Bryant 3 383Kav Users Manual

383KAV to the manual d7f4dfc0-f126-4f48-a13a-e1d65e6a7625

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SAFETY CONSIDERATIONS

NOTE: Read the entire instruction manual before performing any

service or maintenance.

This symbol →indicates a change since the last issue.

These procedures are for size 45,000 through 155,000 Btuh input

units.

Index Page

SAFETY CONSIDERATIONS..................................................1-2

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS

PROCEDURE...........................................................................2

CARE AND MAINTENANCE................................................2-11

Air Filter Arrangement..........................................................2-3

Blower Motor and Wheel......................................................3-4

Cleaning Heat Exchanger......................................................4-5

Electrical Controls and Wiring .............................................5-6

Troubleshooting...................................................................6-11

Unit Wiring Diagram................................................................8

Service Label ............................................................................9

Troubleshooting Guide......................................................10-11

SAFETY CONSIDERATIONS

Installing and servicing heating equipment can be hazardous due to

gas and electrical components. Only trained and qualified person-

nel should install, repair, or service heating equipment.

Untrained personnel can perform basic maintenance functions

such as cleaning and replacing air filters. All other operations must

be performed by trained service personnel. When working on

heating equipment, observe precautions in the literature, on tags,

and on labels attached to or shipped with the unit and other safety

precautions that may apply.

Follow all safety codes. In the United States, follow all safety

codes including the National Fuel Gas Code (NFGC) NFPA No.

54-1996/ANSI Z223.1-1996 and the Installation Standards, Warm

Air Heating and Air Conditioning Systems (NFPA 90B)

ANSI/NFPA 90B. In Canada, refer to the current edition of the

National Standard of Canada CAN/CGA-B149.1- and .2-M95

Natural Gas and Propane Installation Codes (NSCNGPIC). Wear

safety glasses and work gloves. Have fire extinguisher available

during start-up and adjustment procedures and service calls.

Recognize safety information. This is the safety-alert symbol .

When you see this symbol on the furnace and in instructions or

manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, and CAU-

TION. These words are used with the safety-alert symbol. DAN-

GER identifies the most serious hazards which will result in severe

personal injury or death. WARNING signifies a hazard which

could result in personal injury or death. CAUTION is used to

identify unsafe practices which would result in minor personal

injury or product and property damage. NOTE is used to highlight

suggestions which will result in enhanced installation, reliability,

or operation. Fig. 3—Model 383KAV

Upflow

A94085

Fig. 2—Model 373LAV

Downflow

A94086

Fig. 1—Model 373LAV Horizontal

A94087

®

ama

CANADIAN GAS ASSOCIATION

APPROVED

R

REGISTERED QUALITY SYSTEM

service and

maintenance procedures

GAS-FIRED

INDUCED-COMBUSTION FURNACES

Cancels: SP04-44 SP04-53

9-98

373LAV

383KAV

Series G

—1—

→

WARNING: The ability to properly perform mainte-

nance on this equipment requires certain expertise, me-

chanical skills, tools, and equipment. If you do not

possess these, do not attempt to perform any maintenance

on this equipment other than those procedures recom-

mended in the User’s Manual. FAILURE TO FOLLOW

THIS WARNING COULD RESULT IN POSSIBLE

DAMAGE TO THIS EQUIPMENT, SERIOUS PER-

SONAL INJURY, OR DEATH.

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS

PROCEDURE

CAUTION: Electrostatic discharge can affect electronic

components. Take precautions during furnace installation

and servicing to protect the furnace electronic control.

Precautions will prevent electrostatic discharges from

personnel and hand tools which are held during the

procedure. These precautions will help to avoid exposing

the control to electrostatic discharge by putting the

furnace, the control, and the person at the same electro-

static potential.

1. Disconnect all power to the furnace. DO NOT TOUCH

THE CONTROL OR ANY WIRE CONNECTED TO THE

CONTROL PRIOR TO DISCHARGING YOUR BODY’S

ELECTROSTATIC CHARGE TO GROUND.

2. Firmly touch a clean, unpainted, metal surface of the

furnace chassis which is close to the control. Tools held in

a person’s hand during grounding will be satisfactorily

discharged.

3. After touching the chassis you may proceed to service the

control or connecting wires as long as you do nothing that

recharges your body with static electricity (for example; DO

NOT move or shuffle your feet, DO NOT touch un-

grounded objects, etc.).

4. If you touch ungrounded objects (recharge your body with

static electricity), firmly touch furnace again before touch-

ing control or wires.

5. Use this procedure for installed and uninstalled (un-

grounded) furnaces.

6. Before removing a new control from its container, dis-

charge your body’s electrostatic charge to ground to protect

the control from damage. If the control is to be installed in

a furnace, follow items 1 through 5 before bringing the

control or yourself into contact with the furnace. Put all

used AND new controls into containers before touching

ungrounded objects.

7. An ESD service kit (available from commercial sources)

may also be used to prevent ESD damage.

CARE AND MAINTENANCE

For continuing high performance and to minimize possible equip-

ment failure, it is essential that periodic maintenance be performed

on this equipment. Consult your local dealer as to the proper

frequency of maintenance and the availability of a maintenance

contract.

WARNING: Never store anything on, near, or in contact

with the furnace, such as:

1. Spray or aerosol cans, rags, brooms, dust mops,

vacuum cleaners, or other cleaning tools.

