HYDRO FLAME 1H2C Hflamefurn04

User Manual: HYDRO FLAME 1H2C

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1
September 2003
INTRODUCTION
The 2004 edition of the Atwood Furnace Service Manual is a resource created to help
service technicians identify Atwood product by serial number, diagnose service
problems and efficiently and effectively process warranty claims.
Changes to the Hydro Flame furnaces include:
• Ignition boards in the 79, 85 and 89 series furnaces now have the blower relay
incorporated into the PC board. These boards are compatible with previous Hydro
Flame furnaces. There is no longer a remote relay.
• New boards have a diagnostic ability with 4 fault codes.
• Furnaces with no outside access doors (only an exhaust vent) became available in
2003; the initials L/D in the model number identify these models. The gas valve was
re-oriented with a longer inlet manifold to make this possible.
Each of the manuals within this series offers a general overview of the product as well
as more specific product information. For each product within the manual, you will find
model identification, recommended tools and equipment, a sequence of operation,
warnings, annual maintenance procedures, parts and troubleshooting guides, warranty
procedures, flat rate schedules, and replacement part reference charts.
Due to the rapidly changing personal computer revolution we have placed
troubleshooting information in a variety of places to make sure that the most accurate
information is available. The best place to find the current information about Atwood
products is our website: www.atwoodmobile.com. At our website brochures may be
downloaded, trouble shooting guides reviewed and the latest information bulletins can
be read. In addition all Atwood Authorized Service Centers are listed on our site,
accessible via an easy-to-use search system.
Service for all Atwood products is handled out of our Rockford location. Should you
have any questions regarding our products or the information contained in this manual
simply dial 1-800-825-4328. Be sure to have the Model and Serial Number when you call.
Atwood Service Department
Disclaimer: The data presented in this publication is obtained from the most reliable sources, and is believed to be accurate as of the date of publication.
Responsibility for typographical errors or omission of data cannot be assumed by the publishers.
2
Recommended Tools and Equipment
U-Tube Manometer - P/N 34706 - This is the most accurate device for measuring gas pressure. If you use a
dial-type manometer, it should be calibrated periodically with this type of manometer.
Slack Tube Manometer - P/N 34880 - A more portable U-Tube Manometer.
Multi-meter - This is the most effective meter capable of reading voltage, amperage and continuity. A test light
cannot give you specific enough information to trouble-shoot a furnace properly.
Circuit Board Tester - P/N 32779 - This is a table top device that will test all furnace circuit boards. It will
specifically test the following board functions: power, spark, lamp, sense and valve. It will test Fenwal and
Channel circuit boards.
Air Speed Indicator - P/N 34207 - This hand held device will let you determine air flow out of a heat register. It
will help you isolate restricted ducting.
Incline Manometer - P/N 34208 - This meter measures the static pressure of the furnace cavity. It provides an
x-ray of the total heating system. It will indicate if all of the heat being produced by the furnace is being
sufficiently distributed out to the heat registers.
Long-handled Allen Wrenches (9/64˝ and 1/8˝) - These two wrenches are necessary to remove the blower
wheel and the combustion wheel.
Common Hand Tools - 1/4˝ nut drivers, open end wrenches, flat blade and Phillips screw drivers.
Leak Test Solution - A solution that bubbles when applied to gas fittings or connections showing where a gas
leak is present.
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
Manometer
connection
Fill here
U-TUBE MANOMETER
with 1/8” pipe nipple VOLT OHM-AMP METER
CIRCUIT BOARD TESTER
3
hydro flame™ FURNACES TABLE OF CONTENTS
Recommended Tools & Equipment ............................................................................................................................................................................................................2
79/80 Series
Model Identification..................................................................................................................................................................................................................................................4
79-II Directional Air Box Insert......................................................................................................................................................................................................................5
85 Series
Model Identification..................................................................................................................................................................................................................................................6
89 Series & 2-Stage Model
Model Identification..................................................................................................................................................................................................................................................7
Wiring Diagrams
7900-II/8000-II Series ............................................................................................................................................................................................................................................8
8500 Series ..........................................................................................................................................................................................................................................................10-11
8900-III Series & 79 / 85 / 89 with blower control ignition board..........................................................................................................................12
2-Stage Furnace & Diagnostic Chart..................................................................................................................................................................................................13
Model 1H2C Digital Thermostat..................................................................................................................................................................................................................14
Model 2H2C Digital Thermostat..................................................................................................................................................................................................................15
Sequence of Operation
DC Models (standard 1-Stage)..................................................................................................................................................................................................................16
DC Models (2-Stage Excalibur™)..............................................................................................................................................................................................................17
Pilot Models..................................................................................................................................................................................................................................................................18
AC Models......................................................................................................................................................................................................................................................................19
Safety & Warnings........................................................................................................................................................................................................................................................20
Annual Preventative Maintenance Inspection............................................................................................................................................................................21
Furnace Parts
Mechanical Thermostat ....................................................................................................................................................................................................................................22
Circuit Breaker & Motor....................................................................................................................................................................................................................................23
Circuit Boards..............................................................................................................................................................................................................................................................23
Relay ....................................................................................................................................................................................................................................................................................24
Sail Switch......................................................................................................................................................................................................................................................................24
Limit Switch ..................................................................................................................................................................................................................................................................24
Dual Solenoid Gas Valve..................................................................................................................................................................................................................................25
Burner Head, Electrode & Valve Assembly ..................................................................................................................................................................................25
The 4 Always (Gas Pressure, Voltage, Ducting, Return Air)................................................................................................................................26-27
Trouble Shooting Guides
Thermostat ....................................................................................................................................................................................................................................................................29
Electronic Ignition Models ....................................................................................................................................................................................................................30-31
Pilot Model............................................................................................................................................................................................................................................................32-33
Furnace Terminology ......................................................................................................................................................................................................................................34-35
Return Goods Policy (RETURN ADDRESS)..................................................................................................................................................................................................36
Warranty Procedures................................................................................................................................................................................................................................................36
Warranty ..................................................................................................................................................................................................................................................................................37
Flat Rate Schedule......................................................................................................................................................................................................................................................38
Furnace Parts Breakdowns
7900-II/8000-II Series..........................................................................................................................................................................................................................................39
8500-III Series ............................................................................................................................................................................................................................................................40
8500-IV Series............................................................................................................................................................................................................................................................41
8900-III Series ............................................................................................................................................................................................................................................................42
2-Stage Model 1522 & 2334........................................................................................................................................................................................................................43
2-Stage Model 2540 ............................................................................................................................................................................................................................................44
Replacement Part Reference
85-IV 16, 85-IV 20, 85-IV 25, 85-IV 31, 85-IV 35, 1522, 2334 2-STAGE & R-25 ........................................................................................45
7912-II, 7900-II 16 & 20, 8012-II, 85-III 16-20, 85-III 25, 85-III 31-35, 89-III DC, 89-III AC, 2540 2-STAGE ..................48
85-II 16-20, 85-II 25, 82-II 31-35, 89-I DC, 89-I AC, 89-II DC, 89-II AC, FA 79D, FA 79P, HF 80D, HF 80P ..................53
85-I 16-20, 85-I 25, 85-I 31-35, DC82 25-32, DC82 35-41, AC 82, FA 76D, FA 78 25-32, FA 72D, FA 72P..................56
Atwood Furnace Installation Parts
Atwood Training Tapes and Manuals ORDER BLANK
4
79 / 80 Series Model Identification
Applications - This unit is typically installed in tent campers, truck campers and small travel trailers due to its
small size and lower BTU capacities. It is sometimes used in larger trailers or motor homes for smaller zone
heating.
Heat Outlets - This furnace is usually set up as a front discharge unit. However, it does have a 4" duct outlet on
either side of its casing for soft ducting to remote outlets. To determine the most efficient ducting configuration,
refer to Minimum Ducting Configuration.
Directional Air Box Insert - If you need to direct heat to the front or rear of a camper and you cannot use soft
ducting and registers, an optional diverter plate with 55 degree louvers can be added to the front exhaust box.
Serviceability - Practically all of the components of this furnace are accessible by removing the front grille.
Therefore, the furnace does not need to be removed for most repairs. The only components that are not accessible
without removing the furnace are the blower motor, sail switch and blower and combustion wheels.
Power Consumption - The 79 series furnace draws only 3.4 amps. However, there is an 8012 series furnace that
has a heating capacity of 12,000 BTU’s and only draws 1.8 amps. This furnace is ideal for dry camping.
MINIMUM DUCTING CONFIGURATION
7912-II 7916-II 7920-II - SIDE DISCHARGE UNITS -
Provides the most air flow and heat to remote heat
outlets. The duct runs need to be as short and straight as
possible for optimal heating.
7912-II 7916-II 7920-II - SIDE DISCHARGE UNITS -
with front discharge-
The majority of the heat discharges out the front. A
minimal amount of heat will pass through the side ducts.
These duct runs need to be as short as possible. An
optional air diverter with 55° angle vanes can be added to
front discharge opening to direct heat fore or aft in the
trailer.
8012-II 7912-II 7916-II 7920-II - FRONT DISCHARGE UNITS -
no ducts allowed on 8012-II
The heat discharges only through the front. The optional
air diverter noted above can be added to front discharge
opening to direct heat for or aft in the trailer.
RETURN AIR REQUIREMENTS
Return air is provided through the front door grill - approximately 33 square inches (213cm2). If the furnace is
installed at zero clearance, an additional 16 square inches (103cm2) of return air must be provided to the blower
wheel side of the furnace.
Duct #1
Duct #2
Front
Discharge
OPEN
Duct #1
Duct #2
Front
Discharge
CLOSED
Front
Discharge
OPEN
MODEL DESCRIPTION 79 I6-II DC 6 A
Model & Rate Input
79 -12-II = 12,000
16-II = 16,000
20-II = 18,000
80 -12-II = 12,000
Valve Setting & Power Usage
DC = Direct current 12 volts
Fitting Size Gas
6 = 3/8˝ flare
Venting or Ducting Options
A = vent length 4˝ approximate
B = vent length 8˝ approximate
C = vent length 12˝ approximate
5
79-II Directional Air Box Insert (PN 36959)
An air discharge diverter is now available for all 79 series furnaces. This insert has fins that are set at a 55
degree angle. This will allow you to direct the heat fore or aft in the camper easier.
1. Remove the front grill
of the furnace.
2. Follow the shutdown procedure instructions
affixed to the furnace.
3. Remove the sheet metal screw that holds
the circuit board plate to the air box. Retain
to fasten the Air Box Insert to the bottom of
the air box.
4. Install the Air Box Insert into the air box
paying particular attention to the direction
where you would like the warm air diverted.
Make sure the two holes in the Air Box
Insert line up with the existing holes in the
air box.
5. Fasten the Air Box Insert to the top of the
air box using a 1/4˝ long #6 sheet metal
screw. Fasten the bottom of the Air Box
Insert and the circuit board plate to the
bottom of the air box using the screw
removed in step 3.
6. Follow the lighting instructions to place the
furnace in operation.
7. Replace the front grill on the furnace.
6
85 Series Model Identification
MODEL DESCRIPTION 85 I6-II DC LP 6 SB w/o Therm
Model
BTU/Hr Rate (Input)
16-IV = 16,000
20-IV = 20,000
25-IV = 25,000
31-IV = 30,000
35-IV = 34,000
Voltage DC
Type Gas
LP = Propane
Gas connection size
6 = 3/8” Flare
Options
SB = Side/Bottom discharge
V = Ventilator
SB FIP = SB w/field plug
Thermostat
with thermostat
w/o thermostat
NOTE: The new 85-IV series furnace, through some design changes is quieter than the previous 85 series. It
incorporates some plastic components in the blower housing area to accomplish this. These components
are not retro-fittable to other 85 series furnaces.
Applications - This unit is typically installed in travel trailers, 5th wheels and motor homes.
Installation - This series of furnace can be installed either vertically or horizontally. If installed vertically, the exhaust port must be
located at the bottom. Extra care must also be given in sealing this type of installation. Consult the installation manual for
details.
Heat Outlets - This furnace can be bottom discharged to a hard duct system, soft ducted out the back to a discharge plate
into a hard duct system or completely soft ducted from a combination of the seven outlets located on both sides and back
of the furnace. Refer to the installation manual for the ducting requirements of the specific model of furnace.
Serviceability - This entire furnace is serviceable without removing it from the RV. Therefore, there is no need to bench test it. All
components are accessible by merely opening the access door. We strongly recommend trouble-shooting the furnace while it is
installed in the RV.
Power Consumption - This furnace is designed to draw between 4.6 and 9.8 amps depending on the model of the furnace.
Refer to the furnace specification decal when trouble-shooting its electrical system.
7
89 Series Model Identification
MODEL DESCRIPTION 89 35 DC LP 6
Model
BTU/Hr Rate (Input)
35 = 35,000
40 - 40,000
Voltage
DC = direct current 12 Volts
AC = 120 Volts(120 VAC)
Type Gas
LP = Propane
LC = set at factory for propane but field
changeable to natural
NC = set at factory for natural but field
changeable to propane
Gas connection size
6 = 3/8” Flare
Applications - This unit is typically installed in large travel trailers, 5th wheels, motor homes and park model trailers.
Installation - The 89 series furnace must only be installed horizontally.
Options - As the chart above indicates, this furnace can be purchased to operate on 12VDC or 120VAC with LP gas or Natural
gas. Natural gas option is only available on AC models.
Heat Outlets - This furnace can be bottom discharged to a hard duct system, soft ducted out the back to a discharge plate
into a hard duct system or completely soft ducted from a combination of the six outlets located on both sides and back of
the furnace. Refer to the installation manual for the ducting requirements of the specific model of furnace.
Serviceability - This entire furnace is serviceable without removing it from the RV. All components are accessible by merely
opening the access door. We strongly recommend trouble-shooting the furnace while it is installed in the RV.
Power Consumption - The DC version of this furnace is designed to draw approximately 11.0 amps. This is important when
trouble-shooting the motor of this furnace.
2-stage Model Identification
MODEL DESCRIPTION 23 34 DC LP 6 BP
Model
BTU/Hr Rate (Input)
Low 23 = 23,000
High 34 = 34,000
Voltage
DC = direct current 12 Volts
Type Gas
LP = Propane
Gas connection size
6 = 3/8” Flare
8 = 1/2” Flare
Packing
SP = Single Pack
BP = Bulk Pack (layers of 4)
8
Wiring Diagram for 7900-II / 8000-II
Black
Red
Black
White
Relay Red
Black
Red
Black
High Tension
White
White
Red +12V DC
Neg.
Red
5179 Yellow
White
GROUND
MOTOR
ELECTRODES
VALVE
LIMIT
SWITCH
DSI
CONTROL THERMOSTAT
CIRCUIT BREAKER
On/Off Switch
SAIL
SWITCH
Black
With Blower Control Ignition Board REMOTE Sense Wiring
If any original wire has to be replaced,
it must be replaced with type 105° C
or its equivalent.
IMPORTANT
NOTE: The ON/OFF switch, located in line with
the gas valve, is not used when a
combination circuit breaker and ON/OFF
switch is used.
Black
Red
Blue
Black
White
Red
PWR BLO
Black
Red
Black
High Tension
White
White
Red +12V DC
NEG
Red
5179 Yellow
White
GROUND
MOTOR
ELECTRODE
VALVE
LIMIT
DSI
CONTROL
THERMOSTAT
CIRCUIT BREAKER
On/Off Switch
SAIL
SWITCH
White
Black
Red
Black
White
Relay Red
Black
Red
Black
High Tension
White
White
Red +12V DC
Neg.
Red
5179 Yellow
White
GROUND
MOTOR
ELECTRODES
VALVE
LIMIT
SWITCH
DSI
CONTROL THERMOSTAT
CIRCUIT BREAKER
On/Off Switch
SAIL
SWITCH
LOCAL Sense Wiring
NOTE: The ON/OFF switch, located in line with
the gas valve, is not used when a
combination circuit breaker and ON/OFF
switch is used.
9
COMPRESSOR / COMPRESSEUR
HIGH FAN / VENTILATEUR HAUT
LOW FAN / VENTILATEUR BAS
115VAC NEUTRAL / 115 VCA NEUTRE
GROUND / TERRE
MED FAN*/ VENTILATEUR MOY*
123456
1
123
21234
WHT / BLANC
RED / ROUGE
BLK / NOIR
YEL / JAUNE
WHT / BLANC
GRN / VERT
21
4
COMPRESSOR
COMPRESSEUR MOTOR
MOTEUR
REV. VALVE / SOUPAPE D’INVERSIO
12
FREEZE / GEL
RJ45
COM
CABLE/CÂBLE
RJ45
COM
CABLE/CÂBLE
SENSORS / CAPTEURS
REMOTE /
A DISTANCE
RED – 12VDC + + / ROUGE – 12VCD +
BLACK / NOIR
BLK
NOIR
VIO / VIO
YEL / JAUNE
RED / ROUGE
RED / ROUGE
BLK / NOIR
DOMETIC
HEAT STRIP RVP DOMETIC
AND CARRIER
HEATSTRIP 115V LINE
HEATSTRIP 115V NEUTRAL
115VAC NEUTRAL
REVERSING VALVE
COMPRESSOR
HEATSTRIP
HIGH FAN
LOW FAN
GROUND
BLANK
115 VAC NEUTRAL
COMPRESSOR
HIGH FAN
LOW FAN
115VAC NEUTRAL
GROUND
MED FAN*
GRY / GRIS
BLK
NOIR GRN
VERT
GRN / VERT
GRN
115 VAC LINE / Câble 115 VCA
115 VAC NEUTRAL / 115 VCA NEUTRE
115 VAC GROUND / 115 VCA TERRE
123 123456 123456789
BLACK / NOIR
WHT / BLANC
GRY / GRIS
BLACK – 12VDC Ground Terre / NOIR – 12VCD Terre
VIOLET – AGS / VIOLET – AGS
YELLOW – Loadshed / JAUNE – Délestage
BLUE / BLEU 2-STG or STD
BROWN / MARRON
AMBIENT /
AMBIANT
BLK / NOIR
COMPRESSOR
COMPRESSEUR HEAT STRIP
BANDE CHAUFFANTE
Med. Fan on
Dometic A/C
Rev. Valve on
Dometic HP
and Carrier HP
*
DOMETIC
BANDE CHAUFFANTE RVP DOMETIC ET
CARRIER
CÂBLE DE BANDE
CHAUFFANTE 115V
BANDE CHAUFFANTE
115V NEUTRE
115 VCA NEUTRE
SOUPAPE D’INVERSION
COMPRESSEUR
BANDE CHAUFFANTE
VENTILATEUR HAUT
VENTILATEUR BAS
TERRE
VIDE
115 VCA NEUTRE
COMPRESSEUR
VENTILATEUR HAUT
VENTILATEUR BAS
115 VCA NEUTRE
TERRE
VENTILATEUR MOY*
Ventilateur moy sur
climatiseur Dometic
Soupape d’inversion
sur HP Dometic et
Carrier
*
BI-ÉTAGÉ ou STANDARD
CONNECTS FOR
CARRIER PRODUCT
10
IMPORTANT: If any original wire has
to be replaced, it must be replaced
with type 105° C or its equivalent.
