambient Too High
For Operation In Heating

Refrigerant System
Restriction

Reversing Valve not
Fully Seated

Low Airflow Across
Indoor Coil

Undercharged

Overcharged

Undercharged

Overcharged

Moisture in System

Defective Compressor

Noncondensables (air)
in System

ELECTRICAL TROUBLESHOOTING CHART - HEAT PUMP
HEAT PUMP
SYSTEM COOLS WHEN
HEATING IS DESIRED.

Is Line Voltage
Present at the Solenoid
YES
Is the Solenoid Coil Good?

Is the Selector Switch
Set for Heat?

Replace the Solenoid Coil

YES
Reversing Valve Stuck

Replace the Reversing Valve

TROUBLESHOOTING TOUCH TEST CHART: TO SERVICE REVERSING VALVES

Normal Cooling
Normal Heating

Hot
Hot

RIGHT Pilot

NOTES:

RIGHT
PilotTube
Capillary
Capillary Tube

LEFT Pilot

LEFTCapillary
Pilot Tube
Capillary Tube

Tube to OUTSIDE

COIL
Tube to OUTSIDE
COIL

SUCTION TUBE

to INSIDE
Tube toTube
INSIDE
COILCOIL

SUCTION
TUBE to
to Compressor
Compressor

DISCHARGE
TUBE
from Compressor
from Compressor

VALVE
OPERATING
CONDITION

DISCHARGE TUBE

NORMAL FUNCTION OF VALVE

* TEMPERATURE OF VALVE BODY
** WARMER THAN VALVE BODY

POSSIBLE CAUSES

CORRECTIONS

Cool

Cool
as (2)

Hot
as (1)

*TVB

TVB

Cool

Hot
as (1)

Cool
as (2)

*TVB

TVB

MALFUNCTION OF VALVE
No voltage to coil.

Repair electrical circuit.

Check Electrical circuit and coil
Defective coil.

Replace coil.

Low charge.

Repair leak, recharge system.

Pressure differential too high.

Recheck system.

Check refrigeration charge

Valve will not
shift from cool
to heat.

Hot

Apparent
leap in heating.

*TVB

Hot

Hot,
as (1)

Hot

Cool

Cool,
as (2)

Hot,
as (1)

Hot

Warm

Cool

Cool,
as (2)

Hot,
as (1)

*TVB

Warm

Hot

Warm

Hot

*TVB

Hot

*TVB

Hot

Warm

Hot

*TVB

Hot

Clogged pilot tubes.

Raise head pressure, operate solenoid to
free. If still no shift, replace valve.

Both ports of pilot open. (Back seat port
did not close).

Raise head pressure, operate solenoid
to free
partially clogged port. If still no shift,
replace
valve.

Defective Compressor.

Replace compressor

Not enough pressure differential at start
of stroke or not enough fl ow to maintain
pressure differential.

Check unit for correct operating pressures
and charge. Raise head pressure. If no
shift, use valve with smaller port.

Body damage.

Replace valve

Both ports of pilot open.

Raise head pressure, operate solenoid. If
no shift, use valve with smaller ports.

Body damage.

Replace valve

Valve hung up at mid-stroke. Pumping
volume of compressor not suffi cient to
maintain reversal.

Raise head pressure, operate solenoid. If
no shift, use valve with smaller ports.

Both ports of pilot open.

Raise head pressure, operate solenoid.
If no
shift, replace valve.

Hot

Cool

Hot,
as (1)

Cool,
as (2)

*TVB

Piston needle on end of slide leaking.

Operate valve several times, then recheck.
If excessive leak, replace valve.

Hot

Cool

Hot,
as (1)

Cool,
**WVB
as (2)

**WVB

Pilot needle and piston needle leaking.

Operate valve several times, then recheck.
If excessive leak, replace valve.

Hot

Cool

Hot,
as (1)

Cool,
as (2)

Pressure differential too high.

Stop unit. Will reverse during equalization
period. Recheck system

Clogged pilot tube.

Raise head pressure, operate solenoid to
free dirt. If still no shift, replace valve.

Dirt in bleeder hole.

Raise head pressure, operate solenoid.
Remove valve and wash out. Check on air
before reinstalling, if no movement, replace
valve. Add strainer to discharge tube.
Mount valve horizontally.

*TVB

Hot

Stop unit. After pressures equalize, restart
with solenoid energized. If valve shifts,
reattempt with compressor running. If still
no shift, replace valve.

Hot

Piston cup leak

Hot

*TVB

Cool

Hot,
as (1)

Cool,
as (2)

Hot

Cool

Hot,
as (1)

Cool,
as (2)

Hot

*TVB

Piston cup leak.

Stop unit. After pressures equalize, restart
with solenoid deenergized. If valve shifts,
reattempt with compressor running. If it
still will not reverse while running, replace
the valve.

Hot

Cool

Hot,
as (1)

Cool,
as (2)

Hot

Defective pilot.

Replace valve.

Warm

Cool

Warm,
as (1)

Cool,
as (2)

Warm

*TVB

Defective compressor.

Replace compressor

Hot

Will not shift
from heat to
cool.

Hot,
as (1)

Cool,
as (2)

Starts to shift
but does not
complete
reversal.

Cool,
as (2)

Cool

Hot

Valve will not
shift from cool
to heat.

Cool

Deenergize solenoid, raise head pressure,
reenergize solenoid to break dirt loose.
If unsuccessful, remove valve, wash
Pilot valve okay. Dirt in one bleeder hole.
out. Check on air before installing. If no
movement, replace valve, add strainer to
discharge tube, mount valve horizontally.