2. Soap powders, bleaches, waxes or other cleaning

compounds, plastic or plastic containers, gasoline, kero-

sene, cigarette lighter fluid, dry cleaning fluids, or other

volatile fluids.

3. Paint thinners and other painting compounds, paper

bags, or other paper products.

A failure to follow this warning could result in corrosion

of the heat exchanger, fire, personal injury, or death.

WARNING: Turn off the gas and electrical supplies to

the unit before performing any maintenance or service.

Follow the operating instructions on label attached to

furnace. A failure to follow this warning could result in

personal injury.

The minimum maintenance that should be performed on this

equipment is as follows:

1. Check and clean air filter each month or more frequently if

required. Replace if torn.

2. Check blower motor and wheel for cleanliness each heating

and cooling season. Clean and lubricate as necessary.

3. Check electrical connections for tightness and controls for

proper operation each heating season. Service as necessary.

CAUTION: As with any mechanical equipment, per-

sonal injury can result from sharp metal edges, etc.,

therefore, be careful when removing parts.

A. Air Filter Arrangement

The air filter arrangement may vary depending on the application.

Refer to Table 1 or 2 for filter size information.

WARNING: Never operate unit without a filter or with

filter access door removed. A failure to follow this

warning could result in fire, personal injury, or death.

TABLE 1—FILTER SIZE INFORMATION FOR

DOWNFLOW/HORIZONTAL FURNACES (IN.)

FURNACE

CASING WIDTH FILTER QUANTITY

AND SIZE FILTER

TYPE

14-3/16 (2) 14 X 20 X 1 Cleanable

17-1/2 (2) 14 X 20 X 1 Cleanable

21 (2) 16 X 20 X 1 Cleanable

24-1/2 (2) 16 X 20 X 1 Cleanable

TABLE 2—FILTER SIZE INFORMATION FOR UPFLOW

FURNACES (IN.)

FURNACE

CASING WIDTH FILTER QUANTITY AND SIZE FILTER

TYPE

Side Return Bottom Return

14-3/16 (1) 16 X 25 X 1* (1) 14 X 25 X 1 Cleanable

17-1/2 (1) 16 X 25 X 1* (1) 16 X 25 X 1 Cleanable

21 (1) 16 X 25 X 1 (1) 20 X 25 X 1* Cleanable

24-1/2 (2) 16 X 25 X 1* (1) 24 X 25 X 1 Cleanable

* Factory-provided with the furnace. Filters may be field modified as required

by cutting to desired size.

—2—

1. Downflow/Horizontal

Each furnace requires 2 filters which are installed in the

return-air duct. (See Fig. 4 and 5.) To remove filters for

cleaning or replacement, proceed as follows:

a. Disconnect electrical power before removing blower

access door.

b. Remove screw from front of door and remove blower

access door.

c. Reach up behind top plate, tilt filters toward center of

return-air plenum, remove filters, and clean as needed.

Replace if torn.

d. Furnaces are equipped with permanent, washable filters.

Clean filters with tap water. Spray water through filter in

opposite direction of airflow.

e. Rinse and let dry. Oiling or coating of filters is not

recommended or required.

f. Reinstall filters.

g. Replace blower access door.

h. Restore electrical power to furnace.

2. Upflow

Each furnace requires 1 or 2 filters which are installed in the

blower compartment. (See Fig. 6.) To remove filters for

cleaning or replacement, proceed as follows:

a. Disconnect electrical power before removing access

doors.

b. Remove blower and control access doors.

c. Release filter retainer from clip at front of furnace

casing. (See Fig. 6.) For side return, clips may be used on

either or both sides of the furnace.

d. Slide filter(s) out.

e. Furnaces are equipped with permanent, washable filters.

Clean filters with tap water. Spray water through filter in

opposite direction of airflow.

f. Rinse and let dry. Oiling or coating of filter is not

recommended or required.

g. Reinstall filter(s).

h. Replace blower and control access doors.

i. Restore electrical power to furnace.

B. Blower Motor and Wheel

For long life, economy, and high efficiency, clean accumulated dirt

and grease from the blower wheel and motor annually.

The following steps should be performed by a qualified service

technician.

Some motors have prelubricated sealed bearings and require no

lubrication. These motors can be identified by the absence of oil

ports on each end of the motor. For those motors with oil ports,

lubricate motor every 5 years if motor is used on intermittent

operation (thermostat FAN switch in AUTO position), or every 2

years if motor is in continuous operation (thermostat FAN switch

in ON position).

NOTE: Remember to disconnect the electrical supply before

removing access doors.

Clean and lubricate as follows:

1. Remove screw from blower access door (downflow/

horizontal furnace only) and remove blower access door.

2. Remove vent pipe enclosure (downflow/horizontal furnace

only) and disconnect short piece of vent pipe from relief

box.

3. Disconnect wires from auxiliary limit on blower housing

(when used on downflow/horizontal furnace only).

4. Remove control.

5. Disconnect electrical leads from control. (See Fig. 6 or 7.)

Note location of wires for reassembly.

6. Remove screws holding blower assembly to blower deck

and slide blower assembly out of furnace.

7. Loosen screw in strap holding motor capacitor to blower

housing and slide capacitor out from under strap.

8. Mark blower wheel, motor, and motor support in relation to

blower housing before disassembly to ensure proper reas-

sembly.

9. Loosen setscrew(s) holding blower wheel on motor shaft.

10. Remove bolts holding motor mount to blower housing and

slide motor and mount out of housing. Disconnect ground

wire attached to blower housing before removing motor.