Terminal Block on 85 Models only.
RED
BLACK
YELLOW BLUE
RED
BLACK
HIGH TENSION
+ 12V DC
NEG
RED
YELLOW
ELECTRODE
BLACK
VALVE RED 1
4
2
5
3
6
1
4
2
5
3
6
+THERMO
MOTOR
CIRCUIT
BREAKER
IGNITION
CONTROL
BLOPWR
SAIL
SWITCH
WHITE
LIMIT
SWITCH
WHITE
BLUE
BLUE
BLUE
GROUND
BLUE
THERMOSTAT
ON
OFF
ON/OFF
SWITCH
+12v LS SS
TH
CB
ICB
Pwr
Blw
TH
CB = Circuit Breaker
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
+12v GND
FS
HV
VC VC
EL
LADDER DIAGRAM GND
SS = Sail Switch
TH = Thermostat
LS = Limit Switch
TR = Thermo Relay
VC = Valve Control
PS = Power Switch
MOT
NOTE: In some installations, the Power Switch (PS)
may control the air conditioning system
thermostat function.
PS
THERMO
RED
BLACK
YELLOW BLUE
RED
BLACK
HIGH TENSION
+ 12V DC
NEG
RED
YELLOW
ELECTRODE
BLACK
VALVE RED
+THERMO
MOTOR
CIRCUIT BREAKER/
ON/OFF SWITCH
IGNITION
CONTROL
BLOPWR
SAIL
SWITCH
WHITE
LIMIT
SWITCH
WHITE
BLUE
BLUE
GROUND
BLUE
THERMOSTAT
+12v LS SS
TH
CB
ICB
Pwr
Blw
TH
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
SS = Sail Switch
+12v GND
FS
HV
VC VC
EL
LADDER DIAGRAM GND
TH = Thermostat
LS = Limit Switch
TR = Thermo Relay
VC = Valve Control
PSCB = Power Switch/
Circuit Breaker
MOT
NOTE: In some installations, the Power Switch (PS)
may control the air conditioning system
thermostat function.
PS
THERMO
WITHOUT DOOR, but with Blower Control Ignition Board
WITH DOOR and Blower Control Ignition Board
85-III Local Sense
Red
Relay
Yellow
Blue
Red
Yellow
High Tension
+12V DC
Neg.
Red
Yellow
Single Sense
Electrode Yellow
Valve
Red 1
2
3
4
5
6
1
2
3
4
5
6
Motor
Circuit breaker ON/OFF switch
Ignition control
Sail
switch
White
Limit
switch
White
Blue
Yellow
Red
Ground
White
Switch
Thermostat
85-IV Local Sense
RED
RELAY
YELLOW
BLUE
RED
BLACK
HIGH TENSION
+ 12V DC
NEG
RED
YELLOW
ELECTRODE
BLACK
VALVE RED 1
4
2
5
3
6
1
4
2
5
3
6
+THERMO
MOTOR
CIRCUIT
BREAKER
IGNITION
CONTROL
SAIL
SWITCH
WHITE
LIMIT
SWITCH
WHITE
BLUE
YELLOW
RED
GROUND
BLUE
THERMOSTAT
ON
OFF
ON/OFF
SWITCH
THERMO
RED
85 Series Wiring Diagrams
11
85 Series Wiring Diagrams
Red
Relay
Red
Blue
Red
Black
Yellow
High Tension
+12V DC
Neg.
Red
Yellow
Electrode
Yellow
Black Valve
Red 1
2
3
4
5
6
1
2
3
4
5
6
+ Thermo
Thermo
Motor
Circuit breaker
Ignition control
Sail
switch
White
Limit
switch
White
Blue
Yellow
85-III Remote Sense
power
valve
sensor
valve
+12 VDC red 11
22
33
44
55
66
12 VDC yellow
thermo blue
thermo blue sail switch
circuit
breaker
motor
limit
switch
relay
ground
85-II
sail switch
circuit
breaker
relay
motor
limit
switch
power
valve
sensor
valve
+12 VDC red 11
22
33
44
55
66
12 VDC yellow
thermo blue
thermo blue
85-I
If any original wire has to be replaced,
it must be replaced with type 105° C
or its equivalent.
IMPORTANT
NOTE: The ON/OFF switch, located in line with
the gas valve, is not used when a
combination circuit breaker and ON/OFF
switch is used.
12
Wiring Diagram for 8900-III
DC Wiring Diagram
+12 VDC red
Circuit breaker
ON/OFF Switch
+Thermo blue
-12 VDC yellow
Thermo blue
red
yellow
blue motor relay
red
blue
sail
switch
limit
switch
blue
red
power
valve
gnd
high voltage
yellow 1 2
gas 3 4
valve
IMPORTANT:
If any original wire has to be replaced,
it must be replaced with type 105° C
or its equivalent.
red
yellow
Supply LeadsFurnace Wiring
(+) 12 volt DCto(+) 12 volt DC (red wire)
(-) 12 volt Dto(-) 12 volt DC (yellow wire)
thermostattothermostat (blue wires)
RELAY
YELLOW
RED
GREEN
HIGH TENSION
RED
YELLOW
ELECTRODE
VALVE
MOTOR
CIRCUIT
BREAKER
IGNITION
CONTROL
SAIL
SWITCH
BLUE
LIMIT
SWITCH
BLUE
+ THERMO BLUE
GROUND
THERMOSTAT
OFF
ON
BLUE
GREEN
GREEN
BLACK
BLACK
BLACK
11
22
33
YELLOW
WHITE
BLACK
WHITE
-THERMO BLUE
WHITE WHITE
BROWN
AC CAPACITOR
MOTOR RUN
120 VAC GREEN
120 VAC BLACK
120 VAC WHITE
TRANSFORMER
BLACK
BLUE
RED
YELLOW
HIGH TENSION
+ 12V DC
NEG
RED
YELLOW
ELECTRODE
YELLOW
VALVE RED 1
4
2
5
3
6
1
4
2
5
3
6
+THERMO
MOTOR
CIRCUIT
BREAKER
IGNITION
BOARD
BLOPWR
SAIL
SWITCH
BLUE BLUE
LIMIT
SWITCH
WHITE
BLUE
YELLOW
GROUND
THERMOSTAT
ON
OFF
ON/OFF
SWITCH
THERMO
DC Wiring Diagram AC Wiring Diagram
RED
BLACK
BLUE
RED
YELLOW
HIGH TENSION
+ 12V DC
NEG
RED
YELLOW
ELECTRODE
YELLOW
VALVE RED 1
4
2
5
3
6
1
4
2
5
3
6
+THERMO
MOTOR
CIRCUIT
BREAKER
IGNITION
BOARD
BLOPWR
SAIL
SWITCH
BLUE BLUE
LIMIT
SWITCH
WHITE
BLUE
YELLOW
GROUND
THERMOSTAT
ON/OFF
SWITCH
THERMO
DC Wiring Diagram
RED
WITHOUT DOOR
WITH DOOR WITH DOOR
RED
RED
13
WIRING DIAGRAM FOR 2-STAGE FURNACE
Two Stage Furnace
Models 1522 & 2334
WITH DOOR AND WITHOUT DOOR
Two Stage Furnace
Model 2540
WITH DOOR AND WITHOUT DOOR
1
6
+12
VDC
–12
VDC
54
Thermostat
Dual
Cont. Ignition
Control
5ON-12
Low
Valve
Brown
Green
Yellow
Geen
Yellow
Red
Red
Red
Red
Green
Yellow
GND
White
Black
White Blue
Blue
Blue
LS SS
PS
MOT
C.B.
Orange
Main
Valve
GV
Redundant
Valve
321 23456
Case
Bulk-
head
CB = Circuit Breaker
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
SS = Sail Switch
LS = Limit Switch
PS = Power Switch
NOTE: The Power Switch (PS)
does not control the air
conditioning system
thermostat function.
HV EL
1
6
+12
VDC
–12
VDC
54
Thermostat
Dual
Cont. Ignition
Control
5ON-12
Low
Valve
Brown
Green
Yellow
Geen
Yellow
Red
Red
Red
Red
Green
Yellow
GND
White
Black
White Blue
Blue
Blue
LS SS
PS/CB
MOT
Orange
Main
Valve
GV
Redundant
Valve
321 23456
HV EL
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
SS = Sail Switch
LS = Limit Switch
PS/CB = Power Switch/
Circuit Breaker
NOTE: The Power Switch (PS)
does not control the air
conditioning system
thermostat function.
1
6
+12
VDC
–12
VDC
54
Thermostat
Dual
Cont. Ignition
Control
5ON-12
Low
Valve
Brown
Yellow
Geen
Yellow
Red
Red
Red
Red
Green
Yellow
GND
White
Black
White Blue
Blue
Blue
LS SS
PS
MOT
C.B.
Orange
Main
Valve
GV
Redundant
Valve
321 23456
Case
Bulk-
head
CB = Circuit Breaker
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
SS = Sail Switch
LS = Limit Switch
PS = Power Switch
NOTE: The Power Switch (PS) does not
control the air conditioning system
thermostat function.
HV EL
1
6
+12
VDC
–12
VDC
54
Thermostat
Dual
Cont. Ignition
Control
5ON-12
Low
Valve
Brown
Yellow
Geen
Yellow
Red
Red
Red
Red
Green
Yellow
GND
White
Black
White Blue
Blue
Blue
LS SS
PS/CB
MOT
Orange
Main
Valve
GV
Redundant
Valve
321 23456
HV EL
GND = Ground
GV = Gas Valve
HV = High Voltage
EL = Electrode
MOT = Blower Motor
SS = Sail Switch
LS = Limit Switch
PS/CB = Power Switch/Circuit Breaker
NOTE: The Power Switch (PS) does not
control the air conditioning system
thermostat function.
2-Stage Furnace Diagnostics
NUMBER OF LED FLASHES DIAGNOSTIC INFORMATION LOCKOUT
1 Low Input voltage SOFT
2 Ignition Failure SOFT
3 Open High Limit SOFT
4 Stuck Sail Switch HARD
5 Module Fault HARD
NOTE:A SOFT lockout is a condition that is timed and will make additional
attempts to correct the problem. A HARD lockout requires reset of
the thermostat or turning the power switch off then back on.
DIAGNOSTIC CHART
A diagnostic LED is located inside the exterior access cover
on the outside edge of the horizontal (2) stage control
board. The following graph defines the codes.
An Excalibur 2-Stage furnace must use an
Atwood Digital Thermostat.
14
ENGLISH, FRANCAIS (et Canada) •Installation •Operation
Effective 6/19/02
MPD 38285
hydro flame
TM
Model 1H2C
Digital Thermostat
FOR STANDARD FURNACES
&A/C SYSTEMS
SPECIFICATIONS
Operating Voltage .............. 9VDC to 18VDC
Current Consumption at 12VDC ...... 100mA
Operating Temp..................... -40F to +185F
Room Temp. Range ................ +55F to +90F
Room Temp. Display Range .... +35F to +99F
Thermostat Accuracy ........................ +/- 1F
Switching Capability A/C............up to 24 VAC
(max. 2 AMPs)
THERMOSTAT INSTALLATION
Thermostat is very sensitive. HANDLE
WITH CARE AT ALL TIMES.
Locate thermostat 48˝ to 54˝ above
floor on an INTERIOR wall. Pick a dry
area where air circulation is good.
EXTERIOR wall location must have a
3/4˝ spacer between thermostat and
exterior wall.
1. Be sure all electrical power has
been disconnected from the air
conditioner, furnace and the
power supply.
2. Do not install the thermostat
where there are unusual heating
conditions: such as direct
sunlight, heat producing
appliances (television, radio, wall
lamp, etc.) or a furnace or air
conditioner supply register.
3. ATTACHING THE WALL THERMOSTAT.
Separate the thermostat body
from the sub-base by gently
squeezing the top and bottom,
connecting wiring per
requirements. Attach thermostat
sub-base to the wall at desired
mounting location.
THIS THERMOSTAT HAS BEEN DESIGNED TO OPERATE STANDARD AIR CONDITIONING UNITS IN CONJUNCTION WITH A RV FURNACE.
COOL FAN
OFF HEAT M
Display
System Switch
Temperature Set
Mode Set
7.5 VDC ANALOG A/C SYSTEMS (DOMETIC®)
THERMOSTAT WIRE FROM FURNACE WIRE FROM A/C
TERMINAL # (L-R)FUNCTION FUNCTION
1-12vdc ground
2 & 4 7.5 vdc
3+12vdc
5Compressor
6High Fan
7Low Fan
8Furnace Control
12 VDC ANALOG A/C SYSTEMS (RVP®)
THERMOSTAT WIRE FROM FURNACE WIRE FROM A/C
TERMINAL # (L-R)FUNCTION FUNCTION
1-12vdc ground
2not used not used
3 & 4 +12vdc
5Compressor
6High Fan
7Low Fan
8Furnace Control
SLIDE SWITCH SCROLL ORDER OF
LEFT RIGHT DISPLAYED MODES OPERATION
COOL OFF HEAT FAN Furnace Operation
•HI Furnace cycles to satisfy set point.
COOL OFF HEAT FAN Air Conditioner Operation
•AU Air conditioner automatically switches compressor and high and
low speed fan when cycling to satisfy set point.
•HI Air conditioner compressor and high speed fan cycle to satisfy
set point.
•LO Air conditioner compressor and low speed fan cycle to satisfy
set point.
COOL OFF HEAT FAN Fan Operation
•HI Air conditioner fan runs at high speed to circulate air.
•LO Air conditioner fan runs at low speed to circulate air.
COOL OFF HEAT FAN Off
•OF No operation occurs.
WIRING REQUIREMENTS FOR ATWOOD THERMOSTAT
FURNACE
12 VDC
SOURCE
+
7.5V
HI FAN
6
LOW FAN
7
COMPRESSOR
5
2
8
3
1
FURNACE
+
YGH GL B
HI FAN
6
LOW FAN
7
COMPRESSOR
5
12 VDC
SOURCE
8
3
1
CONNECT 4 TO 3
WITH JUMPER CONNECT 4 TO 2
WITH JUMPER
15
ENGLISH, FRANCAIS (et Canada) •Installation •Operation
Effective 2/4/02
LITERATURE NUMBER MPD 38914
hydro flame
TM
Model 2H2C
Two Stage Furnace
Digital Thermostat
FOR TWO STAGE FURNACE
1
12VDC
Ground
3
+12VDC
2
7.5V
Screw Mounting Holes
4
RELAY
COM
*
5
A/C
COM-
PRESSOR
6
A/C
HI
FAN
7
A/C
LOW
FAN
8
TH FROM
FURNACE
(CLIM) COOL FAN (VENTIL.)
(OFF) OFF HEAT (CHAUFFAGE) M
Display
System Switch
Temperature
Set
Mode
Set
Specifications Operating Voltage ...................... 9VDC to 18VDC
Power Consumption ................................ 100mA
Operating Temperature .................. -40F to +185F
Room Temperature Range .............. +55F to +90F
Room Temperature Display Range .. +35F to +99F
Thermostat Accuracy ................................ +/- 1F
System Slide Switch SCROLL ORDER OF
LEFT RIGHT DISPLAYED MODES OPERATION
COOL OFF HEAT FAN Scroll Order of Displayed Modes Furnace Operation
•AU Furnace automatically switches between high and low BTU valve and high
and low speed fan when cycling to satisfy set point.
•HI Furnace high BTU valve and high speed furnace fan cycle to satisfy set point.
•LO Furnace low BTU valve and low speed furnace fan cycle to satisfy set point.
•HF Furnace fan runs at high speed to circulate air. Air conditioner fan does not run.
•LF Furnace fan runs at low speed to circulate air. Air conditioner fan does not run.
COOL OFF HEAT FAN Scroll Order of Displayed Modes Air Conditioner Operation
•AU Air conditioner automatically switches compressor and high and low speed fan when
cycling to satisfy set point.
•HI Air conditioner compressor and high speed fan operate to satisfy set point.
•LO Air conditioner compressor and low speed fan operate to satisfy set point.
•HF Air conditioner fan runs at high speed to circulate air. Furnace fan does not run.
•LF Air conditioner fan runs at low speed to circulate air. Furnace fan does not run.
COOL OFF HEAT FAN Scroll Order of Displayed Modes Fan Operation
•HI Air conditioner fan and furnace fan run at high speed to circulate air.
•LO Air conditioner fan and furnace fan run at low speed to circulate air.
COOL OFF HEAT FAN Scroll Order of Displayed Modes Off
•OF No operation occurs.
THERMOSTAT INSTALLATION
Thermostat is very sensitive. HANDLE WITH CARE AT ALL TIMES.
Locate thermostat 48˝ to 54˝ above floor on an INTERIOR wall.