Hot

*TVB

ELECTRONIC CONTROL BOARD COMPONENTS IDENTIFICATION
Front

Back

Reversing Valve
Battery Compartment

Max Speed

High Speed
Med Speed
Low Speed

DISCHARGE

Transformer
115/230 Volts

User Interface
connector

T-stat Terminals

Transformer voltage
Selector Switch
115/230 Volts

Sample board for Kuhl+ unit

REMOTE WALL THERMOSTAT WIRING DIAGRAMS
LEGEND FOR T-STAT WIRING HARNESS
C
Common Terminal
GH
Call for High Fan
GL
Call for Low Fan
B
Reversing Valve
Y
Coil for Cooling
W
Call for Heat
R
24 VAC Power From Unit
RT5 - Two Speeds Fan T-Stat - Field Provided
-- -- -- Field Wiring

COOL W/O ELECTRIC HEAT

COOL WITH ELECTRIC HEAT

Electronic Control Board
24 VAC Connections

C GH GL

Jumper
Wire

GH GL O

Jumper
Wire

W RC RH C

GH GL O

RT5 Thermostat

W RC RH C

RT5 Thermostat

HEAT PUMP ONLY AND
HEAT PUMP WITH ELECTRIC HEAT
Electronic Control Board
24 VAC Connections
C GH GL

Jumper
Wire

GH GL O

W RC RH C

KUHL
ELECTRONIC CONTROL
COOL ONLY MODELS
SS08M10A, SS10M10A, SS12M10A, SS14M10A
SS12M30A, SS15M30A
SM18M30A, SM21M30A, SM24M30A
WIRING DIAGRAM
COMPRESSOR
OLP

BLUE
RED
BLACK

C
S

UI HOLDER ELECTRONICS ASY

BLACK

F4
RELAY

BLUE

F3
RELAY

ORANGE
RED

OD AIR SENSOR
OD COIL SENSOR
ID COIL SENSOR

F2
RELAY
F1
RELAY
DCHRG
AIR
SENSOR

TO
DISPLAY

L2 or ACN
AMBIENT
AIR SENSOR

COMP
RELAY
BLACK
L1

WHITE

CAPACITOR
BROWN

COM

N
FA

BLUE

CAPACITOR
GREEN BRACKET
TO CHASSIS

TO INNERWALL/
MOTOR MOUNT

GREEN

RED

GREEN
OR GREEN/YELLOW

BLACK
WHITE

WHITE

SUPPLY CORD

TO CAPACITOR
BRACKET

MOTOR

SCHEMATIC

MAX

NEUTRAL (115 V)

USER INTERFACE

(230/208 V)

HIGH

FAN MTR

OLP
MEDIUM

LOW

OLP
COMPRESSOR
5

COM

CAP

L2 OR N

FAN

COMPRESSOR

COMP

ELECTRONIC CONTROL

HERM

COM

CAP

LEGEND
CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
OLP
- OVERLOAD PROTECTOR
- USER INTERFACE
UI
TF
- THERMAL FUSE
HL

- HEATER LIMIT FUSE

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT

PART NO.
92170000

REV.
04

KUHL
ELECTRONIC CONTROL
COOL ONLY MODELS
SL28M30A, SL36M30A
WIRING DIAGRAM

COMPRESSOR

UI HOLDER ELECTRONICS ASY

OLP

BLUE
RED
BLACK

C
S

OD AIR SENSOR
OD COIL SENSOR
ID COIL SENSOR
F4
RELAY
BLACK
BLUE

F3
RELAY
F2
RELAY

RED

F1
RELAY
DCHRG
AIR
SENSOR

SOLID STATE RELAY

BLACK

L2 or ACN

WHITE

AMBIENT
AIR SENSOR

SSR
1

BLUE

TO
DISPLAY

COMP
RELAY

BLACK

WHITE

CAPACITOR
COM

BROWN

N
FA

SUPPLY CORD

TO CAPACITOR
BRACKET

GREEN

BLUE

RM
HE

RED
CAPACITOR
GREEN BRACKET
TO CHASSIS

GREEN
OR GREEN/YELLOW

BLACK
WHITE

WHITE

MOTOR

TO INNERWALL/
MOTOR MOUNT

SCHEMATIC
NEUTRAL (115 V)

USER INTERFACE

(230/208 V)

HIGH

FAN MTR

OLP
MEDIUM

LOW

CAP

L2 OR N

OLP
COMPRESSOR

COM

FAN

COMPRESSOR

COMP

ELECTRONIC CONTROL

HERM

COM

CAP

LEGEND
CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
- OVERLOAD PROTECTOR
OLP
UI
- USER INTERFACE
TF
- THERMAL FUSE
HL

- HEATER LIMIT FUSE

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT

PART NO.
92170001

REV.
04

KUHL+
ELECTRONIC CONTROL
COOL WITH ELECTRIC HEAT MODELS
ES12M33A, ES15M33A
EM18M34A, EM24M34A
WIRING DIAGRAM
COMPRESSOR
OLP