11. Lubricate motor (when oil ports are provided).

Fig. 4—Horizontal Filter Arrangement

A94307

AIRFLOW

Fig. 5—Downflow Filter Arrangement

A88486

RETURN-AIR

PLENUM

AIRFLOW

ACCESS DOOR

INSTALLATION

POSITION

OF FILTERS

—3—

a. Remove dust caps or plugs from oil ports located at each

end of motor.

b. Use a good grade of SAE 20 nondetergent motor oil and

put 1 teaspoon, 5 cc, 3/16 oz, or 16 to 25 drops in each

oil port. Do not over-oil.

c. Allow time for total quantity of oil to be absorbed by

each bearing.

d. Wipe excess oil from motor housing.

e. Replace dust caps or plugs on oil ports.

12. Remove blower wheel from housing.

a. Mark cutoff location to ensure proper reassembly.

b. Remove screws holding cutoff plate and remove cutoff

plate from housing.

c. Lift blower wheel from housing through opening.

13. Clean blower wheel and motor using a vacuum cleaner with

soft brush attachment. Do not remove or disturb balance

weights (clips) on blower wheel blades. The blower wheel

should not be dropped or bent as balance will be affected.

14. Reinstall blower wheel by reversing items 12 a through c.

Be sure wheel is positioned for proper rotation.

15. Reassemble motor and blower by reversing items 5 through

10. If motor has ground wire, be sure it is connected as

before.

CAUTION: Be sure the motor is properly positioned in

the blower housing. The motor oil ports must be at a

minimum of 45° above the horizontal centerline of the

motor after the blower assembly has been reinstalled in

the furnace.

16. Reinstall blower assembly in furnace.

17. Reinstall control. Connect blower electrical leads to control.

Please note that the common wire connection is 3/16 in. and

all other wire connections are 1/4 in. for assembly. DO

NOT FORCE.

18. Reconnect wires to auxiliary limit switch on blower housing

(downflow/horizontal furnace only).

19. Reinstall vent pipe and enclosure (downflow/horizontal

furnace only).

20. Turn on electrical power and check for proper rotation and

speed changes between heating and cooling.

21. Replace blower access door. Secure with screw (when used

on downflow/horizontal furnace only).

C. Cleaning Heat Exchanger

The following steps should be performed by a qualified service

technician.

NOTE: Deposits of soot and carbon indicate the existence of a

problem which needs to be corrected. Take action to correct the

problem.

If it becomes necessary to clean the heat exchanger because of

carbon deposits, soot, etc., proceed as follows:

1. Turn off gas and electrical power to furnace.

2. Remove screw from front of blower access door

(downflow/horizontal furnace only) and remove control and

blower access doors.

3. Remove vent pipe enclosure (downflow/horizontal furnace

only) and disconnect vent pipe from relief box.

4. Remove 2 screws that secure relief box. (See Fig. 6 or 7.)

5. Disconnect wires to the following components.

a. Blocked vent safeguard

b. Inducer motor

c. Pressure switch

d. Limit overtemperature switch(es)

e. Gas valve

f. Hot surface ignitor

g. Flame-sensing electrode

6. Remove 8 screws that secure flue collector box to center

panel. Be careful not to damage sealant.

7. Remove complete inducer assembly from furnace, exposing

flue openings.

8. Clean cells using field-provided small wire brush, steel

spring cable, reversible electric drill, and vacuum cleaner.

a. Assemble wire brush and steel spring cable.

(1.) Use 48 in. of 1/4-in. diameter high-grade steel

spring cable (commonly known as drain clean-out

or Roto-Rooter cable).

→Fig. 6—Model 383KAV Upflow

A98528

C

OM

24V

HUM

GRYW

BLOCKED

VENT

SAFEGUARD

FLUE

COLLECTOR

BOX

MOUNTING

SCREWS

RELIEF

BOX

CONTROL

FILTER

RETAINER

WASHABLE

FILTER

→Fig. 7—Model 373LAV Downflow

A98529

VENT PIPE

ENCLOSURE

BLOCKED

VENT

SAFEGUARD

MANUAL

RESET LIMIT

SWITCHES

AUXILIARY

LIMIT

SWITCH

(WHEN USED)

MOUNTING

SCREWS

RELIEF

BOX

C

OM

24V

HUM

GRYW

CONTROL

BOARD

—4—

→

(2.) Use 1/4-in. diameter wire brush (commonly known

as 25-caliber rifle cleaning brush).

NOTE: The materials needed in items (1.) and (2.) can usually be

purchased at local hardware stores.

(3.) Insert twisted wire end of brush into end of steel

spring cable, and crimp tight with crimping tool or

strike with ball-peen hammer. TIGHTNESS is very

important.

(4.) Remove metal screw fitting from wire brush to

allow insertion into cable.

b. Clean each heat exchanger cell.

(1.) Attach variable-speed, reversible drill to end of

steel spring cable (end opposite brush).

(2.) Insert brush end of cable into upper opening of cell

and slowly rotate with drill. DO NOT force cable.

Gradually insert at least 36 in. of cable into 2 upper

passes of cell. (See Fig. 8.)

(3.) Work cable in and out of cell 3 or 4 times to obtain

sufficient cleaning. DO NOT pull cable with great

force. Reverse drill and gradually work cable out.

(4.) Remove burner assembly and cell inlet plates.