Pick a dry area where air circulation is good. EXTERIOR wall
location must have a 3/4˝ spacer between thermostat and
exterior wall.
1. Be sure all electrical power has been disconnected from
the air conditioner, furnace and the power supply.
2. Do not install the thermostat where there are unusual
heating conditions: such as direct sunlight, heat
producing appliances (television, radio, wall lamp, etc.)
or a furnace or air conditioner supply register.
3. ATTACHING THE WALL THERMOSTAT.Separate the thermostat
body from the sub-base by gently squeezing the top and
bottom. Pull wires through access hole in base plate.
Attach thermostat sub-base to the wall at the desired
mounting location. Mount the sub-base to the wall before
connecting the wires.
THIS THERMOSTAT HAS BEEN DESIGNED TO OPERATE STANDARD AIR CONDITIONING UNITS IN CONJUNCTION WITH AN EXCALIBUR 2-STAGE FURNACE.
*Note: Move jumper
from positions 3 and 4 to
positions 2 and 4 for use
with some 7.5V switching
analog relay kits.
16
Sequence of Operation - DC Models (STANDARD ONE-STAGE)
The ON/OFF switch allows power to pass to the circuit
breaker and the thermostat.
The thermostat controls the operating circuit to the
furnace by reacting to room temperature. When room
temperature is below the thermostat set point, the
contact closes to allow current to flow to the relay.
The circuit breaker limits amperage draw of motor.
The relay allows current to pass to the motor by
closing a switch within the relay. Voltage from the
thermostat activates the relay to turn the fan on. This
takes 1-25 seconds.
Current flows to the motor to operate the blower. One
end of the motor shaft is for the circulating air wheel
and the other side is for the combustion air wheel.
Circulating air blows against the sail switch and
closes the contacts, completing the circuit. The sail
switch is a safety device that insures air flow before
ignition.
The limit switch is a safety device that protects the
furnace from over heating. The contacts in the limit
switch open at a given temperature setting, shutting
off power to the electronic ignition system that
controls the gas valve.
As power is applied to the circuit board, the system
does the following:
1. A timing circuit allows the blower to purge the
chamber (15-17 seconds)
2. The board supplies current to the gas valve and
causes it to open.
3. As the valve opens, the board sends a high voltage
spark to the electrode at the burner. The board
detects the presence of a flame. If the flame is not
sensed after approximately six seconds, the board
will lock out (three try for ignition, one hour lockout
and then three retry), shutting off power to the
valve.
4. If the system does not ignite and the thermostat
remains closed, the blower will remain on until the
thermostat is reset manually.
When the thermostat senses the desired room air
temperature, the contacts open, removing power from
the ignition system and shutting off the gas valve. The
blower runs until the relay opens the circuit, shutting
off current to the motor.
WARNING
FURNACE PRODUCES HIGH TEMPERATURE
• Locate furnace out of traffic and away from furniture and
draperies.
• Do not touch or put combustibles near appliance. Hot surface
temperature may occur.
• Supervise young children in the same room as the furnace.
• Do not place clothing or flammable materials on or near the furnace.
17
The digital thermostat controls the operating circuit to the furnace by
reacting to room temperature. When the room temperature is below the
thermostat set point by 2°F a heat demand signal will be sent to the
controller module (see MPD 38463).
The ON/OFF switch is an agency safety power shut off to the furnace
ignition and gas valve systems.
The circuit breaker limits amperage draw of the motor.
Current flows to the controller module and during the first seconds the
micro-processor confirms inputs and verifies correct operation of safety
redundancies. This module will perform the following diagnostic checks of
the system.
a. Sail Switch is open
b. Internal Microprocessor faults
c. Voltage inputs
d. Ignition
e. Open Limit Switch
In the event of a failure an LED on the controller module will flash a code.
See chart.
The motor receives current from the controller module and will run at high
speed or low speed depending on the demand signal the digital
thermostat sends to the controller module. One end of the motor shaft is
for the circulating air wheel and the other end is for the combustion air
wheel.
Circulating air blows against the sail switch and closes the contacts,
completing the circuit. The sail switch is a safety device that insures air
flow before ignition.
The limit switch is a safety device that protects the furnace from over
heating. the contacts in the limit switch open at a given temperature
setting, shutting off power. This activates the open limit switch diagnostics
and makes the LED on the controller module to flash and shuts down the
gas valve. See chart.
As power is applied to the circuit board, the system does the following:
a. timing circuits allows the blower to purge the heat chamber for 15
seconds.
b. current is supplied to the gas valve and causes it to open to high
burn. (The controller module activates the low burn operation on the
valve.)
c. as the valve opens, the ignition module sends a high voltage spark
to the electrode at the burner. The ignition module detects the
presence of a flame. If the flame is not sensed after 7 seconds of
sparking a signal is sent to the controller module that there is no
ignition and shuts off the valve. After another 25 second purge, it
will try again. After a third try, the controller will go into “soft”
lockout, timing for one hour and the diagnostic LED will flash a
code, see chart. After the timed hour, the controller will initiate (3)
more tries for ignition. If there is no ignition, the timing sequence
begins again.
d. If the system does not ignite and the thermostat is still calling for a
heat demand, the blower will run for 90 seconds as a post purge
then shut off.
Thermostat
Breaker
10 VDC Motor
Sail
Switch
Limit
Switch
Circuit Board
Electrode
2-Stage
Valve
+12VDC
Electrical
Switch
COOL FAN
OFF HEAT M
- 12VDC
Controller
Module
Sequence of Operation - DC Models
2-Stage Excalibur™Furnace ONLY
When the thermostat senses the desired room
air temperature, a signal is sent to the controller
module to shut down operation of the gas valve
and run the blower for 90 seconds as a post
purge of heat from the furnace heat chamber.
18
Sequence of Operation
Pilot Models
The thermostat controls the operating circuit to the
furnace by reacting to room temperature to open and
close a set of contact points which allows current to
flow to the relay.
The relay receives the current and allows current to pass
through to the circuit breaker by closing a switch within
the relay. This is done by a heater coil within the relay
which actuates a bi-metal disc closing the relay circuit.
The circuit breaker is placed in line to monitor the Amp
draw of the motor. It is an overload and safety protector
for the motor.
The current then flows to the motor and allows the
blower to operate. One end of the motor shaft drives the
circulating air wheel and the other end of the motor shaft
drives the combustion air wheel that delivers the
required air to the burner for combustion.
As the circulating air wheel comes up to speed, it blows
against the sail switch completing the circuit. The sail
switch is placed into the system as a safety to prove
there is adequate air for combustion.
The limit switch is an in line safety device which protects
the furnace from any over heating conditions. The
contacts in the limit switch open at a given temperature
setting, shutting off power to the valve.
The next section of operation is controlled by the valve
and pilot. Once the power is applied to the valve, the
following steps are:
1. Set gas valve knob to the pilot setting to light the
pilot.a. light pilot.
2. Set gas valve knob to the ON position for burner
operation.
3. While ON stand by, if the pilot goes out and the
thermostat closes, the blower will come on, but the
valve will remain closed. At this time, the pilot must
be relit for burner operation.
Note: The blower will remain running until the
thermostat contact opens.
As the thermostat senses the room air temperature, the
contacts will open removing power from the valve which
will shut off the gas. The blower will remain on until the
heater coil within the relay cools and the relay opens
and stops the current flow to the motor.
A
B
C
D
E
F
A - Thermostat
B - Relay
C - Breaker
D - Motor
E - Sail Switch
F - Limit
G - Gas Valve
H - Pilot Assembly
G
H
19
Sequence of Operation - AC Models
Operating Circuitry 24 VAC
The transformer receives 120 VAC which it converts to
24 VAC for the operating circuitry.
The thermostat controls the operating circuit to the
furnace by reacting to room temperature. When room
temperature is below the thermostat set point, the
contacts close to allow current to flow to the relay.
The relay receives 24 VAC and energizes a heater coil
within the relay. This activates a bimetal disc which
closes the relay circuit. This takes 17-20 seconds.
Once the relay circuit is closed, 120 VAC flows to the
motor and allows the blower to run. One end of the
motor is for the circulating air wheel and the other end
is for the combustion air wheel.
Circulating air blows against the sail switch and closes
the contacts, completing the circuit. The sail switch is a
safety device that insures air flow before ignition.
The limit switch is a safety device that protects the
furnace from overheating. The contacts in the limit
switch open at a given temperature setting, shutting
off power to the electronic ignition system that
controls the gas valve.
As power is applied to the electronic ignition circuit
board, the system does the following:
1. A timing circuit allows the blower to purge the
chamber (15-17 seconds.
2. The board supplies current to the gas valve and
causes it to open. There is an electrical switch in
line to the valve to allow power to be manually
shut off to the valve. This switch must be on for
the furnace to operate. (Switch may be separate or
combined with circuit breaker).
3. As the valve opens, the board sends a high voltage
spark to the electrode at the burner. The board
detects the presence of a flame, if the flame is not
sensed after seven seconds, the board will lock
out, shutting off power to the valve.
4. If the system does not ignite and the thermostat
remains closed, the blower will remain on until the
thermostat is reset manually.
When the thermostat senses the desired room air
temperature, the contacts open removing power from
the ignition system and shutting off the gas valve. The
blower runs until the heater in the relay cools and
opens the circuit, shutting off current to the motor.
Thermostat
Circuit Breaker
or Breaker/
Switch Combination
Relay Motor
Sail
Switch
Limit
Circuit Board Electrical
Switch
(if applicable)
Electrode
Capacitor
Transformer
120 volts
AC input
power
Operating Circuitry 24 VAC Motor Circuitry 120 VAC
Black wire
120 VAC
WARNING
FURNACE PRODUCES HIGH TEMPERATURE
• Locate furnace out of traffic and away from furniture and
draperies.
• Do not touch or put combustibles near appliance. Hot surface
temperature may occur.
• Supervise young children in the same room as the furnace.
• Do not place clothing or flammable materials on or near the
furnace.
20
WARNING
CRITICAL INSTALLATION CRITERIA
• Do not install the furnace on material that restricts return air, such as carpet, or any soft
material, such as vinyl.
• Do not install furnace where clearance to combustibles cannot be maintained.
• Do not modify the furnace in any way.
• Do not alter the furnace for a positive grounding system.
• Do not HI-POT this furnace unless the electronic ignition system (circuit board) has been
disconnected.
• Do not use a battery charger to supply power to DC model furnace even when testing.
• Do not use 120 volt AC current with DC models.
• Do not use the furnace cabinet area as a storage compartment.
• Do not vent this furnace with a venting system serving any other appliance.
• Do not vent this furnace to an outside enclosed porch area.
• This furnace is not to be used for temporary heating of buildings or structures under
construction.
• Locate the furnace in an area that will not be blocked by snow.
• Locate the furnace in an area where the flue gases will not cause building materials to
degrade over time.
• Install furnace so electrical components are protected from water.
• Do not use closeable registers when minimum ducting cannot be maintained.
• Wire furnace direct to battery when possible.
• Use a minimum of 22 gauge wire for the thermostat.
• Use a minimum of 18 gauge wire to the furnace from power supply.
• Follow wiring color code exactly.
• Hold both fittings with a wrench when tightening gas connection.
• Always meet or exceed minimum duct requirements.
• Always meet minimum return air requirements.
• Isolate return air passage from range compartment.
WARNING
CARBON MONOXIDE POISONING
• Furnace must be installed and vented to these instructions.
• Improper installation, adjustment, alteration, service or
maintenance can cause injury or property damage.
• Negative pressure produced by the furnace can affect the
combustion air or venting of other appliances if installed in an
improper location.
For assistance or additional information, consult a qualified
installer, service agency or gas supplier.
21
ANNUAL PREVENTATIVE MAINTENANCE INSPECTION
The following preventive maintenance and safety checks should be performed by a qualified RV technician
once a year, or more, depending on the use of the furnace. Failure to properly maintain the furnace may void
the furnace warranty and can result in unsafe furnace operation. Preventive maintenance is not covered
under warranty.
WARNING
• Installation, repairs and preventative maintenance should be done by a qualified
service person only.
• The furnace should be inspected before use and at least annually by a qualified
service person.
• Frequent cleaning may be required due to excessive lint from carpeting, bedding
material, pet hair, etc. It is imperative that control compartments, burners and
circulating air passageways of the furnace be kept clean.
WARNING
• Label all wires prior to disconnection when servicing. Wiring errors can cause
improper and dangerous operation. Verify proper operation after servicing.
AIR WHEEL
The air wheel should be clean and clear of
obstructions. Starting the furnace with something in the
blower will damage the wheel, making replacement
necessary.
BURNER
The Burner requires no adjustments, but should be
inspected annually. Burners should be cleaned with a
wire brush to remove debris and corrosion build up.
COMBUSTION CHAMBER
Check the air intake and flue areas of the furnace for
internal obstructions, such as wasp or bird nests. The
life of the combustion chamber is a function of the
amount of time that the furnace has operated.
Therefore, it is essential to inspect the chamber for
cracks and holes. Have the chamber replaced if it has
any cracks or holes - this condition is not field
repairable. Chamber should be cleaned if obstructions
are present, by removing the chamber and flushing the
unit out with water.
CONTROL COMPARTMENT
Clean the control compartment to remove dirt and lint.
DUCTING
The heat ducts should be clean and clear of
obstructions. Check for proper duct connection. Any
ducts disconnected from the furnace or outlets must
be reattached.
GAS PRESSURE
Using a U-tube water manometer, with the furnace and
all of the gas appliances operating, the pressure should
be 11˝ W.C. (27mbar). Improper gas pressure can cause
the furnace to work inconsistently and create
unbalanced combustion.
GAS SUPPLY SYSTEM
Perform a pressure-drop test according to current ANSI
standards, to insure that there are no gas leaks.
GASKETS
Inspect all gaskets for tight seals. Do not reuse gaskets
- always replace with new.
GENERAL
Check that the physical support of the furnace is sound
and without sagging, cracks, gaps, etc.
MOTOR
The motor is lubricated and permanently sealed. It
requires no oiling. Brushes and armatures are not
replaceable.
RETURN AIR
The return air passage should be clean and clear of
obstructions and meet the minimum square inches as
specified in the installation instructions. Make sure
combustibles are not stored in the furnace
compartment. Filters are not recommended at these air
passages.
VENTING
After checking and clearing, if necessary, the draft cap
assembly must have the proper overlap between the
exhaust tube and the furnace chamber tube. Any air
leakage at these joints may cause improper
combustion. Draft cap assembly must overlap no less
than 1-1/4˝ (32mm), and be positioned against the door
screen for proper function.
VOLTAGE
Voltage should be between 10.5 and 13.5 VDC at the
furnace during operation. The power at the furnace
needs to be checked with each of the following power
sources when applicable: generator, battery, and
converter. Low voltage can cause the furnace to
overheat and cycle. High voltage can cause
unbalanced combustion, and excessive motor wear.
Note: To increase motor life the furnace should be
wired directly to the battery.
WIRE CONNECTIONS
Check the furnace for loose or disconnected wires.
22
Mechanical Thermostat
WHAT IS A THERMOSTAT?
• It is an ON/OFF switch controlled by a bi-metal coil which opens and closes an electrical contact by
sensing changes in the ambient temperature.
• With its contacts close, it supplies power to the time delay relay which in turn closes a contact that sends
power to the blower motor.
• Normally, the thermostat contacts are closed if the blower is running.
• The hydro flame thermostat is equipped with a heat anticipator which allows one to adjust the length of the
heating cycles. A furnace should cycle 5-6 times an hour.
a. The anticipator is set at 1.0 on all hydro flame thermostats. If you want to shorten the heating cycle,
move anticipator to a lower amp setting. You should not set lower than .48 which is the amperage rating
of the gas valve. Setting any lower could burn out the anticipator wire.
Note: Heat anticipator adjustments are not covered under warranty.
Heat/cool thermostats are being used in conjunction with air conditioners and our furnace. The warranty,
installation instructions and diagnostic information is provided by the manufacturer of the thermostat. However,
if you need to isolate a furnace problem or a dual thermostat problem, by-pass the furnace wires at the
thermostat. If the furnace ignites and heats, you have a thermostat problem. If the furnace does not run, the
problem is in the furnace, and you should consult the trouble shooting guides in the back of this manual.
THERMOSTAT LOCATION
• It should be on an inside wall 48˝-54˝ above the floor on an inside wall.
• It should not be near areas of extreme heat or cold.
• It should not be located directly across from a heat duct.
• If installed on an outside wall, a 3/4˝ spacer must be used behind legs of thermostat. This will allow the
thermostat to sense the air temperature and not the temperature of the wall.
• A minimum of 22 gauge wire should be used to connect the thermostat to the furnace. We recommend
18 gauge stranded wire.
Contacts
Adjustable
Heat Anticipator
Mounting Hole
Temperature Setting Level
Off Switch (Optional)
Anticipator setting
1.0
.20
.48
(valve
amperage)
23
CATALOG # ON BOARD ORDER-SERVICE PART NUMBER
05-159007-103........FENWAL, old style, uncovered, 12VDC36716
05-309017-153........FENWAL, uncovered, no legs, single try, 12VDC........................................36716
06-235132-001........FENWAL, single try, uncovered with legs, 12VDC....................................36716
05-505650-153........FENWAL, three trial, uncovered, micro-processor, 12VDC..........36716
05-299004-153........FENWAL, three trial, AC....................................................................................................................37515
............................CHANNEL, 2-Stage ignition board .................................................................................. 37965
............................CHANNEL, 2-Stage motor control board ................................................................ 37966
............................FENWAL, Relay on board.............................................................................................................. 36716
............................FENWAL, Relay on board with blower control retrofit kit.............. 38676
Thermostat
Breaker
Relay
Motor
Sail Switch
The circuit breaker is actually a re-settable heat sensitive device designed to
protect the blower motor. In a furnace, this heat evidences itself in the form
of an amp draw. Therefore, since there are different size motors, there are
different amperage ratings on circuit breakers. When replacing a breaker, do
so with similar amperage rated breaker.