BLUE
RED
BLACK

C
S

UI HOLDER ELECTRONICS ASY

OD AIR SENSOR
OD COIL SENSOR
ID COIL SENSOR

RV
RELAY
FAN 4
RELAY

HEATER
ORANGE

BLACK

FAN 3
RELAY

BLUE

FAN 2
RELAY

ORANGE

RED

FAN 1
RELAY
HEAT
RELAY

DCHRG
TO
AIR
SENSOR DISPLAY
L2 or ACN

HEAT
RELAY

BLACK

AMBIENT
AIR SENSOR

COMP
RELAY

WHITE

CAPACITOR
BROWN

COM

N
FA

BLUE

R
HE

CAPACITOR
GREEN BRACKET
TO CHASSIS

TO INNERWALL/
MOTOR MOUNT

GREEN

RED

GREEN
OR GREEN/YELLOW

BLACK
RED

WHITE

SUPPLY CORD

TO CAPACITOR
BRACKET

MOTOR

SCHEMATIC
USER INTERFACE

HIGH
3

(230/208 V)

MEDIUM

FAN MTR

OLP
LOW

S
ELECTRIC HEAT

6
7

EH1

HL
ELECTRIC HEAT

CAP
HTR

EH2

L2 OR N

OLP
COMPRESSOR
L1

COM

FAN

COMPRESSOR

COMP

HERM

COM

CAP

ELECTRONIC CONTROL

LEGEND
CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
- OVERLOAD PROTECTOR
OLP
UI
- USER INTERFACE
THERMAL FUSE
TF
HL

- HEATER LIMIT FUSE

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT
PART NO.
92170002

REV.
04

KUHL+
ELECTRONIC CONTROL
COOL WITH ELECTRIC HEAT MODEL
EL36M35A
WIR ING DIAG R AM
C OMP R E S S OR
OL P

B LU E
RED
B LAC K

C
S

UI HOLDE R E LE C T R O NIC S AS Y

O UTDO OR A IR S E NS OR

RV
R E LAY

S OL ID S T AT E R E LAY

OUT DOOR C OIL S E NS OR
IN DOOR C OIL S E NS OR

F AN 4
R E L AY

SSR

F AN 3
R E L AY

B LAC K
B LUE

HE AT E R
OR ANG E

F AN 2
R E L AY

RED
F AN 1
R E LAY

RED

DS C HR G
AIR
S E NS OR

HE AT
R E LAY

RED

S O L ID S T AT E R E LAY

B LU E

WH IT E

B LAC K

AMB IE NT
AIR S E NS OR

C OMP
R E LAY

SSR

TO
DIS P LAY

L2 or AC N

HE AT
R E LAY

B LU E

B LAC K

B LAC K
B LAC K

GR E EN
OR G R E E N/Y E LLOW

W HIT E
W HIT E

WHIT E

C AP AC IT O R
B R OW N

C OM

C AP AC IT O R
G R E E N B R AC K E T
T O C H AS S IS

GR E EN

RED

B LUE

S UP P LY C OR D

T O C AP AC IT OR
B R AC K E T

MO T O R

T O INNE R W ALL /
MOT OR MOUNT

S C HE MAT IC
NE UT R AL (115 V )
US E R INT E R F AC E

HIG H

(230/208 V )

R
ME DIUM

F AN MT R
L OW

C AP

E L E C T R IC HE AT

6
E H1

C OM

F AN

HT R

E L E C T R IC HE AT

O LP
C OMP R E S S OR

C OMP

C OMP R E S S O R

C OM

HE R M

C AP

LE G E ND
C AP
C OMP R
MT R
O LP
UI
TF

- C AP AC IT O R
- C O MP R E S S OR
- F AN MO T O R
- OV E R L OAD P R OT E C T OR
- US E R INT E R F AC E
- T HE R MAL F US E

- HE AT E R LIMIT F US E

- T HE R MIS T E R
- C O MB INAT ION T E R MINAL
- G R OUNDE D LE AD S Y MB OL
- INS ULAT O R

HT R

- HE AT E R E LE ME NT

P AR T NO .
92170007

R E V.
00

KUHL+
ELECTRONIC CONTROL
HEAT PUMP ONLY MODEL
YS10M10A
WIRING DIAGRAM
COMPRESSOR

UI HOLDER ELECTRONICS ASY

COIL, SOLENOID
OLP

BLUE
RED
BLACK

C
S

BLUE

OD AIR SENSOR
OD COIL SENSOR
ID COIL SENSOR

RV
RELAY

BLACK

F4
RELAY
F3
RELAY

BLACK
BLUE
ORANGE

F2
RELAY
F1
RELAY
DCHRG
AIR
SENSOR

HEAT
RELAY

TO
DISPLAY

L2 or ACN

HEAT
RELAY

BLACK

AMBIENT
AIR SENSOR

COMP
RELAY

RED

WHITE

CAPACITOR
BROWN

COM

BLUE

RM
HE

CAPACITOR
GREEN BRACKET
TO CHASSIS

TO INNERWALL/
MOTOR MOUNT

GREEN

RED

GREEN
OR GREEN/YELLOW

BLACK
WHITE

SUPPLY CORD

TO CAPACITOR
BRACKET

MOTOR

SCHEMATIC

HIGH

NEUTRAL (115 V)

USER INTERFACE

MEDIUM

OLP

FAN MTR

LOW

S
REVERSE CYCLE

(230/208 V)

COM

FAN

CAP

6
HP

L2 OR N

OLP
COMPRESSOR

COMPRESSOR

COMP

ELECTRONIC CONTROL

HERM

COM

CAP

LEGEND
CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
OLP
- OVERLOAD PROTECTOR
- USER INTERFACE
UI
- THERMAL FUSE
TF
HL

