Allied 80G2DFE User manual

508189-01 Issue 2116 Page 1 of 42
SERVICE MANUAL
80G2DFE
(P) 508189-01
*P508189-01*
Table of Contents
Technical Specications ..............................................2
Parts Arrangement.......................................................5
Unit Components.........................................................6
Flame Sensor ............................................................16
Gas Valve ..................................................................16
Heating Components.................................................16
Placement and Installation ........................................21
Start-Up .....................................................................21
Heating System Service Checks ...............................22
Typical Operating Characteristics..............................26
Maintenance..............................................................27
Wiring and Sequence of Operation ...........................30
Field Wiring and DIP Switch Settings........................33
Troubleshooting.........................................................37
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to
the potential for personal injury or death.
Electric shock hazard.
Can cause injury or death. Before attempting
to perform any service or maintenance,
turn the electrical power to unit OFF at
disconnect switch(es). Unit may have
multiple power supplies.
WARNING
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves
and protective clothing.
CAUTION
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer (or
equivalent), service agency or the gas supplier.
WARNING

508189-01Issue 2116Page 2 of 42
Technical Specications
MODEL NUMBER GUIDE
PHYSICAL AND ELECTRICAL DATA
Model
High Fire Low Fire
AFUE
(ICUS)
Nom.
Cooling
Capacity
(tons)
Gas
Inlet
(in.)
Volts/
Hz/
Phase
Max.
Overcurrent
Protection
Nominal
F.L.A.
Trans.
(V.A.)
Motor
Output
(hp)
Approx.
Weight
(lbs.)
Input
(Btuh)
Output
(Btuh)
Input
(Btuh)
Output
(Btuh)
DOWNFLOW
80G2DF070AE12 66,000 52,00 43,000 35,000 80.0 3 1/2 120-60-1 15 6.1 40 1/2 123
80G2DF090BE16 88,000 69,000 57,000 46,000 80.0 4 1/2 120-60-1 15 8.2 40 3/4 142
Note: For vent length and clearances to combustibles, please reference installation instructions.
Note: Filters and provisions for mounting are not furnished and must be field provided.
Major Revision
Revision Code
Nom. CFM x 00
12 = 3 Ton add on cooling
16 = 4 Ton add on cooling
20 = 5 Ton add on cooling
Blower Drive
E = Constant Torque ECM
Cabinet Width
A = 14.5” width
B = 17.5” width
C = 21.0” width
AFUE
80 = 80% Efficency
Gas
Stages
2 = Two Stage
Configuration
DF = Downflow
BTUH Input
Heating Input x 1000
80 G 2 UH 110 C E 16 -01

508189-01 Issue 2116 Page 3 of 42
80G2DF090BE16
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.10 1700 423 1495 293 1380 233 1295 202 1165 156
0.20 1665 436 1455 307 1330 248 1245 211 1110 166
0.30 1620 452 1415 319 1295 257 1195 221 1055 175
0.40 1585 464 1365 328 1225 269 1140 230 985 185
0.50 1560 471 1325 343 1185 277 1090 240 930 193
0.60 1455 475 1275 355 1120 290 1025 252 875 202
0.70 1405 482 1235 365 1075 295 990 259 840 209
0.80 --- --- 1160 369 1025 308 925 268 780 217
BLOWER PERFORMANCE
80G2DF070AE12
External
Static
Pressure
in. w.g.
Air Volume / Watts at Various Blower Speeds
High
(Black)
Medium-High
(Brown)
Medium
(Blue)
Medium-Low
(Yellow)
Low
(Red)
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1475 346 1345 269 1190 192 970 109 785 71
0.10 1440 355 1325 276 1165 198 935 114 775 74
0.20 1410 365 1280 287 1135 207 905 120 740 79
0.30 1260 401 1250 296 1095 216 855 129 665 86
0.40 1355 380 1225 305 1060 223 815 134 615 92
0.50 1320 394 1200 315 1035 229 770 140 580 97
0.60 1290 401 1160 324 1005 237 745 149 465 105
0.70 1260 410 1130 333 970 245 700 155 445 108
0.80 1215 399 1095 341 935 254 660 158 400 113