The breakers used on our furnaces are externally mounted and are of a slow
blow style. This means that due to their location on our furnaces, the heat
of the furnace cannot affect their operation. Likewise, short amperage
spikes will not cause them to trip either. The motor will have to produce an
excessive and prolonged amperage draw to trip it.
When a circuit breaker trips, it does so because a problem exists. After re-
setting it, voltage and amperage draws should be taken to determine where the
problem is. These readings will determine if you have a power source, breaker or
motor problem.
On our 79 and 85 series furnaces we have two different types
of breakers. The earlier 79 and 85 models and all 89 models
used a rectangular slow blow breaker as pictured. Its sole
purpose was to protect the motor. On late model 79 and 85
models we started using a finger-size combination breaker
and on/off switch. Code required us to be able to shut the gas
off at the appliance when servicing it. This switch accomplishes
this by shutting off power to the blower motor, which in turn
prevents the gas ignition system from coming on.
Therefore, it is not only important to use the same amperage
rated breaker, but also the same style of breaker.
As stated earlier, there are different size motors as well. They
are different because they must be compatible with the
various BTU capacities. Each BTU of furnace requires a
specific motor RPM in order for proper ignition and
combustion to take place.
Since it is very important that the proper motor be used for a
specific model of furnace, you must identify if you have the
correct motor. To help identify a motor, a ‘PF’ number is
embossed in the metal housing of the motor. If you look at
the parts reference in the back of this manual, not only are
the proper hydro flame part numbers for the motor needed
on a specific furnace noted, but the corresponding ‘PF’
number is also shown.
A new motor has been introduced into all of the 85 and 89
series DC furnaces. This new motor design is hard-wired. As
a result the brushes are longer and should increase motor life
considerably. As a result, the motor kit will now contain a
motor mount bracket, the motor and installation instructions
and will add a little more time to the installation process.
However, these are the only motors that will be available as
replacements in the field.
The circuit board has three functions: create a spark, open the gas valve and lock-out when one
of the prior two functions do not occur during the ignition cycle. As long as the circuit board is
receiving the minimum micro-amps from the electrode assembly, it will not lock out. It has a 15
second ignition delay as well. This delay allows the furnace to purge any unburnt gas in the
combustion chamber before ignition occurs.
We have used two basic types of circuit boards. The first is the remote sense analog circuit board
that we have used for a number of years. It is a single trial ignition board that works in
conjunction with a dual or remote sense electrode (an electrode that has a separate
porcelain/sensing probe and a separate porcelain/sparking probe). The other board, which we have
only used for the past year or so is a micro-processor board. It is a three trial ignition board and
operates in conjunction with a single or local sense electrode (an electrode that has only one probe
that both sparks and senses).
Various versions of the 12VDC analog board have been used. The catalog numbers of those boards are noted below.
Fortunately, the local sense micro-processor board is the only one you will have to stock for replacement on a 12VDC furnace.
Plastic spacers will be provided
with the board so that it can be
mounted on metal surfaces that
you may encounter some-times
on various models of our furnace.
The only other circuit board that
you will have to stock is the AC
version.
Circuit Breaker & Motor
Circuit Boards
24
Relay
Sail Switch
Limit Switch
85-II, 89-I
Part # 35132
1/4˝ terminals
85-III, 85-IV, 1522, 2334
Part # 37022 (was 36176)
1/4˝ terminals
79-II, 89-II, 89-III, 2540
Part # 37021 (was 34781)
3/16˝ / 3/16˝ terminals
Thermostat Ground (-)
MotorCircuit
breaker (+)
Bimetal
Disc
Coil
L77 or L170 L54 L190
(170°F) (130°F) (190°F)
Markings
on Switch
This component is commonly referred to
as a time delay relay. The same relay is
used on the 7900, 8500 and 8900 series
furnaces.
FUNCTION - The relay has one primary
function.
• to purge the plenum of heat and the
chamber of any unburnt gases after each
heating cycle.
OPERATION - The motor voltage path of relay
is normally open. There should always be
voltage from the circuit breaker to the relay
terminal of the circuit breaker. There
should always be continuity between the
thermostat terminal connection and ground
terminal connection or the relay.
Only when the thermostat contacts are
closed is voltage supplied to the
thermostat terminal of the relay. This
voltage heats a coil in the relay body. In
approximately 20 seconds this heated coil
causes a bimetal disc to close. Voltage
now passes through the relay and on to the
motor, which in turn should allow the
furnace to ignite and start a heating cycle.
When a heating cycle is complete, the
contacts of the thermostat open and
voltage ceases to the heater coil of the
relay. In approximately 45 - 90 seconds,
the heater coil cools down, the bi-metal
disc opens and voltage ceases to the motor
as well.
AMP Draw - The relay should draw no
more than 1 amp. If the relay should draw
more than 1 amp, it will burn out the
anticipator.
The sail switch is an air proving device. It
is a safety component that will not let
ignition occur until it sees 75% of the
motor’s rpm’s. It insures that the
combustion wheel is rotating fast enough
so that there is a proper air and gas
mixture for smooth ignition.
There are different size sail switches. The
noticeable difference is the size of the
paddle on the switch. Each switch is
matched to the size of motor it must
respond to.
NOTE: All 85-IV use the same sail switch.
When the paddle of the switch is
depressed, there should be continuity
through the switch. If a sail switch needs to
be replaced, it should be replaced with the
exact same size. If a larger switch than the
original is used, it will probably not close
when the motor reaches 75% of its rpm’s
and therefore keep ignition from occurring.
The most common problems with these
switches are bent paddles, loose wire
connections or an obstruction between the
paddle and switch contact.
The limit switch is a very important safety device on a
furnace. The function of a limit switch is to protect the
furnace from overheating. These switches come in a variety
of temperature ratings and are located at critical locations
above the heat chamber on the various models of furnaces.
Therefore, it is very important that when one of these switches
is replaced, you do so with the properly rated switch.
Failure to do so could cause an unsafe condition with the
heating system. When in doubt as to whether you are using
the proper limit switch for a furnace, look at the temperature
at the base of the switch and match it to the temperature and
related switch noted below.
Part Number 36205 is a thermal cut-off and was a specific
safety component used on some 89-II furnaces. It was
located above the chamber and tripped in the event of a burn
through chamber.
25
Dual Solenoid Gas Valve
Burner Head, Electrode and Valve Assembly
Power from
Ignition Control
Shut off power
before servicing
(red wire) +12VDC
-12VDC
Local Sense
Electrode Remote Sense
Electrode
1/8"
1/4"
The burner head, electrode and gas valve on the late model 79 series
furnace are individually accessible. However, to service these same
components on the late model 85 and 89 series, remove the
complete assembly.
The different models and/or BTU ranges of furnaces use different
burner heads. These burners differ by the size of the top gas port
holes or the deflector that runs through the throat of the burner. If
the wrong one is used, it may cause an ignition, sooting or flame
sense problem.
When an electrode assembly is installed on a furnace, they will
already be in a fixed and predetermined position above the burner.
The only adjustment that you may need to do is on the sparking and
ground electrode points. This gap should be 1/8˝. However, when the
porcelain on an electrode assembly becomes cracked, it will not
function properly and will have to be replaced. When doing so, use
the proper electrode assembly for the model of furnace being
serviced.
There are only two versions of the solenoid valve available for the
models of furnaces noted above. These two valves are identical
except for the gas inlet porting on them (side or front). As stated
earlier in this manual though, the coils are what usually breakdown
but they are easily replaceable.
The different models and/or BTU ranges of furnaces use different
burner heads. These burners differ by the size of the top gas port
holes or the deflector that runs through the throat of the burner. If
the wrong one is used, it may cause an ignition, sooting or flame
sense problem.
We use a White Rodgers dual solenoid gas valve on all of our
furnaces. The valve requires a minimum of 10.5VDC in order to open
and when open, should draw no more than .48 amps.
Later model furnaces have an ON/OFF switch on the wire to the gas
valve. This replaces the manual shut-off that was used on earlier
model furnaces. You can now electrically shut off the gas to the valve
with this switch before servicing the furnace.
When these valves become inoperative, it is typically one or both of
the coils that fail. In order to determine which coil is at fault, you
need to conduct a continuity test on both leads of each coil. The
resistance on a good coil will be 30-50 ohms. If the resistance is not
in this range the coil is defective and must be replaced.
The coils on this valve are wired in parallel. Therefore, when
replacing the wires on these coils, it is important that they be
attached per the diagram. The red 12VDC supply wires must be
attached to terminals 1 and 4 and the ground wires must be
attached to terminal 2 and 3. If the coils are mistakenly wired in
series and there is a marginal supply voltage, there will be a voltage
drop from coil to coil and the valve will not open.
Valve
coil
Volt-ohm meter
30 to 50 OHMS
enclosed
NO
DEFLECTOR
OPEN
DOUBLE MESH,
NO DEFLECTOR
LARGER PORT HOLES
79-II, 85-IV
1522, 2334 89-III
2540
8531 & 35-III 85-III -16, 20, 25
OPENOPEN
26
20 lb. Bottle (*30 lb. bottle multiply X 1.40)
% Full +20° 0° -5° -10° -15°
60% 36,000 18,000 12,750 8,500 4,250
50% 32,400 16,200 12,150 8,100 4,050
40% 28,800 14,400 11,400 7,600 3,800
30% 25,200 12,600 10,450 7,300 3,150
20% 21,600 10,800 8,100 5,400 2,700
10% 16,200 8,100 6,075 4,050 2,025
65 lb. Under Mtd. LP Gas Tank BTU available at
% Full +20° 0° -5° -10° -15°
60% 95,600 47,800 36,000 23,900 12,100
50% 86,000 43,000 32,250 21,500 11,750
40% 77,000 38,500 29,250 19,250 9,625
30% 68,000 34,000 25,500 17,000 8,500
20% 58,000 29,000 21,750 14,500 7,250
10% 43,200 21,600 16,200 10,800 5,400
#1 - GAS PRESSURE
The gas pressure should be set at a minimum of 11˝ W.C.
with a minimum of 50% and ideally 100% of the gas fired
appliances operating. You should test this pressure with a U-
tube Manometer only. If you choose to use a dial-type
manometer, calibrate it often with a U-tube manometer.
#2 - VOLTAGE
Voltage to the furnace should be between 10.5 and 13.5 VDC
during operation with the interior lights ON and OFF. This
check should be made with the battery, converter or
generator when applicable. Use a digital or analog multi-
meter when taking voltage readings. Do not use a test light. It
does not provide enough useful information for proper
diagnosis.
#3 - DUCTING
Always make sure that the furnace has at least the minimum
number of ducts (not including closeable outlets) called out
in the installation instructions. Check for proper duct
connections at the furnace and heat registers, collapsed
ducts and holes in the ducting. The duct runs must be as
straight and tight as possible. The heat ducts must also be
clean and clear of obstructions.
#4 - RETURN AIR
The return air passage should meet the minimum square
inches as specified for the particular model of furnace in the
installation instructions. This air passage should also be
clean and clear of obstructions. Do not put air filters in this
passage way. Also make sure that combustibles are not
stored in the furnace compartment.
Remember that you are working on a heating system and not just a furnace. A majority of furnace problems lie outside of the
product itself. Therefore, when trouble-shooting a furnace problem, always check the following items before testing or
replacing components.
A furnace is a consumer’s friend when the outside
temperature gets colder. Unfortunately though, cold is an
enemy of LP gas. The BTU capacity of LP per volume
decreases as the outside temperature gets colder. Therefore,
based on how full the LP tanks are, the ambient temperature
outside and how many BTU’s the furnace is, there may not be
enough gas to sustain ignition on the furnace.
Using the charts below, let’s say that a 40,000 BTU furnace
won’t fire up, and we also know that the 65 lb. LP bottle on
the RV is 40% full and it is 0 degrees F. outside. One’s first
thought might be that the burner or valve is bad. However, if
we use the chart, the vaporization capacity of the tank in
these conditions is only 38,500 BTU’s. The furnace is not
going to perform very well because there is insufficient BTU
capacity in the tank.
If you were to put an insulated fire resistant blanket over the
tanks and a 75 watt light bulb under that, you would probably
raise the temperature of the bottles 10-20 degrees and
almost double the BTU capacity of the tank. This in turn
would allow the furnace to operate properly. So keep in mind
that a furnace problem is not always a component problem.
The 4 Always
#1 - Gas Pressure
27
#2 - Voltage
See 4 Always previous page.
#3 - Minimum Ducting Requirements
The various BTU sizes of 85, 89 and 2-stage series furnaces require a minimum number of square inches of heat ducting.
The most common size of soft ducting is 4˝ diameter. Therefore, since a 4˝ duct is equal to 12 square inches, we can call
out the minimum number of ducts needed for the models of furnaces noted below.
Furnace Model Minimum Minimum
Ducting Ducts
8516, 8520 24 sq. in. 2
8525. 8531 36 sq. in. 3
8535, 8935, 8940, 1522, 2334, 2540 48 sq. in. 4
CAUTION - Ducting Installation
4˝ Flexible Hose
• each 90° bend adds the equivalent of 10 feet of ducting
• ducting should be securely attached to furnace
• each run should be as straight and short as possible
2˝ Flexible Hose
• 2 - 2˝ duct runs do not equal one 4˝ duct. A 2˝ duct is only 3 sq/inches
• 2˝ duct adapters are available
• 2˝ ducts are ideally suited for bathroom and holding tank compartments
Closeable Outlets
• a closeable outlet does not contribute to the minimum of total outlets recommended for a furnace.
Bottom Discharge
• furnace must be completely sealed to floor and plenum with a bottom discharge gasket, with no air gaps.
• if furnace is installed in middle of run, the main duct run must be a minimum of 24 sq/inches.
• if furnace is installed at the end of the run, the main duct must be 48 sq/inches.
#4 - Return Air
This return air requirement can be met in a couple of ways.
• The return air grille mounted on an inside wall of the trailer, exposed to
the cabinet area of the furnace is the most common mounting used on
the 85, 89 and 2-Stage Series furnaces.
• Another option is to provide openings at various locations in the furnace
cabinet area capable of drawing air from inside the trailer (ie. rowtered
holes at bases of sofas or walls, etc.).
The total square inches of openings must meet minimum requirements.
Do not place any types of air filters in front of or behind the return air door.
Blocking this area will substantially decrease the return air causing - less
air delivery to the heat registers - short cycle of the furnace - limiting of
the furnace.
We recommend electrical air filters that can be placed anywhere in the
open living area of the recreation vehicle. They can be purchased in most
hardware stores.
Outside of RV
Duct #1
Duct #2
Duct #3
Duct #5
Duct #6
Duct #7
Bottom discharge
opening 5" x 10"
(127mm x 254mm)
Duct #4
Ducting Locations
85, 89 and 2-Stage
Series Furnaces
65 in
2
80 in
2
85, 1522 and 2334 Series
89 and 2540 Series
33 in
2
79 Series
28
NOTESNOTES
THIS PAGE INTENTIONALLY LEFT BLANK
29
Guides are only intended for use on Atwood®products by service technicians who have successfully completed
Atwood®training. This guide should be used in conjunction with the appropriate Instruction Manual provided with the
product and any applicable Industry Standards. This is not intended to be a complete list. Please direct questions
concerning service of Atwood®products to 800-825-4328 option 5 before proceeding.
CAUSE SOLUTION
BLOWER DOES NOT RUN
Temperature selector out of place--------------------Re-set to desired position
Thermostat wires broken or disconnected----------Not covered under warranty.
Heat anticipator burned out --------------------------Dead short (not covered under warranty). Repair short and then replace
thermostat.
Faulty relay drawing more than 1 amp. Replace relay and thermostat. Covered
under warranty.
No continuity through thermostat with
contacts closed and switch on. ----------------------Replace thermostat.
Continuity through thermostat with
contacts closed and switch on. ----------------------• Check and reestablish power to thermostat
• Reset tripped circuit breaker.
• Correct poor ground.
• Correct any loose wires.
• Replace defective relay.
• Replace defective motor.
FURNACE DOES NOT CYCLE PROPERLY
Furnace cycles too quickly ----------------------------Move anticipator to a higher amp setting to lengthen cycle. NOT covered
under warranty.
Thermostat located too close to a heat duct. Move thermostat or duct outlet.
NOT covered under warranty.
High temperature variance ----------------------------Move anticipator to a lower amp setting to shorten cycle. NOT covered under
warranty.
Note: When the anticipator is set properly and the heating system has operated for a few hours, the furnace should
cycle 5-6 time per hour.
hydro flame
Thermostat
TROUBLE SHOOTING GUIDE
Effective: 8/10/98
30
30
*indicates NOT covered under warranty.
Guides are only intended for use on Atwood®products by service technicians who have successfully completed
Atwood®training. This guide should be used in conjunction with the appropriate Instruction Manual provided with the
product and any applicable Industry Standards. This is not intended to be a complete list. Please direct questions
concerning service of Atwood®products to 800-825-4328 option 5 before proceeding.
CAUSE SOLUTION
BURNER FAILS TO IGNITE AND - BLOWER FAILS TO RUN
No electrical power to the furnace ----------Reconnect or replace power source.*
Thermostat defective ----------------------------Replace thermostat
Thermostat wires broken or shorted --------Replace wire or wires*
Current overload protector device ----------Reset circuit breaker. Check amp draw from motor
Defective or tripped (circuit breaker). ------According to furnace’s specifications.
Blower relay defective --------------------------Replace relay
Wire off motor ------------------------------------Reconnect wire
Wire off relay--------------------------------------Reconnect wire
Improper ground --------------------------------Clean and secure grounds*
Blower motor defective ------------------------Replace motor
BLOWER RUNS - BUT FAILS TO IGNITE
Low Voltage/High Voltage----------------------Correct Power Supply*
Gas pressure incorrect--------------------------Set pressure to a minimum of 11˝ W.C. with all appliances running.