- HEATER LIMIT FUSE

- REVERSING VALVE
T

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT

PART NO.
92170003

REV.
04

KUHL+
ELECTRONIC CONTROL
HEAT PUMP WITH ELECTRIC HEAT MODELS
YS12M33A, YM18M34A
WIRING DIAGRAM
COMPRESSOR

UI HOLDER ELECTRONICS ASY

COIL, SOLENOID
OLP

BLUE
RED
BLACK

C
S

BLUE

OD AIR SENSOR
OD COIL SENSOR
ID COIL SENSOR

RV
RELAY

BLACK

FAN 4
RELAY

BLACK
BLUE

HEATER
ORANGE

ORANGE

RED

FAN 3
RELAY
FAN 2
RELAY
FAN 1
RELAY

DCHRG
AIR
SENSOR

HEAT
RELAY

TO
DISPLAY

L2 or ACN

HEAT
RELAY

BLACK

AMBIENT
AIR SENSOR

COMP
RELAY

L1
BLACK
WHITE

GREEN
OR GREEN/YELLOW

RED

WHITE

CAPACITOR
BROWN

COM

N
FA

BLUE

CAPACITOR
GREEN BRACKET
TO CHASSIS

TO INNERWALL/
MOTOR MOUNT

GREEN

RED

SUPPLY CORD

TO CAPACITOR
BRACKET

MOTOR

SCHEMATIC
NEUTRAL (115 V)
USER INTERFACE

HIGH

MEDIUM

OLP

FAN MTR

LOW

COM

FAN

CAP

ELECTRIC HEAT

6
EH1
7

HTR

EH2

L2
8

ELECTRIC HEAT

REVERSING CYCLE

OLP

RV
COMPRESSOR

(230/208 V)

COMP

COMPRESSOR

ELECTRONIC CONTROL

COM

HERM

CAP

LEGEND
CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
- OVERLOAD PROTECTOR
OLP
UI
- USER INTERFACE
TF
- THERMAL FUSE
HL

- HEATER LIMIT FUSE

- REVERSING VALVE
T

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT

PART NO.
92170004

REV.
04

KUHL+
ELECTRONIC CONTROL
HEAT PUMP WITH ELECTRIC HEAT MODEL
YL24M35A
WIRING DIAGRAM
COMPRESSOR
OLP

BLUE
RED
BLACK

C
S

UI HOLDER ELECTRONICS ASY

OUTDOOR AIR SENSOR

RV
RELAY

SOLID STATE RELAY
4

SSR
1

HEATER

OUTDOOR COIL SENSOR
INDOOR COIL SENSOR

FAN 4
RELAY

BLACK
3

FAN 3
RELAY

BLUE

ORANGE

FAN 2
RELAY

RED

FAN 1
RELAY

RED

DSCHRG
AIR
SENSOR

HEAT
RELAY

RED

SOLID STATE RELAY
BLACK

BLUE

WHITE

BLACK

AMBIENT
AIR SENSOR

COMP
RELAY

SSR
YELLOW

TO
DISPLAY

L2 or ACN

HEAT
RELAY

BLACK
WHITE

WHITE

GREEN
OR GREEN/YELLOW

BLACK

CAPACITOR
BROWN

COM

BLUE

FA
N

RM
HE

CAPACITOR
GREEN BRACKET
TO CHASSIS

TO INNERWALL/
MOTOR MOUNT

GREEN

RED

SUPPLY CORD

TO CAPACITOR
BRACKET

MOTOR

SCHEMATIC

NEUTRAL (115 V)

USER INTERFACE

HIGH

(230/208 V)

MEDIUM

FAN MTR
LOW

CAP

ELECTRIC HEAT

6
EH1

HTR

ELECTRIC HEAT

L2
7

REVERSING CYCLE

OLP

RV
COMPRESSOR

5
L1
ELECTRONIC CONTROL

COM

FAN

COMP

COMPRESSOR

COM

HERM

CAP

LEGEND

X = CLOSED

SWITCH LOGIC O = OPEN
CIRCUIT

SWITCH POSITION
OFF
HI COOL
MED COOL
LOW COOL
HI HEAT (HP)
MED HEAT (HP)
LOW HEAT (HP)
HI HEAT (EH)
MED HEAT (EH)
LOW HEAT (EH)
HI FAN
MED FAN
LOW FAN

1
O
O
O
X
O
0
X
O
O
X
O
O
X

2
O
O
X
O
O
X
O
O
X
O
O
X
O

3
O
X
O
O
X
O
O
X
O
O
X
O
O

4
O
O
O
O
O
O
O
O
O
O
O
O
O

5
O
X
X
X
X
X
X
O
O
O
O
O
O

6
O
O
O
O
O
O
O
X
X
X
O
O
O

7
O
O
O
O
X
X
X
O
O
O
O
O
O

CAP
- CAPACITOR
COMPR - COMPRESSOR
- FAN MOTOR
MTR
- OVERLOAD PROTECTOR
OLP
- USER INTERFACE
UI
TF
- THERMAL FUSE
HL

- THERMISTER
- COMBINATION TERMINAL
- GROUNDED LEAD SYMBOL
- INSULATOR

HTR

- HEATER ELEMENT

- HEATER LIMIT FUSE

PART NO.
92170008

REV.
00

THERMISTORS’ RESISTANCE VALUES
(This Table Applies to All Thermistors)
TEMP
F
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
31
32
33
34
35
36
37
38
39
40
45
50
55
60
65
66
67
68
69
70
71
72
73
74
75
76