508189-01Issue 2116Page 4 of 42
ACCESSORIES
Accessory Catalog Number
Return Air Base
Return Air Base 14.5” 68W61
Return Air Base 17.5” 68W62
Return Air Base 21.0” 68W62
High Altitude Pressure Switches
2-Stage 80% UH/DF (4501 - 7500 ft) [045, 070, 090 110] 91W53
2-Stage 80% UH/DF (7501 - 10,000 ft) [045, 070, 090 110] 73W35
High Altitude Orice Kits (7500 ft+)
2-Stage 80% UH/DF - Natural Gas 51W01
2-Stage 80% UH/DF - Propane Gas 11K47
Natural to LP Kits
2-Stage 80% UH/DF (0 - 7500 ft) 11K48
2-Stage 80% UH/DF (7501 - 10,000 ft) 11K47
LP to Natural Kits
2-Stage 80% UH/DF 77W10
Downow Specic Air Filters
14.5" 51W06
17.5" 51W07
Downow Combustible Flooring Base
14.5" 11M59
17.5" 11M60
Night Service Kits
2-Stage 22J94
Horizontal Suspension Kit
80% & 90% 51W10
External Filter Rack Kits
1 pack (16 x 25) 1.841018
10 pack (16 x 25) 1.841039
Twinning Kit
Constant Torque Gas Furnace Twinning Kit 16W72
For vent length and clearances to combustibles, please reference installation instructions.

508189-01 Issue 2116 Page 5 of 42
Parts Arrangement
Figure 1.
Control Box
(includes integrated control,
transformer and door switch)
Secondary Limit
Internal Flue Pipe Assembly
Gas Valve
Burner Box Assembly
Combustion
Air Inducer
Indoor Blower
Heat Exchanger
Primary Limit
Top Cap

508189-01Issue 2116Page 6 of 42
Unit Components
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
Electrostatic discharge can a󰀨ect electronic
components. Take precautions to
neutralize electrostatic charge by touching
your hand and tools to metal prior to
handling the control.
CAUTION
80G2DFE unit components are shown in Figure 1. The gas
valve, combustion air inducer and burners can be accessed
by removing the access panel. Electrical components are
in the control box (Figure 2) found in the blower section.
80G2DFE units are factory equipped with a bottom return
air panel in place. The panel is designed to be eld removed
as required for bottom air return. Markings are provided for
side return air and may be cut out in the eld.
Control Box Components (Figure 2)
Transformer
Circuit Breaker
Integrated
Control
Interlock Switch
Figure 2. Control Box
Transformer (T1)
A transformer located in the control box provides power
to the low voltage section of the unit. Transformers on all
models are rated 40VA with a 120V primary and a 24V
secondary.
Door Interlock Switch (S51)
A door interlock switch is wired in series with line voltage.
When the inner blower access panel is removed the unit
will shut down.
Circuit Breaker (CB8)
A 24V circuit breaker is also located in the control box. The
switch provides overcurrent protection to the transformer
(T1). The breaker is rated at 3A at 32V. If the current
exceeds this limit the breaker will trip and all unit operation
will shutdown. The breaker can be manually reset by
pressing the button on the face. See Figure 3.
Figure 3. Circuit Breaker (CB8)
PRESS TO RESET
Integrated Ignition Control (A92)
Shock hazard.
Disconnect power before servicing.
Control is not eld repairable. If control is
inoperable, simply replace entire control.
Can cause injury or death. Unsafe
operation will result if repair is attempted.
WARNING
Units are equipped with a two-stage, integrated control.
The system consists of a ignition / blower control (Figure
4 and Figure 5) with control pin designations in Table 1
and Table 2 and ignitor. The control and ignitor work
in combination to ensure furnace ignition and ignitor
durability. The control provides gas ignition, safety checks
and indoor blower control with two-stage gas heating.
The furnace combustion air inducer, gas valve and indoor
blower are controlled in response to various system inputs
such as thermostat signal, pressure and limit switch signal
and ame signal. The control features a seven-segment
LED display, indicating furnace status and error codes.
The LED ashes in single digits. For example, using Table
4 under LIMIT CODE, an “E” followed by “2” followed by “5”
followed by “0”, the limit switch circuit is open. The control
also has two unpowered (dry) 1/4” contacts for a humidier
and a 120 volt accessory terminal. Both rated at (1) one
amp each.