(Replace regulator if not obtainable).*
Furnace grounding wires not secure --------Clean and secure grounds established*
Air intake restricted------------------------------Clean air intake.*
12 volt polarity reversed------------------------Correct polarity*
Motor running slow------------------------------Check voltage first. If 12 VDC while running, replace motor.
Exhaust blocked ----------------------------------Clean exhaust.*
Combustion air wheel loose ------------------Reposition and tighten.
Sail switch defective or wire off --------------Reconnect wire or replace.
Limit switch defective or wire off ------------Reconnect wire or replace.
Edge connector on circuit board dirty ------Clean with pencil eraser*
Circuit Board defective--------------------------Clean plug contacts. If still defective, replace. (check on board tester
when possible).
Gas valve defective ------------------------------Replace valve or valve coil, depending on problem encountered.
Main burner orifice blocked--------------------Clean main burner orifice or replace.
High tension lead wire defective--------------Replace wire
Electrode out of adjustment ------------------Adjust electrode (take care not to damage porcelain).
Electrode defective ------------------------------Replace
Obstructed burner head ------------------------Clean burner head*
BURNER IGNITES BUT IGNITION SYSTEM “LOCKS OUT” AND TURNS BURNER OFF
Low gas pressure --------------------------------Set pressure to a minimum of 11˝ W.C. with all appliances running.
Replace regulator if not obtainable.*
Exhaust blocked ----------------------------------Clean exhaust.*
Combustion air wheel loose ------------------Reposition wheel and tighten
Electrodes out of adjustment------------------Adjust electrode according to furnace specifications.
Electrode defective ------------------------------Replace electrode.
Circuit Board defective--------------------------Clean plug contacts. If still defective, replace. (Check on board tester
when possible).
Flame sensor wire between electrode ------Replace wire
and circuit board defective
Air leakage at gaskets --------------------------Replace gasket
Defective heat exchanger ----------------------Replace heat exchanger
FURNACE -Electronic Ignition Model
TROUBLE SHOOTING GUIDE
Effective: 8/10/98
continued backside
31
FURNACE - ELECTRONIC IGNITION Model (continued) Effective: 8/10/98
CAUSE SOLUTION
SOOTING (caused by lazy yellow flame)
Low gas pressure ----------------------------------------------*Set pressure to a minimum of 11˝ W.C. with all appliances
running. Replace regulator if not obtainable.
Low voltage------------------------------------------------------Correct power supply*
Air leakage at gaskets ----------------------------------------Replace gaskets
Combustion wheel installed backwards or loose ------Reposition wheel and tighten.
Blockage in heating chamber or burner head ----------Clean or replace
Faulty motor ----------------------------------------------------Replace motor
Wrong vent kit or draft cap ----------------------------------Replace with correct vent kit or draft cap
FAN RUNS CONTINUOUSLY WITH THERMOSTAT “OFF”
Defective thermostat ------------------------------------------Replace thermostat
Shorted thermostat leads ------------------------------------*Replace wire or wires
Defective relay --------------------------------------------------Replace relay
LIMITING = BURNER CYCLING ON AND OFF - BLOWER RUNS CONSTANTLY WITH THERMOSTAT ON
Restricted or insufficient discharge ducting ------------a. Ducting must meet furnace’s minimum requirements.*
b. No excess ducting or unnecessary bends.*
c. All closeable registers must be fully open and unrestricted.*
Furnace over fired ----------------------------------------------Set gas pressure to a minimum of 11˝ W.C. with all appliances
running replace regulator, if not obtainable. Also, check main
burner orifice, it must comply with furnace’s specifications.*
Restricted return air supply----------------------------------Make sure return air meets furnace minimum requirements.*
Defective limit switch------------------------------------------Replace limit switch
BLOWER SHUTS OFF AT SAME TIME BURNER SHUTS OFF
Wired wrong ----------------------------------------------------*Correct wiring
Faulty relay ------------------------------------------------------Replace relay.
BLOWER VIBRATES OR IS NOISY
Motor mount loose --------------------------------------------Tighten motor mounting bracket
a. Ducting must meet furnace’s minimum requirements*
b. No excess ducting or unnecessary bends.*
c. All closeable registers must be fully open and unrestricted.
Damaged blower wheel --------------------------------------Replace blower wheel.
Motor shaft bent------------------------------------------------Replace motor
INSUFFICIENT HEAT
Furnace under fired --------------------------------------------1. Set gas pressure to 11˝ W.C. with all appliances running,
replace regulator if not obtainable. Also, check main burner
orifice, it must comply with furnace’s specifications.
2. Check ducting and return air according to furnaces
specifications.*
Furnace improperly sized for coach/or conditions ----Replace furnace with proper size.
32
32
*indicates NOT covered under warranty.
Guides are only intended for use on Atwood®products by service technicians who have successfully completed
Atwood®training. This guide should be used in conjunction with the appropriate Instruction Manual provided with the
product and any applicable Industry Standards. This is not intended to be a complete list. Please direct questions
concerning service of Atwood®products to 800-825-4328 option 5 before proceeding.
CAUSE SOLUTION
BURNER FAILS TO IGNITE AND - BLOWER FAILS TO RUN
No electrical power to the furnace --------------Reconnect or replace power source.*
Current overload protector device --------------Reset circuit breaker. Check amp draw from motor defective or
tripped (circuit breaker).according to furnace’s specifications.
Thermostat defective--------------------------------Replace thermostat.
Thermostat wires broken --------------------------Replace wire or wires.
Thermostat located in high area------------------Relocate thermostat.
Blower motor defective ----------------------------Replace motor.
Blower relay defective ------------------------------Replace relay.
Wire off motor----------------------------------------Reconnect wire.*
Wire off relay------------------------------------------Reconnect wire.*
Improper ground ------------------------------------Clean and secure grounds.*
BLOWER RUNS - BUT FAILS TO IGNITE
Low Voltage/High Voltage--------------------------Correct power supply.*
12 volt polarity reversed----------------------------Correct polarity.*
Furnace grounding wires not secure------------Clean and secure grounds established*
Gas valve defective ----------------------------------Replace valve or valve coil, depending on problem encountered.
Gas pressure incorrect------------------------------*Set pressure to a minimum of 11˝ W.C. with all appliances running.
(Replace regulator if not obtainable).
Limit switch defective or wire off ----------------Reconnect wire or replace.
Sail switch defective or wire off------------------Reconnect wire or replace.
Burner orifice blocked ------------------------------Clean main burner orifice or replace.
Combustion air wheel loose ----------------------Reposition and tighten.
Burner head adjustment----------------------------Reposition and tighten. Adjust burner according to furnace
specifications.
Exhaust blocked--------------------------------------Clean exhaust.*
Air intake restricted----------------------------------Clean air intake.*
Broken or loose wire--------------------------------Replace or tighten*
Motor running slow --------------------------------Check voltage first. If 12 VDC while running, replace motor.*
Pilot orifice plugged --------------------------------Clean or replace orifice
Thermocouple defective----------------------------Replace thermocouple
Pilot assembly defective----------------------------Replace pilot assembly
BURNER CYCLING ON AND OFF - BLOWER RUNS CONTINUOUSLY WITH THERMOSTAT “ON”
Restricted return air supply ----------------------Make sure return air meets furnace’s minimum requirements.
Restricted discharge duct system----------------a. Make sure ducting meets furnace’s minimum requirements.*
b. Make sure there is no excess ducting or unnecessary bends.*
c. Make sure any closeable registers are fully open and unrestricted.
Defective limit switch ------------------------------Replace limit switch.*
Furnace over fired------------------------------------Set gas pressure to a minimum of 11˝ WC with all appliances
running. Replace regulator if not obtainable. Also, check main burner
orifice, it must comply with furnace’s specifications.
FURNACE - Pilot Model
TROUBLE SHOOTING GUIDE
Effective: 8/10/98
continued backside
33
FURNACE - Pilot Model (continued) Effective: 8/10/98
CAUSE SOLUTION
BLOWER SHUTS OFF AT SAME TIME BURNER SHUTS OFF
Faulty relay --------------------------------------------------------Replace relay
Thermostat wired wrong --------------------------------------Correct wiring*
BURNER FAILS TO IGNITE AND - BLOWER FAILS TO RUN
No electrical power to the furnace --------------------------Reconnect or replace power source.*
BLOWER VIBRATES OR IS NOISY
Damaged blower wheel ----------------------------------------Replace blower wheel.
Motor shaft bent--------------------------------------------------Replace motor
Loose motor ------------------------------------------------------Tighten motor mounting bracket.
Restricted discharge duct system----------------------------a. Make sure ducting meets furnace’s minimum
requirements.* b. Make sure there is no excess ducting or unnecessary
bends.*
c. Make sure any closable registers are fully open and
unrestricted.*
PILOT FAILS TO IGNITE OR STAY LIT
Plugged pilot orifice --------------------------------------------Clean or replace pilot orifice.
Electrode out of adjustment ----------------------------------Adjust electrode to furnace’s specifications.
Pilot tube defective ----------------------------------------------Replace tube.
Piezo sparker defective ----------------------------------------Replace sparker
Defective thermocouple ----------------------------------------Replace thermocouple.
Defective valve----------------------------------------------------Replace valve.
Vent kit not sealed ----------------------------------------------Seal vent where it meets with the furnace.*
MICA window missing------------------------------------------Replace MICA
Combustion air hose plugged or collapsed----------------Replace combustion hose
Water in propane ------------------------------------------------Add alcohol to the propane bottles.*
Burner plate gasket or ----------------------------------------Replace gaskets
pilot gasket not sealed
LAZY FLAME (yellow)
High gas pressure------------------------------------------------*Set pressure to a minimum of 11˝ W.C. with all appliances
running. Replace regulator if not obtainable.
Burner out of adjustment --------------------------------------Adjust burner according to furnace specification.
Combustion wheel installed backwards or loose --------Reposition wheel and tighten.
Air leakage at gaskets ------------------------------------------Replace gaskets
Low voltage--------------------------------------------------------Correct power supply*
FAN RUNS CONTINUOUSLY WITH THERMOSTAT “OFF”
Shorted thermostat leads --------------------------------------Replace wire or wires.
Defective relay ----------------------------------------------------Replace relay
Defective thermostat --------------------------------------------Replace thermostat
INSUFFICIENT HEAT
Furnace under fired----------------------------------------------1. Set gas pressure to 11˝ W.C. with all appliances running,
replace regulator if not obtainable. Also, check main
burner orifice, it must comply with furnace’s
specifications.*
2. Check ducting and return air according to furnaces
specifications.
Furnace limiting --------------------------------------------------Check ducting and return air. It must comply with furnace’s
specifications.*
*indicates NOT covered under warranty.
34
Terminology Definition
AC Motor A Motor operating on 120 volts A.C.
Adjustable Register A heat outlet capable of being opened
and closed.
Air Speed Indicators (Velometer) A tool used to measure
the velocity of air movement from a
duct outlet.
Ambient Air Temp. Current room air temperature.
Amp Draw The amount of current required to run
a given component.
Burn Off The time it takes for the furnace
Combustion Chamber to burn off all
the oils and lubes used in production.
Burner The component in the furnace where
combustion occurs creating the main
source of heat within the Combustion
Chamber.
Burner Flame Lift Off When the flame lifts off the Burner.
Candling A small flame at the Main Burner
Orifice when the Valve is in a closed
position.
Circuit Breaker A normally closed switch that
automatically interrupts an electrical
circuit under abnormal AMP loads.
Circulating Air Air drawn into the furnace by the Main
Air Wheel then heated and forced out
the heat outlets.
Combustion Air Air supplied to the Burner specifically
for combustion.
Combustion Chamber The component where combustion
occurs and transfers heat to
circulating air.
Converter Component that is used to change
120 VAC to 12 VDC. Available in linear,
pharo-resonant and switching styles.
Cycling The normal on and off operation of the
furnace controlled by the thermostat.
DC Motor Motor operating on 12 VDC.
Circuit Board A Circuit Board in the furnace
controlling the ignition sequence and
proves a flame has been established.
Electrode Both a conductor establishing an
electrical spark at the Burner to ignite
the air to gas mixture, and a sensor to
signal the circuit board the flame is
established.
Terminology Definition
Fan Switch A normally open switch that closes at
a set temperature allowing power flow
to the motor, and allows the motor to
run after the burner shuts down to
cool down the combustion chamber.
Field The Wiring Harness that connects the
Electrical Hook Up furnace to the coach wiring.
Flair Fitting Brass fitting used to connect the
furnace to the gas supply.
Flash Back A condition when the flame burns on
the inside of the burner.
Flex Ducting A round, collapsible, wire reinforced
product used to deliver the heated air
from the furnace to the living area.
Forced Combustion A type of combustion when a second
air wheel is used to force air into the
burner to increase the air to gas
mixture.
Gas Pressure The amount of gas being supplied to
the furnace, measured in column
inches.
Gas Valve A mechanical device by which the flow
of gas is started or stopped by an
electrical signal.
Gravity Combustion A type of combustion using no other
source but gravity to supply
combustion air for the proper air to
gas mixture at the burner.
Hard Ducting (See Floor Ducting)
Heat Anticipator Component of a Thermostat that can
be adjusted to increase or decrease
the length of the heating cycle.
Heating Element (See Combustion Chamber)
High Tension The wire carrying the high tension
Lead Wire spark from Circuit Board to Electrode.
Incline Manometer Tool used to measure Static Pressure
of the furnace plenum.
Junction Box A box inside or outside of the furnace
where electrical connections are made.
Limit Switch A normally closed switch that opens at
a set temperature which does not
allow the furnace to over heat.
Limiting A condition caused by over-heating
the Limit Switch The burner turns on
and off during a heating cycle.
FURNACE TERMINOLOGY
35
Terminology Definition
Loud Ignition A condition where the air to gas
mixture is off and the burner lights
with a loud noise.
Main Burner Orifice The Orifice regulating the amount of
gas delivered to the Burner.
Manifold The tube delivering gas from the Gas
Valve to the Main Burner Orifice.
Manual Reset Switch A Limit Switch manually reset after
reaching it’s set temperature.
MicroAmps: Amps sent back to the Circuit Board to
establish a flame is present.
Millivolts Voltage created by a Thermocouple or
Thermopile.
Multi-Try Circuit Board providing 2 or 3 trials
Circuit Board for ignition.
OEM A manufacture of recreational vehicle,
“Original Equipment Manufacture”.
Pig Tail (see Field Electrical Hook Up)
Pilot Light Assembly An assembly used to light the burner.
Plenum The metal box enclosing the
Combustion Chamber directing the
heated air to the duct outlets.
Power Supply A source of electrical power, usually a
converter, inverter or battery.
Primary Air A portion of the combustion air mixing
directly in the Burner at the Main
Burner Orifice.
Resonating A whining noise created by a Burner
with an improper air to gas mixture.
Return Air Air pulled into the furnace, heated,
force through duct outlets back to the
living area.
Safety Lockout Circuit Board not sensing a flame,
cutting power to the Gas Valve.
Sail Switch Air prover switch that will engage
when the Blower Motor reaches 75%
of the rated RPM.
Secondary Air Combustion Air that helps complete
the combustion after the Burner is on.
Sensor Wire Wire carrying an electrical signal from
the Electrode back to the Circuit Board
on a remote sense system.
Slope Gauge (see Incline Manometer)
Terminology Definition
Sooting A black powder that builds up around
the Burner in the Combustion
Chamber normally caused by an
improper air to gas mixture.
Start Capacitor A device giving an electrical boost to
start an A/C motor.
Static Pressure Amount of pressure inside the Furnace
Plenum or Duct caused by the ability
to dispel air out the duct outlets.
Thermocouple Safety device used to generate an
electrical signal sent to the Gas Valve
to hold the Pilot Flame on.
Thermopile Safety device much like a
Thermocouple. It gives a much higher
electrical output, also used to open the
Main Valve with a Thermostat.
Thermostat Device used with the Furnace to
regulate the room air temperature.
Time Delay Relay A normally open Relay. When
activated closes, sending power to the
Blower Motor. When deactivated
allows Blower to run for a period of
time to cool the Combustion Chamber.
Transformer Device reducing 120 VAC to 24 VAC.
U-Tube Tool measuring gas pressure in inches
of water.
VOM Meter reading voltages and OHMs
resistance.
Valve Coil Electromagnetic Coil on the Gas Valve
holding and releasing a plunger to
start and stop the flow of gas.
36
Return Goods Policy
Effective August 7, 1995, all Atwood defective returns will no longer
be repaired at the warehouses and returned to customers. Defective
returns will be shipped back to the respective manufacturing facility
for problem cause analysis within 30 days of sales. Full credit will be
issued if the cause analysis determines Atwood is responsible. If the
cause analysis determines the customer is responsible, partial or no
credit will be issued.
Warranty Returns - the warranty policy, must return policy and
approved labor rates provide the framework for warranty returns by
product line.
Non-Defective Returns - A restocking fee of 20% will be charged
for handling of overstock returns or standard stock items ordered
incorrectly by the customer providing the product is received in
resalable condition. Product that has been specifically designed at
a customers request is non-returnable. Obsolete or out dated
product will not be accepted for credit.
Shipping Damage - Once the product has been accepted at its final
destination it is the customers responsibility to file a damage claim
with the carrier.
Follow Warranty Procedures for Atwood returns.
Return Parts
When returning parts, there are three divisions responsible for
specific product and their claims. Prior to returning parts, a Return
Goods Number (RGN) must be obtained by calling the Atwood
Mobile Product Service Department at 800-825-4328.
Shipping - Reasonable shipping charges are reimbursed on
defective and warranty parts if the analysis determines Atwood is
responsible for the disposition. All products not shipped via Atwood
trucks should be shipped prepaid via UPS ground unless negotiated
at the time the RGN is given. No collect shipments will be accepted.
Packaging - The RGN must be identified on each container & all
packing information. Product returned must be properly packaged
to prevent shipping damage. Full credit will not be issued on
product sent back on an open skid or improperly packaged.