77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
105
110
115
120

INDOOR AIR SENSOR
RESISTENCE (K Ohms)
MIN
CENTR
MAX
210.889
225.548
240.224
178.952
190.889
202.825
151.591
161.325
171.059
128.434
136.363
144.292
108.886
115.340
121.794
92.411
97.662
102.912
78.541
82.812
87.083
66.866
70.339
73.812
57.039
59.864
62.688
48.763
51.060
53.357
41.786
43.654
45.523
35.896
37.415
38.934
34.832
36.290
37.747
33.803
35.202
36.601
32.808
34.150
35.492
31.846
33.133
34.421
30.916
32.151
33.386
30.016
31.200
32.385
29.144
30.281
31.418
28.319
29.425
30.534
27.486
28.532
29.579
26.697
27.701
28.704
23.116
23.931
24.745
20.071
20.731
21.391
17.474
18.008
18.542
15.253
15.684
16.115
13.351
13.697
14.043
13.004
13.335
13.666
12.668
12.984
13.301
12.341
12.644
12.947
12.024
12.313
12.603
11.716
11.993
12.269
11.418
11.682
11.946
11.128
11.380
11.633
10.846
11.088
11.329
10.574
10.804
11.034
10.308
10.528
10.748
10.051
10.260
10.469
9.800
9.550
9.306
9.070
8.841
8.618
8.402
8.192
7.987
7.789
7.596
7.409
7.227
7.050
6.878
6.711
6.548
6.390
6.237
6.087
5.942
5.800
5.663
5.529
4.912
4.371
3.898
3.482

10.000
9.748
9.503
9.265
9.033
8.809
8.591
8.379
8.172
7.972
7.778
7.589
7.405
7.226
7.052
6.883
6.718
6.558
6.403
6.252
6.105
5.961
5.822
5.686
5.060
4.511
4.030
3.606

10.200
9.945
9.699
9.459
9.226
9.000
8.780
8.566
8.358
8.155
7.959
7.768
7.583
7.402
7.226
7.055
6.889
6.727
6.569
6.417
6.268
6.122
5.981
5.844
5.208
4.651
4.161
3.730

RESISTANCE
TOLERANCE %
MIN
MAX
6.50
6.51
6.25
6.25
6.03
6.03
5.81
5.81
5.60
5.60
5.38
5.38
5.16
5.16
4.94
4.94
4.72
4.72
4.50
4.50
4.28
4.28
4.06
4.06
4.02
4.02
3.97
3.97
3.93
3.93
3.89
3.89
3.84
3.84
3.80
3.80
3.75
3.75
3.76
3.77
3.67
3.67
3.62
3.62
3.40
3.40
3.18
3.18
2.96
2.96
2.75
2.75
2.53
2.53
2.48
2.48
2.44
2.44
2.39
2.39
2.35
2.35
2.31
2.31
2.26
2.26
2.22
2.22
2.18
2.18
2.13
2.13
2.09
2.09
2.04
2.04
2.00
2.03
2.07
2.10
2.13
2.17
2.20
2.23
2.27
2.30
2.33
2.37
2.40
2.43
2.47
2.50
2.53
2.57
2.60
2.63
2.67
2.70
2.73
2.77
2.93
3.10
3.27
3.43

2.00
2.03
2.07
2.10
2.13
2.17
2.20
2.23
2.27
2.30
2.33
2.37
2.40
2.43
2.47
2.50
2.53
2.57
2.60
2.63
2.67
2.70
2.73
2.77
2.93
3.10
3.27
3.43

Kühl Remote Control

Replacement Remote Control Configuration Instructions
For Use with Kühl (cool only models) and Kühl + (cool & heat models)
Contents:
• Remote Control with Holder
• (2) AAA-batteries
• Instruction Sheet

ATTENTION! – You May Need to Configure The Replacement Remote Control
Please read instructions completely before attempting configuration of the Remote Control. Failure to
do so could result in the Remote Control not being able to operate the Air Conditioning Unit properly.
Step 1. A. Locate the Model # of your Air Conditioner.
B. Identify the prefix (First 2 Letters) of your unit’s model #.
C. Look at the chart below and in it, find the prefix of your AC unit’s model #.
D. Note the Option # Code (OPT#) next to it and the required action. The unit’s
display is supposed to show this OPT# Code.
Model Prefix

Option Code

SS, SM
SL
YS, YM, YL, ES, EM, EL

OPT 1
OPT 2
OPT 3

Required Action
None – Remote Control configured for use with air conditioner

Perform Steps 2 - 5
Perform Steps 2 - 5

Step 2.

Point the Remote Control at Air Conditioning Unit and then press the Remote Control’s
POWER Key once to illuminate the Air Conditioning Unit’s display.

Step 3.

Once the display on the Air Conditioning Unit is illuminated, check the Option Code
number (OPT#) shown in the display and ensure it matches the OPT# code for your unit
as per the chart above.
Air Conditioner Unit’s Display (see example below Fig 1)
OPT1
OPT2
OPT3 Displayed example

Figure 1

Kühl Remote Control

Step 4

Checking the Remote Control’s OPT # Code
With the Remote Control’s display illuminated, press and hold the Remote Control’s
SCHEDULE and the FAN SPEED Keys simultaneously for approximately 6 seconds until
the Remote Control displays its current OPT# Code.
If the OPT# Code is different than the AC Unit’s OPT# Code see instructions below:
Remote Control
Remote Control’s OPT# Code (see example below Fig 2)
Figure 2

Using the Remote Control’s S Increase or d Decrease Keys, change the OPT# Code
displayed on the Remote Control to match the OPT # Code shown on the Air
Conditioning Unit’s display (see examples below).
Air Conditioning Unit Display

Step 5.