CAUTION: Be very careful when removing the burner

assembly to avoid breaking the ignitor. See Fig. 9 for the

correct ignitor location.

(5.) Replace screws in center panel and cells before

cleaning.

(6.) Insert brush end of cable in lower opening of cell,

and proceed to clean 2 lower passes of cell in same

manner as 2 upper passes.

(7.) Repeat foregoing procedures until each cell in

furnace has been cleaned.

(8.) Remove residue from each cell using vacuum

cleaner.

(9.) Clean burner assembly using vacuum cleaner with

soft brush attachment.

(10.) Clean flame sensor with fine sandpaper.

(11.) Reinstall cell inlet plates and burner assembly.

Care must be exercised to center the burners in the

cell openings.

9. After cleaning flue openings, check sealant on flue collector

to ensure that it has not been damaged. If new sealant is

needed, contact your dealer or distributor.

10. Clean and replace flue collector assembly, making sure all

8 screws are secure.

11. Reinstall relief box.

12. Reconnect wires to the following components.

a. Blocked vent safeguard

b. Inducer motor

c. Pressure switch

d. Limit overtemperature switch(es)

e. Gas valve

f. Hot surface ignitor

g. Flame-sensing electrode

13. Reconnect vent pipe to relief box. Replace vent pipe

enclosure (downflow/horizontal furnace only).

14. Replace blower access door only.

15. Turn on electrical power and gas.

16. Set thermostat and check furnace for proper operation.

WARNING: Never use a match or other open flame to

check for gas leaks. Use a soap-and-water solution. A

failure to follow this warning could result in fire, personal

injury, or death.

17. Check for gas leaks.

18. Replace control access door on upflow furnace.

19. On downflow/horizontal furnaces, remove blower access

door, replace control access door first, then replace blower

access door and secure with screw in front of door.

D. Electrical Controls and Wiring

CAUTION: There may be more than 1 electrical supply

to the unit. Check accessories and cooling unit for

additional electrical supplies.

Fig. 8—Cleaning Heat Exchanger Cell

A91252

Fig. 9—Position of Ignitor to Burner

A93347

BURNER

IGNITOR

11 32"

78"

C

L

C

L

IGNITOR

ASSEMBLY

CELL

PANEL

BURNER

13 32"

HOT

SURFACE

IGNITOR

ASSEMBLY

—5—

→

→

The electrical ground and polarity for 115-v wiring must be

maintained properly. Refer to Fig. 10 for field wiring information

and to Fig. 12 for unit wiring information.

NOTE: If the polarity is not correct, the STATUS LED on the

control center will flash rapidly and prevent the furnace from

operating. The control system also requires an earth ground for

proper operation of the control board and flame sensing.

The 24-v circuit contains an automotive-type, 3-amp fuse located

on the control board. (See Fig. 11.) Any direct shorts of the 24-v

wiring during installation, service, or maintenance will cause this

fuse to blow. If fuse replacement is required, use ONLY a fuse of

identical size.

With power to the unit disconnected, check all electrical connec-

tions for tightness. Tighten all screws on electrical connections. If

any smoky or burned connections are found, disassemble the

connection, clean all parts, strip wire, and reassemble properly and

securely.

Reconnect electrical power to the unit and observe unit through 1

complete operating cycle. Electrical controls are difficult to check

without proper instrumentation; if there are any discrepancies in

the operating cycle, contact your dealer and request service.

For an explanation of fault codes, refer to service label located on

blower access door or Fig. 13, and the troubleshooting guide.

The control center stores 1 fault code (the last fault to occur) for a

period of 48 hrs or until the 115- or 24-v power is interrupted.

NOTE: Removing blower access door will open blower access

door switch and terminate 115-v power to control center, and fault

code will be erased. Look into blower access door sight glass for

current LED status.

1. To retrieve fault code, proceed with the following:

NOTE: NO thermostat signal may be present at control center,

and all blower time delay off periods must be completed.

a. Leave 115-v power to furnace turned on.

b. Look into blower access door sight glass for current

LED status.

NOTE: Leave blower access panel installed to maintain power to

control center to view current LED status.

c. Remove control access door.

d. BRIEFLY remove either wire from the main limit switch

until LED goes out, then reconnect it.

NOTE: If wire to main limit is disconnected longer than 4 sec,

main blower starts, and retrieval request is ignored.

2. When above items have been completed, the following will

occur:

a. LED flashes a fault code 4 times. Record this fault code

for further troubleshooting.

b. Inducer motor starts and continues to run the entire

component test.

c. Hot surface ignitor is energized for 15 sec, then de-

energized.

d. Main blower operates at cooling speed for 10 sec, then

turns off.

e. Main blower operates at heating speed for 10 sec, then

turns off.

f. Inducer motor stops.

Items a through e above will assist in furnace troubleshoot-

ing since all components are functionally operated except

the gas valve. This procedure is also referred to as "Com-

ponent Test."

3. Operate furnace through 1 heat cycle to test for proper

operation and check LED status.

4. If furnace is operating properly and LED indicates proper

operation, replace control access door.

5. Component Test can also be initiated by performing the

following:

a. Remove control access door.

b. Remove blower access door.

c. Manually close blower access door switch.

WARNING: Blower access door switch opens 115-v

power to control center. No component operation can

occur. Caution must be taken when manually closing this

switch for service purposes. Failure to follow this warn-

ing could result in personal injury or death.

d. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect

terminal on control center (adjacent to LED diagnostic

light), and Com terminal on thermostat connection

block. (See Fig. 11.)