508189-01 Issue 2116 Page 7 of 42
Pin # Function
1Ignitor
2Combustion Air Inducer High Speed
3Combustion Air Inducer Low Speed
4Combustion Air Inducer Neutral
5Ignitor Neutral
Table 1. 5-Pin Terminal Designations
Pin # Function
1Gas Valve Second Stage
2Second Stage Pressure Switch
3Rollout Switch In
4Ground
524V Hot
6Primary Limit In
7Gas Valve First Stage
8Gas Valve Common
924V Neutral
10 Ground
11 Primary Limit Out
12 First Stage Pressure Switch
Table 2. 12-Pin Terminal Designations
Electric Shock Hazard.
Can cause injury or death. Unit must be
properly grounded in accordance with
national and local codes.
WARNING
Fire Hazard.
Use of aluminum wire with this product may result in a
re, causing property damage, severe injury or death.
Use copper wire only with this product.
WARNING
Electronic Ignition
At the beginning of the heat cycle the integrated control
monitors the rst stage and second stage combustion air
inducer pressure switch. The control will not begin the
heating cycle if the rst stage pressure switch is closed
(bypassed). Likewise the integrated control will not begin
the second stage heating cycle if the second stage
pressure switch is closed, and will remain in rst stage
heat. However, if the second stage pressure switch closes
during the rst stage heat pre-purge, the control will allow
second stage heat. Once the rst stage pressure switch
is determined to be open, the combustion air inducer is
energized on low (rst stage) heat speed. When the
di󰀨erential in the pressure switch is great enough, the
pressure switch closes and a 15-second pre-purge begins.
After the 15-second pre-purge period, the ignitor warms
up for 20 seconds after which the gas valve opens for a
4-second trial for ignition. The ignitor remains energized
during the trial until ame is sensed. If ignition is not proved
during the 4-second period, the control will try four more
times with an inter purge and warm-up time between trials
of 35 seconds. After a total of ve trials for ignition (including
the initial trial), the control goes into Watchguard-Flame
Failure mode. After a 60-minute reset period, the control
will begin the ignition sequence again.
NOTE: During abnormal conditions such as low supply
voltage or low outdoor temperatures and the low re
pressure switch does not close, the combustion air inducer
will switch to high speed. After the low & high pressure
switch close, the unit will proceed with a 15 sec pre-purge,
followed by a 20 sec ignitor warm up, then ignition on
highre. After 10 to 20 seconds of high re operation the
unit will switch to low re.
Two Stage Operation / Thermostat Selection DIP
Switch
The control can be utilized in two modes: SINGLE-STAGE
thermostat or TWO-STAGE thermostat. The thermostat
selection is made using a DIP switch and must be positioned
for the particular application. DIP switch 1, labeled T”STAT
HEAT STAGE is factory-set in the OFF position for use
with a two-stage thermostat. Move the DIP switch to ON
for use with a single stage thermostat.
While in the single-stage thermostat mode, the burners will
always re on rst-stage heat. The combustion air inducer
will operate on low speed and indoor blower will operate on
low heat speed. The unit will switch to second stage heat
after a “recognition period”. DIP switch 2, labeled SECOND
STAGE DELAY, is factory set in the OFF position for a 7
minute recognition period. The switch can be moved to the
ON position for a 12 minute recognition period, after which
time the unit will switch to second-stage heat.
While in the two-stage thermostat mode, the burners will
re on rst-stage heat. The combustion air inducer will
operate on low speed and indoor blower will operate on low
heat speed. The unit will switch to second-stage heat on
call from the indoor thermostat. If there is a simultaneous
call for rst and second stage heat, the unit will re on
rst stage heat and switch to second stage heat after 30
seconds of operation. See Sequence of Operation ow
charts in the back of this manual for more detail.

508189-01Issue 2116Page 8 of 42
Figure 4. Integrated Control
Flame Sense
S4 DIP Switches
24VAC Indoor
Blower Terminals
HUM ACC
Ignitor and Combustion
Air Inducer
Neutrals
On Board Links
LED
Diagnostic Push
Button
3/16” QUICK CONNECT TERMINALS
FLAME SENSE SIGNAL
HI COOL 24VAC
LO COOL 24VAC
LO HEAT 24VAC
PARK
PARK
COMMON 24VAC
1/4” QUICK CONNECT TERMINALS
NEUTRALS = 120 VAC NEUTRAL
HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS
LI = 120VAC INPUT TO CONTROL
A
CC = 120VAC OUTPUT TO OPTIONAL ACCESSORY
THERMOSTAT CONNECTIONS (TB1)
DS = DEHUMIDIFICATION SIGNAL
W2 = HEAT DEMAND FROM 2ND STAGE TSTAT
W1 = HEAT DEMAND FROM 1ST STAGE TSTAT
R = CLASS 2 VOLTAGE TO TSTAT
G = MANUAL FAN FROM TSTAT
C = TSTAT SIGNAL GROUND CONNECTED TO
TRANSFORMER GRD (TR) & CHASSIS GROUND (GRD)
Y1 = TSTAT 1ST STAGE COOL SIGNAL
Y2 = TSTAT 2ND STAGE COOL SIGNAL
O = TSTAT SIGNAL TO HEAT PUMP REVERSING VALVE
DH = NOT USED
L = NOT USED