Additional product boxes are available upon request.
Submit claims to the correct division. Failure to do so makes claim
processing a more difficult and lengthy process delaying payment of your
claims. Together we can maintain a speedy and efficient warranty program.
WATER HEATERS//HARDWARE (jacks, couplers, 5th wheel & braking systems)
Atwood Mobile Products
4750 Hiawatha Drive
Rockford, IL 60013
Must Return Parts List
Under Atwood’s Warranty Administration Program we require,
with the return of warranty claims, the specific parts noted below.
Failure to accompany your claims with these parts will result in
the non-shipment of a replacement part, or the non-processing
of the appropriate credit until such time as the part is received by
Atwood.
Before returning the part, a RGN (Return Goods Number) must be
obtained. This number can be acquired for all products except
seating, by calling the Atwood Mobile Products Service
Department at 1-800-825-4328. To obtain RGN’s for seating
components, please call 1-219-522-7891. Without this RGN
appearing on the outside of the shipping carton, the shipment
will be refused at our receiving department.
FURNACE
All parts
HARDWARE
Couplers
Jacks
Actuators
Master cylinders
Shock absorbers
Foundation brakes
Power jacks
Power jack motors
All 5th Wheel items
RANGE & OVENS
Regulators
Oven thermostats
Safety pilot valves
Burner valves
Manifolds
Top pilot valves
12v ignition module
Burners w/ignition
electrode
Complete ranges (BY
APPROVAL ONLY)
SEATING COMPONENTS
All parts
WATER HEATER
Complete water heaters
Inner tanks
Gas thermostat valves
Circuit boards
Gas solenoid valves
Electric thermostats
Heating elements
Pilot assemblies
Spark probe assemblies
E.C.O. & T-stat kits
Thermal cut-offs
Pressure-Temperature
Relief
Valves
FOR EFFICIENT PROCESSING OF CLAIM
1. Call for a RGN number.
2. Fill Warranty Service Report form out completely.
3. Using tape or a tag mark the returning part with the
RGN #.
4. Package part including the Warranty Service Report in
the box.
5. On the outside of the package clearly mark the RGN
number.
6. Return part to the correct Division of Atwood Mobile
Products.
FURNACE/LP DETECTORS
Atwood Mobile Products
Salt Lake City Operations
1874 South Pioneer Road
Salt Lake City, UT 84104
CO DETECTOR
KIDDE Safety (1-800-880-6788)
1394 South Third Street
Mebane, NC 27302
RANGE/COOK TOPS/DROP-INS/SOL-A-VENTS
Atwood Mobile Products
Wedgewood Operations
6320 Kelly Willis Road
Greenbrier, TN 37073
37
37
ATWOOD MOBILE PRODUCTS
hydro flame TM
FURNACE LIMITED WARRANTY
Atwood Mobile Products warrants to the original owner and subject
to the below mentioned conditions, that this product will be free of
defects in material or workmanship for a period of two years from
the original date of purchase. Atwood’s liability hereunder is limited
to the replacement of the product, repair of the product, or
replacement of the product with a reconditioned product at the
discretion of Atwood Mobile Products. This warranty is void if the
product has been damaged by accident, unreasonable use, neglect,
tampering or other causes not arising from defects in material
workmanship. This warranty extends to the original owner of the
product only and is subject to the following conditions:
1. For two years from the date of purchase, Atwood will repair or
replace any part defective in material or workmanship. This
warranty includes reasonable labor charges required to remove and
replace the part. Service calls to customer’s location are not
considered part of these charges and are, therefore, the
responsibility of the owner.
2. This warranty does not cover the following items classified as
normal maintenance:
ADJUSTING - gas pressure, voltage, loose wire connections, and/or
thermostat heat anticipator
CLEANING - air wheels, burner and/or burner orifice
CLEANING OR ADJUSTING - heat chamber, heat ducting, return air
opening, and/or exhaust tubes
3. In the event of a warranty claim, the owner must contact, in
advance, either an authorized Atwood Service Center or the
Atwood Service Department. Warranty claim service must be
performed at an authorized Atwood Service Center (a list will be
provided at no charge) or as approved by the Consumer Service
Department, Atwood Mobile Products, 4750 Hiawatha Drive,
Rockford, IL 61103-1298 USA.
Phone: 815-877-5700
4. RETURN PARTS MUST BE SHIPPED TO ATWOOD “PREPAID”.
Credit for shipping costs will be included with the warranty claim.
The defective parts become the property of Atwood Mobile
Products and must be returned to the Quality Assurance Dept.,
Salt Lake City Operations, 1874 South Pioneer Road, Salt Lake
City, Utah 84104 USA.
5. This warranty applies only if the unit is installed according to the
installation instructions provided and complies with local and state
codes.
6. The warranty period on replacement parts is the unused portion of
the original warranty period.
7. Damage or failure resulting from misuse (including failure to seek
proper repair service), misapplication, alterations, water damage,
freezing or not using genuine Atwood parts are the owner’s
responsibility.
8. Atwood does not assume responsibility for any loss of use of
vehicle, loss of time, inconvenience, expense for gasoline,
telephone, travel, lodging, loss or damage to personal property or
revenues. Some states do not allow the exclusion or limitation of
incidental or consequential damages, so the above limitations or
exclusions may not apply to you.
9 Any implied warranties are limited to (2) two years. Some states do
not allow limitations on how long an implied warranty lasts, so the
above limitation may not apply to you. This warranty gives you
specific legal rights and you may also have other rights which vary
from state to state.
10. Replacement parts purchased outside of the original furnace
warranty carry a 90 day warranty. This includes the part at no
charge and reasonable labor charges to replace it.
This hydro flame furnace is designed for use in recreation vehicles for
the purpose of heating air as stated in the “data plate” attached to
furnace. Any other use, unless authorized in writing by the Atwood
Engineering Department, voids this warranty. 9/03
ATWOOD MOBILE PRODUCTS
hydro flame TM
FURNACE EXTENDED SERVICE CONTRACT
TERMS AND PROVISIONS:
1. Written approval by Atwood must be obtained prior to
having any repairs made or parts replaced under these
Warranties at other than an Atwood Authorized Service
Center. A list can be obtained by calling 1-815-877-5700.
Any such unauthorized charges will not be paid by Atwood.
2. Air freight or postage charges shall be borne by party
claiming under Warranties. The Original Purchaser shall have
the full responsibility of making the furnace or RV available
for repair or replacement at Atwood Mobile Products, Salt
Lake Operations or at an Atwood Authorized Service Center.
Service calls are not covered under the normal two year
warranty.
3. Atwood’s Authorized Service Centers are neither agents nor
employees of Atwood and at all times will be acting as
independent contractors with the Original Purchaser. Atwood
will reimburse service centers for warranty service rendered
on a direct basis only.
4. Repairs, replacement parts and or furnace replacement
authorized by Atwood shall be subject to the remainder of
the warranty, if any of the aforesaid two year period.
Exclusions (specifically excluded from the warranties)
1. Incidental or consequential damages.
2. Damaged caused by shipment.
3. Damage resulting from improper installation, misuse,
neglect, accident or use in violation of instructions furnished
by Atwood Mobile Products.
4. Equipment and parts which have been altered in any way
whatsoever without written authorization from Atwood
Mobile Products.
5. All repairs and replacement parts not authorized by Atwood
Mobile Products.
6. Preventative maintenance.
Limitations
1. The maximum liability of Atwood Mobile Products in
connection with this limited warranty shall not in any event
exceed the original price paid for the furnace claimed to be
defective or unsuitable.
2. Components manufactured by any supplier other than
Atwood Mobile Products shall bear only that warranty made
by the manufacturer or supplier of that product. 3/97
3838
Flat Rate
Schedule
hydro flameTM
Furnaces
AND Detectors
TIME ALLOWANCE SCHEDULE in hours
85 DC89 AC89 8012 79
II, III & IV I & II & III I & II & III I & II I & II
1522 & 2334 2540
Air Box Extension.....................................................................................................................................................................................................................70.......................................70............
Air Wheel (Circulating).........................................75.........................................75 .......................................75....................................1.00..................................1.00............
Air Wheel (Combustion)..............................1.00 ..................................1.00..................................1.00....................................1.00..................................1.00............
Blower Housing.................................................................50.........................................50 .......................................50 ..................................................................................................................
Burner...................................................................................................60.........................................60 .......................................60.........................................80.......................................80............
Burner Box.................................................................................70.........................................70 .......................................70 ..................................................................................................................
Burner Plate.........................................................................................................................................................................................................................................80.......................................80............
Burner Plate Gasket.............................................................................................................................................................................................................75.......................................75............
Casing............................................................................................1.00 ..................................1.00..................................1.00....................................1.50..................................1.50............
Circuit Breaker.....................................................................40.........................................40 .......................................40.........................................80.......................................80............
Combustion Chamber....................................1.50 ..................................1.50..................................1.50....................................1.50..................................1.50............
Door.........................................................................................................70.........................................70 .......................................70.........................................30.......................................30............
Draft Cap.......................................................................................30.........................................30 .......................................30 ..................................................................................................................
Circuit Board...........................................................................70.........................................70 .......................................70.........................................70.......................................70............
Circuit Board Bracket...........................................70.........................................70 .......................................70.........................................70.......................................70............
Electrode.........................................................................................60.........................................60 .......................................60.........................................70.......................................70............
Exhaust Tube.....................................................................................................................................................................................................................................70.......................................70............
Gasket Comb. Chamber............................1.50 ..................................1.50..................................1.50 ..................................................................................................................
Gasket Electrode...........................................................60.........................................60 .......................................60.........................................70.......................................70............
High Tension Lead.......................................................50.........................................50 .......................................50.........................................50.......................................50............
Limit Switch.............................................................................90.........................................90 .......................................90.........................................60.......................................60............
Manifold Inlet.........................................................................75.........................................75 .......................................75 ..................................................................................................................
Manifold Outlet...................................................................75.........................................75 .......................................75....................................1.00..................................1.00............
Motor................................................................................................1.00 ..................................1.00..................................1.15....................................1.15..................................1.15............
Motor Bracket................................................................1.15 ..................................1.15..................................1.15 ..................................................................................................................