NOTE: If TEST to Com terminals are jumpered longer than 2 sec,

LED will flash rapidly, and retrieval request will be ignored.

e. Component Test will function as described in item 2

above.

f. Check LED status.

g. If LED status indicates proper operation, release blower

access door switch, replace blower access door, and

replace control access door.

E. Troubleshooting

Refer to the service label. (See Fig. 13.) Pages 10 and 11 contain

a troubleshooting guide. This guide can be a useful tool in isolating

furnace operation problems. Beginning with the word "Start,"

answer each question and follow the appropriate arrow to the next

item.

The guide will help to identify the problem or failed component.

After replacing any component, verify correct operation sequence.

—6—

→Fig. 10—Heating and Cooling Application Wiring Diagram

A98209

115-V

FIELD-SUPPLIED

DISCONNECT

AUXILIARY

J-BOX

CONTROL

BOX

24-V

TERMINAL

BLOCK

THREE-WIRE

HEATING-

ONLY

FIVE

WIRE

NOTE 1

NOTE 2

FIELD-SUPPLIED

DISCONNECT

CONDENSING

UNIT

TWO

WIRE

FURNACE

R

G

C

WCR GY

GND

GND

FIELD 24-V WIRING

FIELD 115-, 208/230-, 460-V WIRING

FACTORY 24-V WIRING

FACTORY 115-V WIRING

208/230- OR

460-V

THREE

PHASE

208/230-V

SINGLE

PHASE

WHT

BLK

WHT

BLK

NOTES: Connect Y-terminal as shown for proper operation.

Some thermostats require a "C" terminal connection as shown.

If any of the original wire, as supplied, must be replaced, use

same type or equivalent wire.

W

Y

GND

THERMOSTAT

TERMINALS

1.

2.

3.

Fig. 11—Control Board

A95086

C

OM



24V



HUM

GRYW

3-AMP FUSE

HUMIDIFIER TERMINAL

(24-VAC 0.5 AMP MAX)

LED OPERATION &

DIAGNOSTIC LIGHT

HARNESS CONNECTOR

24-V TRANSFORMER SEC-2

SPARE-1

SPARE-2

EAC-1

EAC-ELECTRONIC AIR CLEANER

TERMINALS (115-VAC 1.5 AMP MAX)

EAC-2

115-VAC (L2) NEUTRAL

CONNECTION

24-V THERMOSTAT

TERMINALS

BLOWER SPEED

SELECTION TERMINALS

INDUCER MOTOR

CONNECTOR

115-VAC (L1)

POWER SUPPLY

HOT SURFACE

IGNITOR CONNECTOR

HEAT

COOL

SEC-1

TEST/TWIN

—7—

→Fig. 12—Wiring Diagram

A98200e

PCB

BLOWER OFF DELAY

SELECTION CHART

90 SEC

135 SEC

180 SEC

225 SEC

GVR

HI/LO

RELAY

SEC-1 SEC-2

PL1 321

654

987

LED

TEST/TWIN

BLOWER

OFF

DELAY

G

R

Y

W

C

HUM

HSIR IDR BLWR

BLOWER

SPEED

SELECT

FU1

COOL

HEAT

L2

PL3

PL2

VAC

120

L1 PR1 1

2

1

2

3

PR2

24 VAC-3A

FUSE

SPARE-2

SPARE-1

EAC-1

EAC-2

C

1.5 AMP

12

PL5 WHT

BLK

WHT

WHT

BLK

BLK

HSI

BLK

WHT

WHT (COM)

RED (LO)

BLU (MED LO)

NOTE #7

OL

START

BLWM

YEL (MED HI)

BLK (HI)

BRN

BRN

TRAN

BLU

RED

BLK

WHT

WHT (COM)

GRN

CAP

RED

NOTE #5

RED

ORN

FUSED DISCONNECT

SWITCH (WHEN REQ'D)

NOTE #4

FU2

BLK

WHT

GRN

GRN

JB

LEGEND

ALS AUXILIARY LIMIT SWITCH, OVERTEMP. -MANUAL RESET, SPST-(N.C.)

BLWR BLOWER MOTOR RELAY, SPST-(N.O.)

BLWM BLOWER MOTOR

BVSS BLOCKED VENT SHUTOFF SWITCH, SPST - (N.C.)

CAP CAPACITOR

CPU MICROPROCESSOR AND CIRCUITRY

DSS DRAFT SAFEGUARD SWITCH

EAC-1 ELECTRONIC AIR CLEANER CONNECTION (115 VAC 1.5 AMP MAX.)

EAC-2 ELECTRONIC AIR CLEANER CONNECTION (COMMON)

FL FUSIBLE LINK

FRS FLAME ROLLOUT SW. -MANUAL RESET, SPST-(N.C.)

FSE FLAME PROVING ELECTRODE

FU1 FUSE, 3 AMP, AUTOMOTIVE BLADE TYPE, FACTORY INSTALLED

FU2 FUSE OR CIRCUIT BREAKER CURRENT INTERRUPT DEVICE

(FIELD INSTALLED & SUPPLIED)

GV GAS VALVE-REDUNDANT OPERATORS

GVR GAS VALVE RELAY, DPST-(N.O.)

HI/LO BLOWER MOTOR SPEED CHANGE RELAY, SPDT

HSI HOT SURFACE IGNITOR (115 VAC)

HSIR HOT SURFACE IGNITOR RELAY, SPST-(N.O.)