Remote Control Display

To save the setting in the Remote Control, press and hold the Remote Control SCHEDULE
and FAN SPEED Key simultaneously for approximately 6 seconds until the displayed
configuration number on the Remote Control flashes.
The Remote Control is now configured to work with the air conditioner.

Kühl User Interface Service Kit

Replacement Instructions
For Use with Kühl (cool only models) and Kühl + (cool and heat models)
ATTENTION! - Please read these instructions completely before attempting replacement.
Always unplug the power supply from the power supply receptacle.
Contents:
•
•
•
•

User Interface (UI)
Ribbon Cable
2 – Mounting screws for UI
Instruction Sheet

Step 1.

Disconnect ribbon cable by pulling straight out

Step 2.

Remove 2 –mounting screws securing UI and disconnect ribbon cable

Step 3.

Remove UI and ribbon cable from handle assembly

Step 4.

Install new UI using the 2-screws, route new ribbon cable and reattach ribbon cable to UI
and Main control board

Step 5.

Verify control operation

Ribbon cable connection
Mounting screws

INSTRUCTIONS FOR USING COOLING LOAD ESTIMATE
FORM FOR ROOM AIR CONDITIONERS
(AHAM PUB. NO. RAC-1)
A.

This cooling load estimate form is suitable for estimating the cooling load for comfort air conditioning installations
which do not require specific conditions of inside temperature and humidity.

The form is based on an outside design temperature of 95°F dry bulb and 75°F wet bulb. It can be used for areas
in the continental United States having other outside design temperatures by applying a correction factor for the
particular locality as determined from the map.

The form includes “day” factors for calculating cooling loads in rooms where daytime comfort is desired (such as
living rooms, offices, etc.)

The numbers of the following paragraphs refer to the corresponding numbered item on the form:
1.

Multiply the square feet of window area for each exposure by the applicable factor. The window area is the
area of the wall opening in which the window is installed. For windows shaded by inside shades or venetian
blinds, use the factor for “Inside Shades.” For windows shaded by outside awnings or by both outside awnings and inside shades (or venetian blinds), use the factor for “Outside Awnings.” “Single Glass” includes
all types of single thickness windows, and “Double Glass” includes sealed airspace types, storm windows,
and glass block. Only one number should be entered in the right hand column for Item 1, and this number
should represent only the exposure with the largest load.

Multiply the total square feet of all windows in the room by the applicable factor.

3a.

Multiply the total length (linear feet) of all walls exposed to the outside by the applicable factor. Doors should
be considered as being part of the wall. Outside walls facing due north should be calculated separately from
outside walls facing other directions. Walls which are permanently shaded by adjacent structures should be
considered “North Exposure.” Do not consider trees and shrubbery as providing permanent shading. An
uninsulated frame wall or a masonry wall 8 inches or less in thickness is considered “Light Construction.” An
insulated wall or masonry wall over 8 inches in thickness is considered “Heavy Construction.”

3b.

Multiply the total length (linear feet) of all inside walls between the space to be conditioned and any unconditioned spaces by the given factor. Do not include inside walls which separate other air conditioned rooms.

Multiply the total square feet of roof or ceiling area by the factor given for the type of construction most nearly
describing the particular application (use one line only.)

Multiply the total square feet of floor area by the factor given. Disregard this item if the floor is directly on the
ground or over a basement.

Multiply the number of people who normally occupy the space to be air conditioned by the factor given. Use
a minimum of 2 people.

Determine the total number of watts for light and electrical equipment, except the air conditioner itself, that
will be in use when the room air conditioning is operating. Multiply the total wattage by the factor given.

Multiply the total width (linear feet) of any doors or arches which are continually open to an unconditioned
space by the applicable factor.
NOTE: Where the width of the doors or arches is more than 5 feet, the actual load may exceed the calculated
value. In such cases, both adjoining rooms should be considered as a single large room, and the room air
conditioner unit or units should be selected according to a calculation made on this new basis.

9.
10.

Total the loads estimated for the foregoing 8 items.
Multiply the subtotal obtained in item 9 by the proper correction factor, selected from the map, for the particular
locality. The result is the total estimated design cooling load in BTU per hour.

For best results, a room air conditioner unit or units having a cooling capacity rating (determined in accordance
with the NEMA Standards Publication for Room Air Conditioners, CN 1-1960) as close as possible to the estimated
load should be selected. In general, a greatly oversized unit which would operate intermittently will be much less
satisfactory than one which is slightly undersized and which would operate more nearly continuously.

Intermittent loads such as kitchen and laundry equipment are not included in this form.

COOLING LOAD ESTIMATE FORM
HEAT GAIN FROM

WINDOWS:
Northeast
*
East
Southeast
South
Southwest
West
Northwest
North

FACTORS
DAY

QUANTITY

Heat gain from the sun.
These factors are for single glass
only. For glass block, multiply the
above factors by 0.5; for double
glass or storm windows, multiply the
above factors by 0.8.