508189-01 Issue 2116 Page 9 of 42
Figure 5. Integrated Control Conguration Guide
HEATING BLOWER−OFF DELAY
60 SECOND
HTG BLOWER
OFF DELAY
120 SECOND
HTG BLOWER
OFF DELAY
180 SECOND
HTG BLOWER
OFF DELAY
FLAME
15
HSI/CAI
2ND STAGE HEAT ON DELAY
7 MIN
UPSTAGE
DELAY
12 MIN
UPSTAGE
DELAY
*
W915
2 STAGE
COMPR
1−STG COMPRESSOR
2−STAGE
COMPRESSOR LINK
(JUMPERS Y1 to Y2)
W915
DO NOT CUT
2−STG COMPRESSOR
HEAT PUMP LINK
(JUMPERS R to O)
W951
(JUMPERS R to DS)
W914
W915
2 STAGE
COMPR
CUT LINK
A/C UNIT
DO NOT CUT
HEAT PUMP UNIT
CUT LINK
W951
HEAT
PUMP
W951
HEAT
PUMP
W914
DEHUM
NO SIGNATURESTAT
W/ DS CONNECTION
DO NOT CUT
SIGNATURESTAT W/
DS CONNECTION
CUT LINK
W914
DEHUM
1
1
1
ON−BOARD LINK
OPTION SELECTION
1234567
1234567
123567
4
123567
4
NEUTRALS
L1
ACC
HUM
14
36
P79
110
312
J2
4 7
W915
2 STAGE
COMPR
W951
HEAT
PUMP
W914
DEHUM
CUT FOR
OPTION
SELECTION
123456
ON
W1W2 GY2 Y1 CC DH LODSR
W1 W2
G
Y2
Y1
C C
R
L
DH
7
1
ON
ON
ON
ON
90 SECOND
HTG BLOWER
OFF DELAY
*1234567
ON
1234567
ON
THERMOSTAT SELECTION
1−STAGE
THERMOSTAT
(TIMED STAGING)
−SEE SW #2
TWO STAGE
THERMOSTAT
*
1234567
1234567
ON
ON
−BLOWER ON DELAY − 30 SEC. FIXED
1234567
ON
SENSE
IGN
CAI2
CAI1
N N
J3
S1
S4S3
DIAGNOSTIC
LED
DIAGNOSTIC
PUSH BUTTON
*45 SECOND
COOL BLOWER
OFF DELAY
2 SECOND
COOL BLOWER
OFF DELAY
123567
4
123567
4
ON
ON
COOLING BLOWER-OFF DELAY
1234567
ON
1234567
ON
1234567
ON
CONTINUOUS FAN SETTINGS
LOW HEAT SPEED
LOW COOL SPEED
HIGH HEAT SPEED
HIGH COOL SPEED
DEHUMIFICATION LINK
- CUT ON-BOARD LINK (SOLDER TRACE)
COMPLETELY THROUGH BOTH LAYERS ON THE
CONTROL BOARD
- LINKS CUT IN ERROR - INSTALL A JUMPER ON THE
APPROPRIATE TERMINALS ON THE TERMINAL
STRIP
- PROTECTIVE PLASTIC FILM ON DIP SWITCHES
MAY BE REMOVED FOR EASE IN SETTING OF DIP
SW.
* FACTORY DEFAULT