HUM 24VAC HUMIDIFIER CONNECTION (.5 AMP. MAX.)

IDM INDUCED DRAFT MOTOR

IDR INDUCED DRAFT RELAY, SPST-(N.O.)

ILK BLOWER ACCESS PANEL INTERLOCK SWITCH, SPST-(N.O.)

JB JUNCTION BOX

LED LIGHT-EMITTING DIODE FOR STATUS CODES

LGPS LOW GAS PRESSURE SWITCH, SPST-(N.O.)

LS LIMIT SWITCH, AUTO RESET, SPST(N.C.)

OL AUTO-RESET INTERNAL MOTOR OVERLOAD TEMP. SW.

PCB PRINTED CIRCUIT BOARD

PL1 9-CIRCUIT CONNECTOR

PL2 2-CIRCUIT PCB CONNECTOR

PL3 3-CIRCUIT IDM CONNECTOR

PL5 2-CIRCUIT HSI/PCB CONNECTOR

PRS PRESSURE SWITCH, SPST-(N.O.)

TEST/TWIN COMPONENT TEST & TWIN TERMINAL

TRAN TRANSFORMER-115VAC/24VAC

JUNCTION

UNMARKED TERMINAL

PCB TERMINAL

FACTORY WIRING (115VAC)

FACTORY WIRING (24VAC)

FIELD WIRING (115VAC)

FIELD WIRING (24VAC)

CONDUCTOR ON PCB

FIELD WIRING TERMINAL

FIELD GROUND

EQUIPMENT GROUND

FIELD SPLICE

PLUG RECEPTACLE

L1 NEUTRAL

L1 BLWR

HI/LO

TO 115VAC FIELD DISCONNECT

NOTE #4

EQUIPMENT GROUND

SPARE-2

HEAT

SPARE-1

COOL NOTE #7

COM

HSIR

EAC-1

START

OL

COM

HI

MED HI

MED LO

LO

BLWM

SCHEMATIC DIAGRAM

(NATURAL GAS & PROPANE)

EAC-2

11HSI

2

PL52

PL2

3PL3

PR2

115VAC

PR1

TRAN

24VAC

1

2

IDR

TEST/TWIN

FU1 NOTE #6

CAP

L2

PL1

8

FSE

9

6

5

CPU

HSIR

IDR

BLWR

Y

G

C

R

W

GVR-2

SEC-1

HI/LO

GVR

SEC-2

NOTES:

322869-101 REV. E

1. If any of the original equipment wire is replaced use wire rated for 105˚C.

2. Inducer (IDM) and blower (BLWM) motors contain internal auto-reset thermal overload switches (OL).

3. Blower motor speed selections are for average conditions, see installation instructions for details on

optimum speed selection.

4. Use only copper wire between the disconnect switch and the furnace junction box (JB).

5. This wire must be connected to furnace sheetmetal for control to detect flame.

6. Replace only with a 3 amp fuse.

7. Yellow lead not on all motors.

8. Blower-on delay, gas heating 45 seconds, cooling or heat pump 2 seconds.

9. Blower-off delay, gas heating 90, 135, 180 or 225 seconds, cooling or heat pump 90 seconds.

(135 seconds only on some models)

10. Ignition-lockout will occur after four consecutive unsuccessful trials-for-ignition. Control will auto-reset

after three hours.

11. When used, auxiliary limit switch (ALS) is on some downflow models only. When used, FL is on upflow

models only.

12. Some models may have spade quick connect terminals.

13. Factory connected when LGPS is not used.

14. Factory connected when BVSS is not used. BVSS used when Chimney Adapter Accessory Kit is

installed.

BLK

OM

SW2

SW1

OM

3

4

7

1

OM

HUM

IDM

ILK

DSS BVSS

PRS

ILK

L1

NEUTRAL

IDM

(WHEN USED)

NOTE #14

NOT USED

NOT USED

NOT USED

GRN 2-C

FSE

1-M 3-P

GV

BLU

PRS

DSS

BVSS

(WHEN USED)

NOTE #14

WHT

LS

FL

(NOT ON ALL MODELS)

NOTE #9

FRS1 FRS2

LS FL

NOTE #12

ORN ORN ORN

ALS

(WHEN USED)

ORN

NOTE #11

LGPS

(WHEN USED)

NOTE #13

NOTE #14

NOTE #11

2

GVR-1

NOTE #5

1-M 2-C

GV

3-P

NOTE #14

ALS

(WHEN USED)

(WHEN USED)

NOTE #13 LGPS

(WHEN USED)

NOTE #13

NOTE #11

YEL

FRS1 FRS2

(WHEN USED) NOTE #11

—8—

Fig. 13—Service Label

A96263

SERVICE

11 NO PREVIOUS CODE - Stored status codes are erased when power (115V or 24V)

to control is interrupted or 48 hours after each fault is cleared.

12 BLOWER ON AFTER POWER UP (115V or 24V) - Blower runs for 90 seconds,

if unit is powered up during a call for heat (R-W closed).

13 LIMIT OR FLAME ROLL-OUT SWITCH LOCKOUT - Auto reset after three hours.

For flame roll-out switch or fuse link, refer to #33.

14 IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to #34.

21 GAS HEATING LOCKOUT - Control will NOT auto reset.

Check for: - Stuck gas valve relay on control or miswire to gas valve circuit.