Motor Capacitor .....................................................................................................................................................................50 ..................................................................................................................
Motor Mounting Wall........................................1.50 ..................................1.50..................................1.50 ..................................................................................................................
Orifice (Burner)...................................................................60.........................................60 .......................................60.........................................80.......................................80............
Relay.......................................................................................................50.........................................50 .......................................50.........................................60.......................................60............
Sail Switch...................................................................................60.........................................60 .......................................60....................................1.00..................................1.00............
Thermostat.................................................................................50.........................................50 .......................................50.........................................50.......................................50............
Transformer.......................................................................................................................................................................................60 ..................................................................................................................
Valve .......................................................................................................80.........................................80 .......................................80....................................1.00..................................1.00............
Valve Bracket.........................................................................80.........................................80 .......................................80....................................1.00..................................1.00............
Valve Coil.......................................................................................70.........................................70 .......................................70.........................................50.......................................50............
Wiring Harness ............................................................1.00 ..................................1.00..................................1.00....................................1.00..................................1.00............
DETECTORS...........................................................................25
NOTE: If more than one repair is done minus .40 for each additional repair.
NOTE: All flat rates include diagnostic time and when applicable, gas leak test.
July 19, 2001
39
12
23
24
11
15
14
16
17
10
8
23
413
921 20
18
7
6
22
25
19
5
27
30
29 28
30
31
26
1
Item # Description of Parts
1 Front Door
2 Electronic Ignition Board
3 Valve
4 Front Discharge Cover Plate
5 Electrode Cover Plate
6 Electrode
7 Electrode Gasket
8 Heat Exchanger
9 Burner Plate Gasket
10 Sail Switch (79-II)
10 Sail Switch (80-II)
11 Blower Wheel (79-II)
11 Blower Wheel (80-II)
Item # Description of Parts
12 Motor (79-II)
12 Motor (80-II)
13 Combustion Wheel
14 Duct Adapter
15 Duct Cover Plate
16 Air Hose
17 Thermostat -SPECIFY COLOR
18 Limit Switch (L-170)
19 Relay
20 On/Off Circuit Breaker
21 Burner Head
22 Manifold
23 Motor Gasket
Item # Description of Parts
24 Motor Spacer
25 Small Burner Air Baffle - SPECIFY RATE
25 Large Burner Air Baffle - SPECIFY RATE
26 Electronic Ignition Mounting Plate
27 Valve Bracket
28 Vent Kit Specify Length
29 Exhaust Tube Assembly - SPECIFY LENGTH &
MATERIAL
30 Air Box Assembly - SPECIFY LENGTH
31 Orifice - SPECIFY RATE
ENGLISH, FRANCAIS (et Canada) •Installation
Effective 7/01/00
MPD 38137
hydro flame
TM
7900-II / 8000-II
Series Furnace
Technical Installation Manual
40
October 1997
Drawing
# Description of Parts 8516 8520 8525 8531 8535
1 Blower Wheel
4 Asmbly, Plate & Gasket
6 Burner Asmbly
7 Casing Extension Box
8 Circuit Breaker
9 Replacement Coil
10 Combustion Wheel
12 Door Hinges
13 Door Asmbly ◆◆ ◆◆◆
14 Slide Plate
15 Thermostat
17 Valve
18 Wiring Harness
19 Draft Cap Asmbly
20 Electronic Ignition Board (05-30)
22 Duct Adapters
23 Duct Cover Plate
Drawing
# Description of Parts 8516 8520 8525 8531 8535
24 Electrode
25 Electrode Gasket
26 Flex Adapter Plate Asmbly
27 Gas Inlet Plug
28 High Tension Lead
30 Bottom Plenum Plate
32 Limit Switch
35 Motor Gasket
36 Motor Kit
37 Orifice
40 Relay
41 Sail Switch
42 Element Asmbly
43 Exhaust Wall Gasket
45 Recess Pan Asmbly ◆◆ ◆◆◆
◆ Order by Color
28
13
12
46
45
15
20 1
40 46
36
35
10 14
41
18
27
6
24
19
23 22
30
43
32
42
4
26
7
8
17
937
EXCALIBUR
8500-III
SEE PARTS MATRIX PAGES 45-49
Atwood Furnace Installation Parts
41
ENGLISH, FRANCAIS (et Canada) •Installation •Maintenance
Effective 9/1/03
LITERATURE NUMBER MPD 33940
hydro flame
TM
8500-IV Series Furnace
MODELS 8516, 8520, 8525,
8531, 8535
Technical Installation Manual
DRAWING #DESCRIPTION
1 Blower Wheel
3 Motor Clamp
4 Gasket/Plenum Plate Kit- Top & Bottom
6 Burner Assembly
7 Extension Box
8 ON/OFF Switch
9 Replacement Coil
10 Combustion Wheel
11 Door Hinges
12 Door, Standard ORDER BY COLOR
13 Door, Deluxe -SPECIFY COLOR
14 Slide Plate
15 Thermostat - specify color
17 Valve
18 Field Wiring Harness
19 Draft Cap Assembly - Specity model
20 Electronic Ignition Board
22 Duct Adapters
23 Duct Cover Plate
24 Electrode
26 Flex Adapter Plate Assembly Kit
27 Gas Inlet Plug
28 High Tension Lead
30 Top/Bottom/Side Cover
32 Limit Switch
35 Motor Gasket
36 Motor - specify rate
37 Orifice - specify rate
41 Sail Switch
42 Element Assembly - specify model
43 Exhaust Wall Gasket
45 Recess Pan Assembly-SPECIFY COLOR
46 Mounting Bracket
47 Venturi
48 Blower Housing Back
49 Blower Housing
50 Motor/Combustion Wall
51 Circuit Breaker
52 Control Board Mounting Bracket
54 Plenum Plate, Extension Boot
56 Door Fastener Kit
57 Double Housing Field Harness
N/S High Voltage Lead - noise suppresion
28
56
13
11
46
45
15
20
1
46
3
57 36
35
10 14
41
18
27
6
24
23
4
43
32
42
8
47
49
50
48
17
937
12
51
26
7
54
30
52
19
22
42
ENGLISH, FRANCAIS (et Canada) •Installation •Maintenance
Effective 9/1/03
LITERATURE NUMBER MPD 33941
hydro flame
TM
8500-IV-LD Series Furnace
MODELS 8516, 8520,
8525, 8531, 8535
Technical Installation Manual
DRAWING #DESCRIPTION
1 Blower Wheel
3 Motor Clamp
4 Gasket & Plenum Plate Kit
6 Burner Assembly
7 Extension Box
8 ON/OFF Switch / Circuit Breaker - Specify
Model
9 Replacement Coil
10 Combustion Wheel
15 Thermostat - specify color
17 Valve
19 Vent Assembly - Specity Model
20 Electronic Ignition Board
22 Duct Adapters
23 Duct Cover Plate
24 Electrode
26 Flex Adapter Plate Assembly Kit
28 High Tension Lead Cover
30 Top/Bottom/Side Plate
32 Limit Switch
35 Motor Gasket
36 Motor - specify rate
37 Orifice - specify rate
41 Sail Switch
42 Element Assembly - specify model
43 Exhaust Wall Gasket
48 Blower Housing Back
49 Blower Housing
50 Motor/Combustion Wall
52 Control Board Mounting Bracket
54 Plenum Plate Extension Box Assembly
56 Combustion Cover (specify)
57 Extended Manifold
58 Gas Line Gasket
59 Vent Ring
28
15
20
1336
35
10
41
6
24
23
4
43
32
42
58
49
50
48
26
7
54
30
52
22
56
8
19
9
17
59
57
30
37
43
43
ENGLISH, FRANCAIS (et Canada) •Installation
Effective 9/1/03
LITERATURE NUMBER MPD 33938
hydro flame
TM
8900-III Series Furnace
MODELS 8935, 8940
Technical Installation Manual
2
13
35
14
37
32
30
11 10
3
4
31
33
29
7
6
17
36 25
5
1
18
23
34
28
9
16
8
40
38
24
20
39
19
43
44
45
42
41
DRAWING #DESCRIPTION OF PARTS
1 Relay
2 Thermostat - specify color
3 Duct Cover Plate
4 Duct Adapter
5 Orifice — SPECIFY GAS & BTU
6 Combustion Wheel
7 Motor Gasket
8Valve DC
9 Valve Repl Coil DC
10 Gas Inlet Plug
11 Slide Plate
13 Electronic Ignition Board DC Kit
14 Recessed Pan (MUST ORDER BY COLOR)
16 Valve AC
17 Motor DC
18 Sail Switch
19 Draft Cap Assembly DC/AC35
20 Circuit Breaker DC
23 Junction Box Asmbly AC
24 Motor Capacitor AC
25 Element Exhaust Wall Gasket
28 Valve Replacement Coil AC
29 Blower Wheel
30 Electrode
31 Limit Switch
32 Burner Assembly
33 Element Assembly
34 Electronic Ignition Board AC Kit
35 Transformer Assembly AC
36 Motor AC
37 High Voltage Wire
38 Deluxe Door & Bezel Assembly
(MUST ORDER BY COLOR)
39 Draft Cap Assembly AC/DC 40
40 Gasket & Plate Assembly
41 Standard Door & Bezel Assembly
(MUST ORDER BY COLOR)
42 Combustion Cover
43 Door Fastener Kit
44 Recess Pan Bracket
45 Rain Shield
44 44
ENGLISH, FRANCAIS (et Canada) •Installation •Maintenance
Effective 9/1/03
LITERATURE NUMBER MPD 33939
hydro flame
TM
8500-IV
2 Stage Series Furnace
MODELS 1522, 2334
Technical Installation Manual
Patent No US 6,464,000 Other Patents Pending
DRAWING #DESCRIPTION
1 Blower Wheel
3 Motor Clamp
4 Gasket & Plenum Plate Kit
6 Burner Assembly
7 Extension Box
8 ON/OFF Switch
9 Mounting Bracket Valve
10 Combustion Wheel
11 Door Hinges
12 Door, Standard ORDER BY COLOR
13 Door, Deluxe -SPECIFY COLOR
14 Slide Plate
15 Dual Thermostat
17 Valves - (1522 = ORANGE) (2334 = WHITE)
18 Field Wiring Harness
19 Draft Cap Assembly
20 Electronic Ignition Board
22 Duct Adapters
23 Duct Cover Plate
24 Electrode
26 Flex Adapter Plate Assembly Kit
27 Gas Inlet Plug/Seal
28 High Tension Lead
30 Top/Bottom/Side Cover Plate
32 Limit Switch
35 Motor Gasket
36 10 VDC Motor - Specify Model
37 Orifices - (1522 = #54) (2334 = #51)
41 Sail Switch
42 Element Assembly - Specify Model
43 Exhaust Wall Gasket
45 Recess Pan Assembly-SPECIFY COLOR
46 Mounting Bracket
47 Venturi
48 Blower Housing Back
49 Blower Housing
50 Motor/Combustion Wall
51 Circuit Breaker
52 Control Board Mounting Bracket
53 Speed Control Board
54 Adapter Plate
55 Door Fastener Kit
NS High Tension Lead Noise Supression
28
13
11
46
45
1
46
336
35
10 14
41
18
27
6
24
23
4
43
32
42
8
47
49
50
48
17
937
12
51
26
7
54
30
19
22
20
53
52
15 COOL FAN
OFF HEAT M
15
55
45
ENGLISH, FRANCAIS (et Canada) •Installation
Effective 9/1/03
LITERATURE NUMBER MPD 33943
hydro flame
TM
8900-III-LD
2 Stage Series Furnace
MODEL 2540
Technical Installation Manual
Patent No US 6,464,000 Other Patents Pending
DRAWING #DESCRIPTION
1 Blower Wheel
4 Gasket & Plenum Plate Kit
6 Burner Assembly
8 ON/OFF Switch / Circit Breaker
9 Valve Coil Replacement (DC)
10 Combustion Wheel
15 Dual Thermostat
17 Valve
19 Vent Assembly
20 Electronic Ignition Board
22 Duct Adapters
23 Duct Cover Plate
24 Electrode
26 Adapter Plate Assembly
28 High Tension Lead
32 Limit Switch
35 Motor Gasket
36 Motor
37 Orifice - #49
41 Sail Switch
42 Element Assembly
43 Exhaust Wall Gasket
48 Blower Housing Back
49 Blower Housing
50 Motor/Combustion Wall
52 Control Board Mounting Bracket
53 Motor Speed Control Board
54 Adapter Plate
55 Combustion Cover (specify)
56 Extended Manifold
57 Vent Ring
58 Gas Line Gasket
23
22
32
42
1
35
10
36 43
26
20
53
52
15 COOL FAN
OFF HEAT M
50
48
41
24
37
6
12
55
54
57
49
28
8
58
56
17
9
19
46
85-IV 16
85-IV 20
85-IV 25
85-IV 31
85-IV 35
1522 2-stage
2334 2-stage
R-25
Blowers Wheels & Covers
37605 Blower cover - back (outside) ✗✗ ✗ ✗ ✗ ✗✗
37606 Blower cover - front (inside) ✗✗ ✗ ✗ ✗ ✗✗
37607 Blower Venturi Ring ✗✗ ✗ ✗ ✗ ✗✗ ✗
33126 Blower Wheel Kit ✗✗ ✗ ✗ ✗ ✗✗ ✗
Burner
36043 Burner Head ✗✗ ✗ ✗ ✗ ✗✗
35491 Burner Head ✗
Burner Orifices
31257 #56 16,000 BTU ✗
31265 1.25MM 18,000 BTU ✗
31267 #54 22,000 BTU ✗
37580 1.45MM 25,000 BTU ✗✗
31280 #52 31,000 BTU ✗
32285 #51 35,000 BTU ✗✗
34004 Burner Orifice 42 (Nat) ✗
Circuit Board
37966 Controller Module Motor Speed ✗✗
37984 Controller Module Bracket ✗✗
38676 Ignition Board Retrofit Kit (w/fan control) ✗✗ ✗ ✗ ✗
36716 Ignition Board Kit (3 Trial) ✗✗ ✗ ✗ ✗
33686 Ignition Board bracket ✗✗ ✗ ✗ ✗ ✗✗
37965 Ignition Module ✗✗
38224 Ignition Module with Motor Control ✗
Circuit Breakers
33751 7 AMP (with door) ✗✗
33752 10 AMP (with door) ✗✗
34034 15 AMP (with door) ✗✗✗
34011 7 AMP (without door circuit breaker/on/off) ✗✗
34012 10 AMP (without door circuit breaker/on/off) ✗✗
34013 15 AMP (without door circuit breaker/on/off) ✗✗
34015 20 AMP (without door circuit breaker/on/off) ✗
Combustion
37084 Combustion Air Restrictor 1-1/4” ✗✗✗
37085 Combustion Air Restrictor 1-3/4” NLA
33128 Combustion Wheel Kit ✗✗ ✗ ✗ ✗ ✗✗ ✗
Draft Cap
37620 Draft Cap (5/8” Baffle) (before S/N 1260456) ✗✗
37619 Draft Cap (3/8” Baffle) (before S/N 1260456) ✗✗✗
38141 Draft Cap (3/8” Baffle).(after S/N 1260455) ✗✗✗✗✗
38139 Draft Cap (5/8” Baffle).(after S/N 1260455) ✗✗
Electrodes
37057 Electrode ✗✗ ✗ ✗ ✗ ✗✗ ✗
Gaskets
38261 Exhaust Box Gasket No Longer Available
32926 Exhaust Wall Gasket (before S/N 1260456) ✗✗ ✗ ✗ ✗
37956 Exhaust Wall Gasket (after S/N 1260455) ✗✗ ✗ ✗ ✗ ✗✗ ✗
38286 Exhaust Tube Gasket No Longer Available
37713 Motor Gasket No Longer Available
37600 Motor Gasket ✗✗ ✗ ✗ ✗ ✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
47
85-IV 16
85-IV 20
85-IV 25
85-IV 31
85-IV 35
1522 2-stage
2334 2-stage
R-25
Heating Elements
37960 Htg Element Kit* 16, 20 (before S/N 1260456) ✗✗
37961 Htg Element Kit* 25 (before S/N 1260456) ✗
37962 Htg Element Kit* 31, 35 (before S/N 1260456) ✗✗
37958 Htg Element 16, 20, 25 (after S/N 1260455) ✗✗ ✗ ✗
37959 Htg Element 31, 35 (after S/N 1260455) ✗✗ ✗
38282 Htg Element No Longer Available
*Kit includes draft cap & element gasket
Switches
37022 Limit Switch 190˚ ✗✗ ✗ ✗ ✗ ✗✗ ✗
36121 ON/OFF Switch ✗✗ ✗ ✗ ✗ ✗✗
38279 Pressure Switch ✗
36680 Sail Switch Use 37716 ✗✗ ✗ ✗ ✗ ✗✗
Motor
34039 Capacitor ✗
38223 Motor AC ✗
37696 Motor PF 20076Q ✗✗
37697 Motor PF 23199Q ✗✗
37698 Motor PF 26157Q ✗
37964 Motor PF 26170Q ✗
38554 Motor PF 23211Q ✗
37646 Motor Clamp ✗✗ ✗ ✗ ✗ ✗✗
37602 Motor Lock Bracket ✗✗
37603 Motor Lock Bracket ✗✗ ✗
37604 Motor Lock Bracket ✗✗
37801 Motor Mounting Wall Kit ✗✗ ✗ ✗ ✗ ✗✗
Relay31017 Klixon Relay ✗✗ ✗ ✗ ✗
Thermostats
38453 Thermostat (white) Heat only HFH-2000 ✗✗ ✗ ✗ ✗
38452 Thermostat (brown) Heat only HFH-2000 ✗✗ ✗ ✗ ✗
38535 Thermostat, Digital, 2-Stage 2H2C ✗✗
38555 Thermostat, Digital, Single Stage 1H2C ✗✗ ✗ ✗ ✗
38291 Thermostat ✗
Valves
37383 Valve, W/R 25M16V-711 ✗✗ ✗ ✗ ✗
37384 Valve W/R 25M18-711 ✗
37973 2-Stage Valve W/R 25M05V-701 ✗
38564 2-Stage Valve W/R 25M05V-702 ✗
37613 Valve Bracket ✗✗ ✗ ✗ ✗
33475 White Rodgers Coil ✗✗ ✗ ✗ ✗ ✗✗
Wires37987 Field Plug Assembly ✗✗
36290 Field Plug Assembly ✗✗ ✗ ✗ ✗
36327 Field Plug Asbly Special (Holiday Rambler) ✗✗ ✗ ✗ ✗
37419 High Tension Wire ✗✗ ✗ ✗ ✗ ✗✗ ✗
37773 Shielded High Tension Wire (optional) No Longer Available
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
48
85-IV 16
85-IV 20
85-IV 25
85-IV 31
85-IV 35
1522 2-stage
2334 2-stage
R-25
Miscellaneous
37844 Air Intake Tube No Longer Available
32882 Door Screen ✗✗ ✗ ✗ ✗ ✗✗
31474 Duct Adapter 4” ✗✗ ✗ ✗ ✗ ✗✗
36688 Duct Adapter 2” ✗✗ ✗ ✗ ✗ ✗✗
31361 Duct Cover Plate ✗✗ ✗ ✗ ✗ ✗✗
37410 Gas Inlet Plug ✗✗ ✗ ✗ ✗ ✗✗
37411 Slide Plate ✗✗ ✗ ✗ ✗ ✗✗
38248 Transformer ✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
49
7912-II