WINDOWS: Heat by conduction
(Total of all windows.)
Single glass
Double glass or glass block
WALLS: (Based on linear feet of wall)
a. Outside walls
North Exposure
Other than North exposure
b. Inside Walls (between conditioned and
unconditioned spaces only.)
ROOF OR CEILING: (Use one only)
a. Roof, uninsulated
b. Roof, 1 inch or more insulation
c. Ceiling, occupied space above
d. Ceiling, insulated, with attic space above
e. Ceiling, uninsulated, with attic space above

____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.

BTU/Hr.
(Quantity x Factor)

No
(Area
Inside Outside
Shades* Shades* Awnings* X Factor)
60
Use
20 ____
25
80
only
25 ____
40
75
the
20 ____
30
75
largest
20 ____
35
110
load.
30 ____
45
150
Use
45 ____
65
120
only
35 ____
50
0
one.
0 ____
0

_____
_____

14
7

____sq. ft.
____sq. ft.
Light Construction

Heavy Construction

30
60

20
30

____ ft.
____ ft.

____
____
____
____
____
____
____
____

_____
_____

____sq. ft.

_____

____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.
____sq. ft.

19
8
3
5
12

_____
_____
_____
_____
_____

_____

600

_____

Floor: (Disregard if floor is directly on ground or
over a basement.

____sq. ft.

NUMBER OF PEOPLE

____

LIGHTS AND ELECTRICAL EQUIPMENT IN USE

____watts

DOORS AND ARCHES CONTINUOUSLY
OPENED TO UNCONDITIONED SPACE: (TOTAL
LINEAR FEET OF WIDTH.)

____ft.

300

_____

SUBTOTAL

*****

_____

(Factor from Map) =

____

10. TOTAL COOLING LOAD (BTU per hour to be used
for selection of room air conditioner(s).)
____ Total in Item 9 X ____

HEAT LOAD FORM
The heat load form on the following page may be used by
servicing personnel to determine the heat loss of a conditioned
space and the ambient winter design temperatures in which
the unit will heat the calculated space.
The upper half of the form is for computing the heat loss of
the space to be conditioned. It is necessary only to insert
the proper measurements on the lines provided and multiply
by the given factors, then add this result for the total heat
loss in BTU/Hr./°F.
The BTU/Hr. per °F temperature difference is the 70°F
inside winter designed temperature minus the lowest outdoor
ambient winter temperature of the area where the unit is
installed. This temperature difference is used as the multiplier
when calculating the heat loss.
The graph shows the following:

Left Hand Scale

Unit capacity BTU/Hr. or heat loss
BTU/Hr.

Bottom Scale

Outdoor ambient temperature, base
point.

Heat Pump Model

BTU/Hr. capacity heat pump will
deliver at outdoor temperatures.

Balance Point

Maximum BTU/Hr. heat pump
will deliver at indicated ambient
temperature.

Following is an example using the heat load form:
A space to be conditioned is part of a house geographically
located in an area where the lowest outdoor ambient winter
temperature is 40°F. The calculated heat loss is 184 BTU/
Hr./°F.
Subtract 40°F (lowest outdoor ambient temperature for the
geographical location) from 70°F (inside design temperature
of the unit) for a difference of 30°F. Multiply 184 by 30 for a
5500 BTU/Hr. total heat loss for the calculated space.
On the graph, plot the base point (70°) and a point on the
40°F line where it intersects with the 5500 BTU/Hr. line on
the left scale. Draw a straight line from the base point 70
through the point plotted at 40°F. This is the total heat loss
line.
Knowing that we have a 5500 BTU/Hr. heat loss, and
we expect that our heat pump will maintain a 70°F inside
temperature at 40°F outdoor ambient, we plot the selected
unit capacity BTU/Hr. of the unit between 35° and 60° on the
graph and draw a straight line between these points. Where
the total heat loss line and the unit capacity line intersect,
read down to the outdoor ambient temperature scale and
find that this unit will deliver the required BTU/Hr. capacity
to approximately 30°F.

HEATING LOAD FORM
FRIEDRICH ROOM UNIT HEAT PUMPS
WALLS: (Linear Feet)
2” Insulation
Average
WINDOWS & DOORS (Area, sq. ft.)
Single Glass:
Double Glass:

BTU/HR PER
°F TEMP. DIFFERENCE
Lin. Ft. x 1.6
Lin. Ft. x 2.6

Sq. Ft. x 1.13
Sq. Ft. x 0.61

INFILTRATION - WINDOWS & DOORS: AVG.
Loose

Lin. Ft. x 1.0
Lin. Ft. x 2.0

CEILING: (Area, Sq. Ft.)
Insulated (6”)
Insulated (2”)
Built-up Roof (2” insulated
Built-up Roof (1/2” insulated)
No Insulation

Sq. Ft. x 0.07
Sq. Ft. x 0.10
Sq. Ft. x 0.10
Sq. Ft. x 0.20
Sq. Ft. x 0.33

FLOOR: (Area, Sq. Ft.)
Above Vented Crawl space
Insulated (1:)
Uninsulated
* Slab on Ground
1” Perimeter insulation
* Based on Linear Feet of outside wall

Sq. Ft. x 0.20
Sq. Ft. x 0.50
Lin. Ft. x 1.70
Lin. Ft. x 1.00
TOTAL HEAT LOSS PER °F BTU/HR/°F

Multiply total BTU/HR/°F X 30 and plot on the graph below at 40°F. Draw a straight line from
the 70 base point thru the point plotted at 40°F. The intersection of this heat loss line with the
unit capacity line represents the winter design heating load.