22 ABNORMAL FLAME-PROVING SIGNAL - Flame is proved while gas valve is

de-energized. Inducer will run until fault is cleared. Check for:

- Stuck-open gas valve or leaky gas valve.

23 PRESSURE SWITCH DID NOT OPEN Check for:

- Obstructed pressure tubing. - Defective pressure switch

(stuck closed).

24 SECONDARY VOLTAGE FUSE IS OPEN

Check for: - Short circuit in secondary voltage (24V) wiring.

31 PRESSURE, DRAFT SAFEGUARD, AUXILIARY-LIMIT (when used), OR

BLOCKED VENT SHUTOFF (when used) SWITCH DID NOT CLOSE OR

REOPENED - If open longer than five minutes, inducer shuts off for 15 minutes

before retry. Check for:

- Proper vent sizing and condensate pitch - Inadequate Combustion air supply.

or sag. - Low inducer voltage.

- Vent restriction or high winds. - Disconnected or obstructed

- Defective inducer motor or start capacitor. pressure tubing.

- Defective pressure switch or connections. If it opens after trial for ignition period,

blower will come on for 90 second recycle delay.

33 LIMIT OR FLAME ROLL-OUT SWITCH IS OPEN - If open longer than three

minutes,code changes to #13. Check for:

- Defective blower motor or start capacitor. - Dirty filter or restricted duct system.

- Loose blower wheel. - Defective switch or connections.

- Inadequate Combustion air supply Flame Roll-out Switch or fuse link.

- Open Flame Roll-out switch,or fuse link. Manual reset or replace.

34 IGNITION PROVING FAILURE - Control will try three more times before a lockout

#14 occurs. If flame signal lost after trial for ignition period, blower will

come on for 90 second recycle delay. Check for:

- Oxide buildup on flame sensor (clean with fine sandpaper).

- Proper flame sense microamps (.5 microamps D.C. minimum).

- Gas valve turned off. - Manual shut-off valve. - Low inlet gas pressure.

- Green wire MUST be connected to furnace sheet metal.

- Inadequate flame carryover or rough ignition.

COMPONENT TEST

To initiate the component test sequence,shut OFF the room thermostat or disconnect the

"R" thermostat lead. Briefly short the TEST terminal to the ’Com 24V’ terminal. Status

LED will flash code and then turn ON the inducer motor. The inducer motor will run for

the entire component test. The hot surface ignitor, blower motor-heat speed, and blower

motor-cool speed will be turned ON for 10-15 seconds each.

G

R

Y

W

Com

HUM

TEST

STATUS

320615-102 REV. H

CONTINUOUS OFF - Check for 115VAC at L1 and L2, and 24VAC at

SEC-1 and SEC-2.

CONTINUOUS ON - Control has 24V power.

RAPID FLASHING - Line voltage (115V) polarity reversed. If twinned, refer to

twinning kit instructions.

LED CODE

EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE

FIRST DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE

SECOND DIGIT BY THE NUMBER OF LONG FLASHES.

1

2

3

4

5

6

7

8

9

STATUS

24V

—9—

Is circuit breaker closed?

Close door switch and go to start.Is red LED status light on? Is door switch closed?

Is red LED status light blinking

rapidly without a pause?

Is there 115v going to switch?

Replace door switch.Replace control center.

Replace transformer.

Is red LED status light blinking

ON/OFF slowly with a

combination of short and long

flashes?

Check for correct line voltage

polarity. If units are twinned,

check for proper low-voltage 

(24v) transformer phasing.

Check for previous fault by 

momentarily shorting the TEST

terminal and the C terminal until

the LED goes out. LED will flash

the status code of any previous

fault or the code No. 11 (1 short

and 1 long flash) if no previous

fault. After the control repeats the

code 3 times, the control will go

through a brief component test

sequence. The inducer will start

and run for the entire component

test. The HSI, blower motor heat

speed, and blower motor cool 

speed will run for 10-15 sec each.

Determine status code. The

status code is a 2 digit number

with the first digit determined by

the number of short flashes and

the second digit by the number of

long flashes.

Once status code is determined,

the control will go through a brief

component test sequence. The

inducer will start and run for the

entire component test. The HSI,

blower motor heat speed, and 

blower motor cool speed will run

for 10-15 sec each.

Was there a previous fault code

other than No. 11?

Does control respond to W, Y,

or G 24-vac thermostat signals?

Run system through a heating or

cooling cycle to check operation.

Status codes are erased after 48

hrs or whenever power (115v

or 24v) is interrupted.

Go to section with status code

determined.

Is there 115v at L1 and L2?

Close circuit breaker and

go back to start.

Check for continuity in wire from circuit

breaker to furnace.

NO NO NO

NO NO

NO

YES

YES

YES

YES

YES

YES

YES

NO

NO

YES

YES

YES

START

Is there 24v at SEC-1 and SEC-2?

NO Is 24 vac present at W, Y, or G

terminals on the control?

Replace control if it does not

respond to 24-vac signal at W, Y,

or G screw terminals.

Check room thermostat or

interconnecting cable.

YES

NO

NO

TROUBLESHOOTING GUIDE

—10—

11 NO PREVIOUS FAULT - Faults

are erased after 48 hrs or

whenever power (115V or 24V)

is interrupted. Run system

through a heating or cooling

cycle to recheck system.

12 BLOWER ON AFTER POWER

UP (115V OR 24V) - Normal 

operation. Blower will run for 90

sec when furnace power is

interrupted during a call for heat

and R-W closes.