7900-II 16 & 20
8012-II
85-III 16-20
85-III 25
85-III 31-35
89-III DC
89-III AC
2540 2-Stage
Blower
33580 Blower Cover ✗✗✗
34014 Blower Cover ✗✗✗
35881 Blower Wheel ✗✗
33431 Blower Wheel ✗
34550 Blower Wheel ✗✗✗
33126 Blower Wheel Kit ✗✗✗
Burner
36043 Burner ✗✗ ✗
32811 Burner ✗
33842 Burner ✗✗
35491 Burner ✗✗✗
36147 Secondary Air Baffle 7920 & 7916 (after S/N 0651157) ✗
36438 Secondary Air Baffle 7916 (before S/N 0651156) ✗
36258 Secondary Air Baffle 7912, 8012 ✗✗
Burner Orifices
31257 #56 16,000 BTU ✗✗
31265 1.25 MM 18,000 BTU ✗✗
36218 #60 12,000 BTU (before S/N 0651156) No Longer Available
37389 #62 12,000 BTU (after S/N 0651155) ✗✗
31267 #54 25,000 BTU ✗
31280 #52 31,000 BTU ✗
32285 #51 35,000 BTU ✗✗✗
34004 #49 40,000 BTU ✗✗✗
34092 #30 40,000 BTU NAT. ✗
34093 #32 35,000 BTU NAT. ✗
Circuit Board
37966 Controller Module ✗
37984 Controller Module Bracket ✗
37515 Ignition Board Kit (AC) ✗
36716 Ignition Board Kit (DC) ✗✗ ✗ ✗ ✗ ✗✗
38676 Ignition Board Retrofit Kit (with fan control) ✗✗ ✗ ✗ ✗ ✗✗
33686 Ignition Bracket ✗✗✗✗✗✗
37965 Ignition Module ✗
36119 Ign. Plate Metal (before S/N 1165563) ✗✗ ✗
37951 Ign. Plate Plastic (after S/N 1165562) ✗✗ ✗
Circuit Breakers
35791 Breaker 5 AMP ✗✗ ✗ ✗ ✗
37049 Combination Breaker-ON/OFF Switch 5 AMP USE 35791
32331 Breaker 7 AMP Use 33751 ✗✗
33780 Breaker Kit 7 AMP ✗✗
33590 Breaker 10 AMP ✗✗
33781 Breaker Kit 10 AMP ✗✗
34034 Breaker 15 AMP ✗✗
33782 Breaker Kit 15 AMP ✗✗
38507 Breaker 20 AMP ✗
34015 Breaker 20 AMP (without door circuit breaker on/off) ✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
50
7912-II
7900-II 16 & 20
8012-II
85-III 16-20
85-III 25
85-III 31-35
89-III DC
89-III AC
2540 2-Stage
Combustion
35892 Combustion Air Hose ✗✗ ✗
33128 Combustion Wheel Kit ✗✗✗✗✗✗
33124 Combustion Wheel Kit ✗✗ ✗
36216 Metal Combustion Wheel 8535-III Use 37107 ✗
Door 37912 1/4 Turn Nylatch ✗✗ ✗
36644 Access Grill (Screw-In) No Longer Available
37520 Access Grill (1/4 turn fastener) ✗✗ ✗
37864 Access Grill (1/4 turn Artic White) No Longer Available
37760 Clip on Receptacle ✗✗ ✗
31145 Roller Door Catch ✗✗ ✗
Draft Cap
33650 Draft Cap Assembly Adjustable NLA USE 37619 ✗✗✗
38141 Draft Cap 3/8” baffle 8940 8940 ✗
38139 Draft Cap 5/8” baffle 8935 8935
Electrodes
37517 Electrode - single sense ✗✗ ✗
37176 Electrode - single sense (or sub 36999) ✗✗✗
37057 Electrode - single sense ✗✗✗
36998 Electrode - dual sense ✗✗ ✗
36999 Electrode - dual sense ✗✗✗
36997 Electrode - dual sense ✗✗
37079 Electrode Cover Plate (Single Sense) ✗✗ ✗
36044 Electrode Cover Plate (Dual Sense) ✗✗ ✗
Gaskets
35890 Burner Plate Gasket (use 2) ✗✗ ✗
32172 Electrode Gasket Dual Sense ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
37100 Electrode Gasket Single Sense ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
34053 Element Wall Gasket (before SN1259907) ✗✗✗
37956 Element Wall Gasket (after SN1259906) ✗✗✗
32926 Heating Element Gasket ✗✗✗
32841 Motor Gasket ✗✗✗✗✗✗
37661 Motor Gasket ✗✗ ✗
Heating Element
35903 Heating Element ✗✗ ✗
37960 Heating Element Kit* 16, 20, ✗
37961 Heating Element Kit* 25 ✗
37962 Heating Element Kit* 31, 35 ✗
34976 Heating Element ✗✗✗
*Kit includes draft cap & element gasket
Manifolds
33565 Inlet Manifold (before S/N 0654748) ✗✗✗
37392 Outlet Manifold (after S/N 0654747) ✗✗✗
36376 Inlet Manifold (before S/N 0657716) ✗✗✗
37392 Outlet Manifold (after S/N 0657715) ✗✗✗
37391 Outlet Manifold (after S/N 0651155) ✗✗ ✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
51
7912-II
7900-II 16 & 20
8012-II
85-III 16-20
85-III 25
85-III 31-35
89-III DC
89-III AC
2540 2-Stage
33566 Outlet Manifold (before S/N 0654748) ✗✗✗
35936 Outlet Manifold (before S/N 0651156) No Longer Available
31043 Brass Inlet Fitting ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
Use with Part #’s 37392/37391
32173 Brass Inlet Elbow (before S/N 0654748) ✗✗✗
Motor
35122 Motor AC ✗
34039 Motor Capacitor AC ✗
36122 Motor PF20066Q ✗
31036 Motor PF20040Q ✗✗
37964 Motor PF26170Q ✗
37360 Motor Bracket Kit ✗✗✗
35879 Motor Bracket ✗✗ ✗
37359 Motor Kit PF20076Q ✗
37358 Motor Kit PF23190Q ✗
37357 Motor Kit PF26157Q ✗✗
Relay31017 Klixon Relay ✗✗ ✗ ✗ ✗ ✗✗ ✗
Switches
37021 Limit Switch L77 / 170° ✗✗ ✗ ✗ ✗ ✗
37022 Limit Switch L190° ✗✗✗
36121 ON-OFF Switch ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
36133 Sail Switch ✗✗
36134 Sail Switch ✗
36680 Sail Switch (May Use 37716) NLA USE 37716 ✗
35054 Sail Switch ✗
35050 Sail Switch ✗
35137 Sail Switch (May Use 37716) NLA USE 37716 ✗✗✗
36040 Sail Switch Bracket ✗✗ ✗
Thermostats
38452 Thermostat (brown) Heat Only HFH-2000 ✗✗ ✗ ✗ ✗ ✗✗ ✗
38453 Thermostat (white) Heat Only HFH 2000 ✗✗ ✗ ✗ ✗ ✗✗ ✗
38535 Thermostat, Digital, 2 Stage 2H2C ✗
38555 Thermostat, Digital, Single Stage 1H2C ✗✗ ✗ ✗ ✗ ✗✗ ✗
Valve36035 White Rodgers 25M16-503 Side Port ✗✗ ✗
(before S/N 0651156)
37383 White Rodgers Side Outlet ✗✗ ✗
(after S/N 0651155) 25M16V-711
33475 White Rodgers Coil (DC) ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
36036 White Rodgers Valve Bracket ✗✗ ✗
(Use with Part #’s 36035)
37390 White Rodgers Valve Bracket ✗✗ ✗
(Use with Part #’s 37383)
33337 White Rodgers (before S/N 0654748-85 series) ✗✗✗✗
25M16V-701 (before S/N 0657716-89 series)
37383 White Rodgers Side Outlet ✗✗✗
(After Serial #0654747) 25M16V-711
33586 White Rodgers Valve Bracket ✗✗✗✗
(Use with Part # 33337)
37426 White Rodgers Valve Bracket ✗✗✗✗
(Use with Part # 37383)
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
52
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
37383 White Rodgers Valve (DC) (After Serial #0657715) ✗
34006 White Rodgers Valve (AC) (Before Serial #0657716) ✗
25M18V-701
37384 White Rodgers Valve (AC) (After Serial #0657715) ✗
25M18V-711
34515 White Rodgers Coil (AC) ✗
37973 2-Stage Gas Valve W/R 25M05V-701 ✗
Vent Kit
35955 79A-II 4 inch ✗✗ ✗
35956 79B-II 8 inch ✗✗ ✗
35957 79C-II 12 inch ✗✗ ✗
Wires37987 Field Plug Assembly ✗
36290 Field Plug Assembly ✗✗✗
34116 High Tension Lead ✗✗ ✗
35193 High Tension Lead (before S/N 0654748) ✗✗✗
37419 High Tension Lead (after S/N 0654747) ✗✗✗
35193 High Tension Lead (before S/N 0657716) ✗✗
37419 High Tension Lead (after S/N 0657715)) ✗✗✗
37773 Optional Shielded (before S/N 0654747) No Longer Available
37773 Optional Shielded (after S/N 0657715) No Longer Available
36180 Wiring Harness Complete (internal) ✗✗✗
36875 Wiring Harness Complete DC ✗
37443 Wiring Harness Complete AC ✗
Miscellaneous
35121 24 VAC Transformer ✗
36412 Casing Assembly ✗✗
36175 Control Box (Before Serial #0654748) No Longer Available
37427 Control Box (After Serial #0654747) No Longer Available
35912 Control Box ✗✗ ✗
37431 Control Box ✗✗✗
36959 Directional Air Box Insert ✗✗ ✗
31474 Duct Adapter 4” ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
36688 Duct Adapter 2” ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
31361 Duct Cover Plate ✗✗ ✗ ✗ ✗ ✗✗ ✗ ✗
33567 Gas Inlet Plug (Before Serial #0654748) ✗✗✗
37410 Gas Inlet Plug (After Serial #0654747) ✗✗✗
33567 Gas Inlet Plug (Before Serial #0657716) ✗✗✗
37410 Gas Inlet Plug (After Serial #0657715) ✗✗✗
33729 Slide Plate (Before Serial #0654748) ✗✗✗
37411 Slide Plate (After Serial #0654747) ✗✗✗
33729 Slide Plate (Before Serial #0657716) ✗✗
37442 Slide Plate (After Serial #0657715) ✗✗✗
7912-II
7900-II 16 & 20
8012-II
85-III 16-20
85-III 25
85-III 31-35
89-III DC
89-III AC
2540 2-Stage
53
85-II 16-20
85-II 25
85-II 31-35
89-I DC
89-I AC
89-II DC
89-II AC
FA 79D
FA79P
HF 80D
HF 80P
Blower
33580 Blower Cover ✗✗✗
33431 Blower Wheel ✗✗✗✗
33618 Blower Wheel ✗✗
33619 Blower Wheel ✗
34550 Blower Wheel ✗✗✗✗
Burner
32149 Burner No Longer Available
32811 Burner ✗
33842 Burner ✗✗
34000 Burner (Use Kit 38548) ✗✗
35491 Burner ✗✗
Burner Orifice
31268 #59 12,000 BTU ✗✗✗✗
31257 #56 16,000 BTU ✗✗✗
31265 1.25 MM 20,000 BTU ✗✗
31267 #54 25,000 BTU ✗
31280 #52 31 & 32,000 BTU ✗
32285 #51 35,000 BTU ✗✗ ✗✗✗
34004 #49 40,000 BTU ✗✗✗✗
34093 #32 35,000 BTU NAT ✗✗✗✗
34092 #30 40,000 BTU NAT ✗✗✗✗
Circuit Board
33686 Ignition Board Bracket ✗✗✗✗ ✗✗✗
37515 Ignition Board Kit (AC) ✗✗
36716 Ignition Board Kit (DC) ✗✗✗✗ ✗ ✗ ✗
Circuit Breaker
31028 Breaker 5 AMP ✗✗✗✗✗✗✗
32331 Breaker 7 AMP (Use 33751) ✗
33590 Breaker 10 AMP ✗
34034 Breaker 15 AMP ✗✗
Combustion
31881 Combustion Air Hose ✗✗✗✗
33124 Combustion Wheel Kit ✗✗✗✗
33128 Combustion Wheel Kit ✗✗✗✗ ✗✗✗
Door 33753 Deluxe Door 01 White ✗✗✗✗ ✗✗✗
33754 Deluxe Door 02 Colonial White ✗✗✗✗ ✗✗✗
33756 Deluxe Door 04 White ✗✗✗✗ ✗✗✗
33763 Deluxe Door 11 White ✗✗✗✗ ✗✗✗
33764 Deluxe Door 12 Beige No Longer Available ✗✗✗✗ ✗✗✗
35001 Deluxe Door 18 Grey ✗✗✗✗ ✗✗✗
35057 Deluxe Door 20 Grey ✗✗✗✗ ✗✗✗
35101 Deluxe Door 22 White ✗✗✗✗ ✗✗✗
35102 Deluxe Door 23 White ✗✗✗✗ ✗✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
54
85-II 16-20
85-II 25
85-II 31-35
89-I DC
89-I AC
89-II DC
89-II AC
FA 79D
FA79P
HF 80D
HF 80P
33853 Recess Pan 01 White ✗✗✗✗ ✗✗✗
33854 Recess Pan 02 Colonial White ✗✗✗✗ ✗✗✗
33856 Recess Pan 04 White ✗✗✗✗ ✗✗✗
33863 Recess Pan 11 White ✗✗✗✗ ✗✗✗
35063 Recess Pan 12 Grey ✗✗✗✗ ✗✗✗
35104 Recess Pan 22 White ✗✗✗✗ ✗✗✗
35105 Recess Pan 23 White ✗✗✗✗ ✗✗✗
33847 Door Catch Screw Type (set) ✗✗✗✗ ✗✗✗
33620 Door Hinge - inner (set) ✗✗✗✗ ✗✗✗
31145 Roller Door Catch ✗✗✗✗
Draft Cap
34032 Draft Cap Assembly - AC NLA (Use 37890) ✗✗
34030 Draft Cap Assembly - DC NLA (Use 37890) ✗✗
36980 Draft Cap Assembly NLA (USE 37619) ✗✗✗
Electrodes
33234 Electrode ✗✗
36999 Electrode ✗✗✗
34001 Electrode (Use 38548) ✗✗
36997 Electrode ✗✗
36998 Electrode ✗✗
Exhaust Tube Extensions
31680 79/80A (0˝ - 3-1/2˝) NLA ✗✗✗✗
Gaskets
34451 Bottom Discharge Gasket ✗✗✗✗
34553 Bottom Discharge Gasket ✗✗✗
31842 Burner Plate Gasket ✗✗
31843 Burner Plate Gasket ✗✗
33485 Combustion Gasket Set ✗✗✗✗
32172 Electronic Ignition Electrode Gasket ✗✗✗✗ ✗✗✗✗ ✗
32926 Element Gasket ✗✗✗
34053 Element Wall Gasket ✗✗✗✗
32841 Motor Gasket ✗✗✗✗ ✗✗✗
Heating Elements
34976 Heating Element ✗✗✗✗
37960 Heating Element Kit* ✗
37961 Heating Element Kit* ✗
37962 Heating Element Kit* ✗
*Kit includes draft cap & element gasket
Motor
34039 Motor Capacitor AC ✗✗
35122 Motor 7162-2839E AC ✗✗
31035 Motor PF2041Q ✗✗
31036 Motor PF2040Q ✗✗
32774 Motor PF23175Q ✗
33219 Motor PF2055Q ✗
33589 Motor PF23144Q ✗
32870 Motor Bracket ✗✗✗
37357 Motor Kit ✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
55
85-II 16-20
85-II 25
85-II 31-35
89-I DC
89-I AC
89-II DC
89-II AC
FA 79D
FA79P
HF 80D
HF 80P
Pilot 32466 1/4 x 7 Pilot Tube w/ fittings ✗✗
33830 Jade Orifice .008 ✗✗
31307 Jade Thermal Couple 14˝ ✗✗
33831 Jade Pilot Assembly J721013CLP (Use 31299) ✗✗
36038 Piezo Igniter Kit ✗✗✗✗
Relay31017 Klixon Relay ✗✗✗✗ ✗✗✗✗ ✗✗ ✗
Switches
31023 Limit Switch L170 ✗✗✗✗
35132 Limit 130 Switch ✗✗✗✗ ✗
37021 Limit Switch L77-C ✗✗
35047 Sail Switch ✗✗✗✗
35050 Sail Switch ✗
36680 Sail Switch (Use 37716) ✗
35054 Sail Switch ✗
35137 Sail Switch (Use 37716) ✗✗✗✗
36205 Thermal Cut-Off 8900-II ✗✗
Thermostat
38452 Thermostat (brown) heat only ✗✗✗✗ ✗✗✗✗ ✗✗ ✗
38453 Thermostat (white) heat only ✗✗✗✗ ✗✗✗✗ ✗✗ ✗
Valve33716 ITT Valve Retrofit Kit (pilot) ✗✗
33796 ITT/FEN Valve Retrofit Kit (Electronic Ignition) ✗✗
32697 Robertshaw Valve 7000 ERLC-LP ✗✗
33337 White Rodgers Valve 25M16-701 (DC) ✗✗✗✗ ✗ ✗ ✗
33475 White Rodgers Coil (DC) ✗✗✗✗ ✗ ✗ ✗
34006 White Rodgers Valve 25M18-701 (AC) ✗✗
34515 White Rodgers Coil (AC) ✗✗
Wires31090 High Tension Lead No Longer Available
33661 High Tension Lead No Longer Available
35193 High Tension Lead ✗✗✗✗
35235 Wiring Harness Blower AC ✗
Miscellaneous
35121 24 VAC Transformer ✗✗
31361 Duct Cover Plate ✗✗✗✗ ✗✗✗✗ ✗✗ ✗
31474 Duct Adapter ✗✗✗✗ ✗✗✗✗ ✗✗ ✗
33567 Gas Inlet Plug ✗✗✗✗ ✗✗✗
33729 Slide Plate ✗✗✗✗ ✗✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
56
85-1 16-20
85-I 25
85-I 31-35
DC82 25-32
DC82 35-41
AC 82
FA 76D
FA 78 25-32
FA 72D
FA 72P
Blower
31135 Blower Wheel NLA ✗✗
31139 Blower Wheel ✗✗✗ ✗
32775 Blower Wheel ✗✗
32776 Blower Wheel ✗
Burner
32002 Burner ✗✗
32112 Burner ✗✗
32149 Burner No Longer Available
32811 Burner ✗✗✗
Burner Orifice
31270 #66 Orifice ✗✗
31268 #59 Orifice ✗
31257 #56 16,000 BTU ✗
31265 1.25mm 18,000 BTU ✗
31267 #54 25,000 BTU ✗✗ ✗
31280 #52 31 &32,000 BTU ✗✗ ✗
32285 #51 35,000 BTU ✗✗✗ ✗
31256 #50 41,000 BTU ✗✗
32284 #40 35,000 BTU NAT ✗
32238 #36 41,000 BTU NAT ✗
Circuit Breaker
31028 Breaker 5 AMP ✗✗✗✗✗
32331 Breaker 7 AMP (Use 33751) ✗
33590 Breaker 10 AMP ✗✗✗
Circuit Board
36716 Ignition Board Kit (DC) ✗✗✗✗✗ ✗✗✗
37515 Ignition Board Kit (AC) ✗
Combustion
33124 Combustion Wheel Kit ✗✗ ✗
31138 Combustion Wheel No Longer Available
32777 Combustion Wheel NLA (Use 37107) ✗
Electrodes
33234 Electrode ✗
33235 Electrode ✗✗✗ ✗
33625 Electrode Kit ✗✗✗
36999 Electrode Only ✗✗✗
Gaskets
34551 Bottom Discharge Gasket ✗✗✗ ✗
34553 Bottom Discharge Gasket ✗✗✗
31838 Burner Plate Gasket ✗✗
32762 Burner Plate Gasket ✗✗✗ ✗
33485 Combustion Gasket Set ✗
32172 Electronic Ignition Electrode Gasket ✗ ✗✗ ✗✗✗✗ ✗✗
32926 Element Gasket ✗✗✗
31841 Manifold Gasket ✗✗✗ ✗
32841 Motor Gasket ✗✗✗
Heating Elements
32118 Heating Element Assembly ✗✗
32119 Heating Element Assembly ✗✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2003
57
85-1 16-20
85-I 25
85-I 31-35
DC82 25-32
DC82 35-41
AC 82
FA 76D
FA 78 25-32
FA 72D
FA 72P
Motor
31039 Motor JA25065N (AC) ✗
31036 Motor PF2040Q ✗
31037 Motor PE2423Q ✗✗
31038 Motor PE2627Q ✗
32330 Motor PF23129Q ✗✗
32774 Motor PF23175Q ✗✗
33219 Motor PF2055Q ✗
32870 Motor Bracket ✗✗✗
Pilot 31292 ITT Pilot Assembly 26C1762 ✗
33829 ITT TV Orifice .010 ✗✗ ✗
32417 ITT TV Orifice .008 ✗
31299 Jade Pilot Assembly J72C2426CL ✗✗ ✗
32416 Jade Orifice .010 ✗✗ ✗
31307 Jade Thermocouple 14˝ ✗
32480 Jade Thermocouple 18˝ ✗✗ ✗
Relay31017 Klixon Relay ✗ ✗✗ ✗✗✗✗✗
Switch
31023 Limit 170 Switch ✗✗✗
31025 Limit 190 Switch w/plate ✗✗✗ ✗
32927 Limit 190 Switch ✗✗✗
35282 Sail Switch ✗✗✗
33697 Sail Switch ✗✗✗ ✗
Thermostat
38452 Thermostat (brown) heat only ✗ ✗✗ ✗✗✗✗✗✗✗
38453 Thermostat (white) heat only ✗ ✗✗ ✗✗✗ ✗ ✗✗✗
Valves
33717 ITT Valve Retrofit Kit (pilot ✗
33688 ITT/FEN Valve Retrofit Kit (DSI) ✗✗ ✗✗
33797 ITT/FEN Valve Retrofit Kit (DSI) ✗
33806 ITT/FEN Valve Retrofit Kit (DSI) ✗
36728 Johnson Valve Retrofit Kit (DSI) (AC) ✗
33475 White Rodgers Coil ✗✗✗✗✗ ✗
33337 White Rodgers Valve 25M16-701 ✗✗✗✗
Wire 32139 Field Hookup ✗✗ ✗
32140 Field Hookup ✗
Miscellaneous
32475 12 VDC Converter ✗✗✗
31480 24 VAC Transformer (Use 33784) ✗
31831 Door Interior ✗✗✗
33774 Door Catch Assemblies No Longer Available
31474 Duct Adapter ✗ ✗✗ ✗✗✗ ✗
31361 Duct Cover Plate ✗ ✗✗ ✗✗✗ ✗ ✗
32137 Exhaust Tube Ext. 82F (6.5˝-8.5˝) ✗✗✗ ✗
32133 Vent Shell (only) 82BE (3.5˝-6.5˝) ✗✗✗ ✗
32134 Vent Shell (only) 82AD (0˝-3.5˝) ✗✗✗ ✗
hydro flame Furnace
REPLACEMENT PART REFERENCE
September 2002
58
Adapter plate for bottom discharge -
from extension plenum. No seals but with
alignment tabs. Use with extension
plenum 33150 or 37878.
37868
Floor plate and (3) adapters for 4" ducts
to rear of furnace.
34438
Adapter plate for bottom discharge - with foam seals
on both sides.
36278
Adapter plate for bottom discharge - no seals but
with alignment tabs. Use with gasket 34551.
36277
Extension plenum, rear discharge to floor duct
with one seal.
33150
Adapter plate for bottom discharge - same as 36277
except includes foam seals on both sides.
37745
AtwoodFurnaceInstallation
Parts
Part # Appearance Description
Series 85 and 2-Stage Furnaces
Extension plenum, rear discharge to floor duct
with two seals.
37878

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