Friedrich Air Conditioning Company
P.O. Box 1540
San Antonio, TX 78295
210.357.4400
www.friedrich.com

ROOM AIR CONDITIONERS
LIMITED WARRANTY
FIRST YEAR
ANY PART: If any part supplied by FRIEDRICH fails because of a defect in workmanship or material within twelve months from date of original
purchase, FRIEDRICH will repair the product at no charge, provided room air conditioner is reasonably accessible for service. Any additional
labor cost for removing inaccessible units and/or charges for mileage related to travel by a Service Agency that exceeds 25 miles one way will
be the responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy within twelve months from the date of the original
purchase.

SECOND THROUGH FIFTH YEAR
SEALED REFRIGERANT SYSTEM: If the Sealed Refrigeration System (defined for this purpose as the compressor, condenser coil, evaporator
coil, reversing valve, check valve, capillary, filter drier, and all interconnecting tubing) supplied by FRIEDRICH in your Room Air Conditioner fails
because of a defect in workmanship or material within sixty months from date of purchase, FRIEDRICH will pay a labor allowance and parts
necessary to repair the Sealed Refrigeration System; PROVIDED FRIEDRICH will not pay the cost of diagnosis of the problem, removal, freight
charges, and transportation of the air conditioner to and from the Service Agency, and the reinstallation charges associated with repair of the
Sealed Refrigeration System. All such cost will be the sole responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy
within sixty months from the date of the original purchase.
APPLICABILITY AND LIMITATIONS: This warranty is applicable only to units retained within the Fifty States of the U.S.A., District of Columbia,
and Canada. This warranty is not applicable to:
1.
2.
3.

Air filters or fuses.
Products on which the model and serial numbers have been removed.
Products which have defects or damage which results from improper installation, wiring, electrical current characteristics, or
maintenance; or caused by accident, misuse or abuse, fire, flood, alterations and/or misapplication of the product and/or units
installed in a corrosive atmosphere, default or delay in performance caused by war, government restrictions or restraints, strikes,
material shortages beyond the control of FRIEDRICH, or acts of God.

OBTAINING WARRANTY PERFORMANCE: Service will be provided by the FRIEDRICH Authorized Dealer or Service Organization in your
area. They are listed in the Yellow Pages. If assistance is required in obtaining warranty performance, write to: Room Air Conditioner Service
Manager, Friedrich Air Conditioning Co., P.O. Box 1540, San Antonio, TX 78295-1540.
LIMITATIONS: THIS WARRANTY IS GIVEN IN LIEU OF ALL OTHER WARRANTIES. Anything in the warranty notwithstanding, ANY
IMPLIED WARRANTIES OF FITNESS FOR PARTICULAR PURPOSE AND/OR MERCHANTABILITY SHALL BE LIMITED TO THE DURATION
OF THIS EXPRESS WARRANTY. MANUFACTURER EXPRESSLY DISCLAIMS AND EXCLUDES ANY LIABILITY FOR CONSEQUENTIAL
OR INCIDENTAL DAMAGE FOR BREACH OF ANY EXPRESSED OR IMPLIED WARRANTY.
Performance of Friedrich’s Warranty obligation is limited to one of the following methods:
1. Repair of the unit
2. A refund to the customer for the prorated value of the unit based upon the remaining warranty period of the unit.
3. Providing a replacement unit of equal value
The method of fulfillment of the warranty obligation is at the sole discretion of Friedrich Air Conditioning.
NOTE: Some states do not allow limitations on how long an implied warranty lasts, or do not allow the limitation or exclusion of consequential or
incidental damages, so the foregoing exclusions and limitations may not apply to you.
OTHER: This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
PROOF OF PURCHASE: Owner must provide proof of purchase in order to receive any warranty related services.
All service calls for explaining the operation of this product will be the sole responsibility of the consumer.
All warranty service must be provided by an Authorized FRIEDRICH Service Agency, unless authorized by FRIEDRICH prior to repairs being
made.
(10-08)

TECHNICAL SUPPORT
CONTACT INFORMATION

FRIEDRICH AIR CONDITIONING CO.
Post Office Box 1540 · San Antonio, Texas 78295-1540
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212
(210) 357-4400 · 877-599-5665 x 846 · FAX (210) 357-4490
Email: tac@friedrich.com
www.friedrich.com
Printed in the U.S.A.

FRIEDRICH AIR CONDITIONING CO.
Post Office Box 1540 · San Antonio, Texas 78295-1540
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212
(210) 357-4400 · FAX (210) 357-4490
www.friedrich.com
Printed in the U.S.A.

Kuhl-ServMan (5-10)

Source Exif Data:

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File Type Extension             : pdf
MIME Type                       : application/pdf
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Linearized                      : Yes
Page Count                      : 87
XMP Toolkit                     : XMP toolkit 2.9.1-13, framework 1.6
About                           : uuid:cf1882c4-1953-4142-927f-31750a2bdfed
Producer                        : Acrobat Distiller 8.0.0 (Windows)
Creator Tool                    : PScript5.dll Version 5.2.2
Modify Date                     : 2010:07:06 13:00:59-05:00
Create Date                     : 2010:06:12 08:38:51-05:00
Metadata Date                   : 2010:07:06 13:00:59-05:00
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Instance ID                     : uuid:9bb9054c-9308-490a-82f0-53ecdf1ab5af
Format                          : application/pdf
Title                           : RAC Standard Chassis IO_(06-12-10)_CS3.indd
Creator                         : Art
Author                          : Art

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Friedrich Kuhl R 410A Users Manual RAC Standard Chassis IO_(06 12 10)_CS3

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