13 LIMIT OR FLAME ROLLOUT

SWITCH LOCKOUT - Limit

switch was open longer than

3 minutes. Auto-reset will occur

after 3 hrs. Flame rollout switch

requires manual reset.

See No. 33

14 IGNITION LOCKOUT - System

failed to ignite gas and prove

flame in 4 attempts. Control will

auto-reset in 3 hrs.

See No. 34

21 GAS HEATING LOCKOUT - 

Turn off power and wait 5

minutes to retry.

Check for:

Unplug ignitor harness from control

center and inititate another 

component test sequence and check

for 115v between pins 1 and 2 on

the board. Was there 115v present

for the 17 sec period?

Replace control board.

Check for continuity in the harness

and ignitor. Replace defective

component.

Reconnect the R thermostat lead

and set thermostat to call for heat.

Connect voltmeter across gas valve

connections. Does gas valve

receive 24v?

Check connections. If OK, replace

control board.

Does gas valve open and allow gas

to flow?

Check that all gas valves are turned

on. Replace valve.

Do main burners ignite?

Do main burners stay on?

Allow blower to come on and repeat

test to check for intermittent

operation.

Repeat call for heat and check flame

sensor current during trial for ignition

period. Is the dc microamperes

below 0.5?

Check connections including equipment 

ground and retry. Green wire must be

connected to furnace sheet metal. If 

current is near typical value and control 

will not stay on, replace control board.

Clean flame sensor with fine

sandpaper and recheck current. 

Current is nominally 4.0 to 6.0

microamps DC.

Is current near typical value?

Replace electrode.

Will main burner ignite and stay on?

Replace control board.

Fixed.

• Stuck closed gas valve relay

on control.

• Miswire or short to gas valve

wire.

22 ABNORMAL FLAME PROVING

SIGNAL - Flame was sensed

while gas valve was

de-energized. Inducer will run

until fault is cleared.

Check for:

• Stuck open gas valve solenoid

or leak.

• Defective control board.

23 PRESSURE SWITCH WILL

NOT OPEN - Check for:

• Disconnected or obstructed

pressure tubing.

• Defective pressure switch.

24 LOW-VOLTAGE FUSE IS

OPEN - Check for:

• Short in low-voltage wiring

including thermostat leads

shorting to ductwork or

furnace cabinet. Disconnect

thermostat leads to isolate

short circuit.

31 PRESSURE, DRAFT 

SAFEGUARD (WHEN USED),

OR AUXILIARY LIMIT (WHEN

USED) SWITCH WILL NOT 

CLOSE OR REOPEN - If open

longer than 5 minutes, inducer 

shuts off for 15 minutes before

retry.

Check for:

• Proper vent sizing or pitch or

sag.

• Vent restrictions or high winds.

• Defective inducer motor.

• Low-line voltage (115v).

• Motor start capacitor.

• Low inlet gas pressure.

• Defective pressure switch or

connections. If it opens after

trial for igniton period, blower

will come on for 90 sec

recycle delay.

Inadequate combustion air

(for draft safeguard and

auxiliary limit switches only).



33 LIMIT OR FLAME ROLLOUT

SWITCH IS OPEN - If limit 

switch is open longer than 3

minutes, code changes to No. 13.

Check for:

• Blower motor failure.

• Motor start capacitor.

• Open flame rollout switch,

manual reset.

•

Dirty or restrictive filter.

Defective limit switch or 

connections.

Loose blower wheel.

34 IGNITION PROVING FAILURE -

If flame is not sensed during the

trial for ignition period, the control

will repeat the ignition sequence

3 more times before going into

lockout, No. 14.

If flame signal is lost after trial for

ignition period, blower will come

on for 90 sec recycle delay.

Check for the following items first

before proceding to the next step.

• Gas valve turned off.

• Manual shut-off valve.

• Green wire must be connected

to furnace sheet metal.

To determine whether the

problem is in the gas valve,

igniter, or flame sensor, the

system can be operated in the

component test mode to check

out the ignitor. First, remove the

R thermostat connection from the

control board and initiate the

component test sequence. Does

the ignitor glow orange/white hot

by the end of the 17 sec warm-up

period?

Check for:

• Inadequate flame carryover on

rough ignition.

• Low inlet gas pressure.

NO

YES

YES

YES

YES

YES

YES

YES

YES

YES

NO

NO

NO

NO

NO

NO

NO

NO

•

•

Inadequate combustion air

supply (flame rollout

switch only).

•Restricted duct system.•

•

A98523

—11—

A94328

SERVICE TRAINING

Packaged Service Training programs are an excellent way to increase your

knowledge of the equipment discussed in this manual, including:

 • Unit Familiarization • Maintenance

 • Installation Overview • Operating Sequence

A large selection of product, theory, and skills programs is available, using popular

video-based formats and materials. All include video and/or slides, plus companion

book.

Classroom Service Training plus "hands-on" the products in our labs can mean

increased confidence that really pays dividends in faster troubleshooting, fewer

callbacks. Course descriptions and schedules are in our catalog.

CALL FOR FREE CATALOG 1-800-962-9212

[ ] Packaged Service Training [ ] Classroom Service Training

© 1998 Bryant Heating & Cooling Systems 7310 W. Morris St. Indianapolis, IN 46231 —12— Printed in U.S.A. sp0453 Catalog No. 5337-301