508189-01Issue 2116Page 10 of 42
Display Action (when button released)
No change (idle)* Remain in idle mode
Solid “E” Enter diagnostic recal mode
Solid “F” Enter ame signal mode
* No change implies the display will continue to show whatever is currently being displayed for normal operation (blinking decimal,
active error code, heat state, etc.)
Table 3. Integrated Control Diagnostic Modes
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
.Idle mode (Decimal blinks at 1 Hertz -- 0.5
second ON, 0.5 second OFF).
CCooling stage (1 second ON, 0.5 second OFF)
1 or 2 displayed / Pause / Repeat codes.
d Dehumidication mode (1 second ON, 1
second OFF) / Pause / Repeat Codes).
HGas Heat Stage (1 second ON, 0.5 second
OFF) 1 or 2 displayed / Pause / Repeat codes.
Blinking during ignition.
hHeat pump stage.
E110 Low line voltage. Line Voltage Low (Voltage lower than nameplate rating). Check power line
voltage and correct. Alarm clears 5 seconds after fault recovered.
E111 Line voltage polarity reversed. Reverse line power voltage wiring. System resumes normal operation 5
seconds after fault recovered.
E112 Ground not detected. System shuts down. Provide proper earth ground. System resumes normal
operation 5 seconds after fault recovered.
E113 High line voltage. Line Voltage High (Voltage higher than nameplate rating). Provide power
voltage within proper range. System resumes normal operation 5 seconds
after fault recovered.
E114 Line voltage frequency out-of-range. No 60 Hertz Power. Check voltage and line power frequency. Correct
voltage and frequency problems. System resumes normal operation 5
seconds after fault recovered.
E115 Low 24V - Control will restart if the error
recovers.
24-Volt Power Low (Range is 18 to 30 volts). Check and correct voltage.
Check for additional power-robbing equipment connected to system. May
require installation of larger VA transformer to be installed in furnace / air
handler. Clears after fault recovered.
E117 Poor ground detected (Warning only) Provide proper grounding for unit. Check for proper earth ground to the
system. Warning only will clear 30 seconds after fault recovered.
E125 Control failed self-check, internal error,
failed hardware. Will restart if error recovers.
Integrated control not communicating. Covers
hardware errors (ame sense circuit faults, pin
shorts, etc.).
Hardware problem on the control. Cycle power on control. Replace if
problem prevents service and is persistent. Critical alert. Cleared 300
seconds after fault recovered.
E200 Hard lockout - Rollout circuit open or previously
open.
Correct cause of rollout trip, or replace ame rollout switch. Test furnace
operation. Cleared after fault recovered.
E204 Gas valve mis-wired. Check gas valve operation and wiring. Clears when repaired.
E205 Gas valve control relay contact shorted. Check wiring on control and gas valve. If wiring is correct, replace control.
E206 Gas valve second-stage relay failure. Furnace will operate on 1st stage for remainder of the heating demand.
Will clear after fault recovered. If unable to operate 2nd stage, replace
control.
E207 Hot surface ignitor sensed open. Measure resistance of hot surface ignitor. Replace if open or not within
specied range found in IOM. Resumes normal operation after fault is
cleared.
Table 4. Integrated Diagnostic Codes / Status of Equipment

508189-01 Issue 2116 Page 11 of 42
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
E223 Low pressure switch failed open. Check pressure (inches w.c.) of low pressure switch closing on heat call.
Measure operating pressure (inches w.c.). Inspect vent and combustion
air inducer for correct operation and restriction. Resumes normal operation
after fault is cleared
E224 Low pressure switch failed closed. Check operation of low pressure switch to see if it is stuck closed on
heat call longer than 150 seconds. Measure operating pressure (inches
w.c.). Inspect vent and combustion air inducer for correct operation and
restriction. Resumes normal operation after fault is cleared.
E225 High pressure switch failed open. Check pressure (inches w.c.) of high pressure switch closing on heat call.
Measure operating pressure (inches w.c.). Inspect vent and combustion air
inducer for correct operation and restriction. Resumes normal operation
after fault is cleared.
E226 High pressure switch failed closed. Check operation of high pressure switch closing on heat call. Measure
operating pressure (inches w.c.). Inspect vent and combustion air inducer
for correct operation and restriction. Resumes normal operation after fault
is cleared.
E227 Low pressure switch open during trial for
ignition or run mode.
Check pressure (inches w.c.) of low pressure switch closing on heat call.
Measure operating pressure (inches w.c.). Inspect vent and combustion
air inducer for correct operation and restriction. Resumes normal operation
after fault is cleared.
E229 Ignition on High Fire - Information Only. Code is displayed if 1) low pressure switch fails to close, then furnace will
switch to high speed inducer to close both low and high pressure switches,
then furnace lights on high re, or 2) if continuous fan is active, furnace
lights on high re for 60 seconds to improve heat exchanger warm up time.
E240 Low ame current - Run mode. Check micro-amperes of ame sensor using control diagnostics or eld-
installed mode. Clean or replace sensor. Measure voltage of neutral to
ground to ensure good unit ground. Alert clears after current heat call has
been completed.
E241 Flame sensed out of sequence - Flame still
present.
Shut o󰀨 gas. Check for gas valve leak. Replace, if necessary. Alert clears
when fault is recovered.
E250 Limit switch circuit open. Check for proper ring rate on furnace. Ensure there is no blockage in
heater. Check for proper air ow. If limit not closed within 3 minutes, unit will
go into 1-hour soft lockout. Resumes normal operation after fault is cleared.
E270 Soft lockout - Exceeded maximum number of
retries. No ame current sensed.
Check for proper gas ow. Ensure that ignitor is lighting burner. Check
ame sensor current. Clears when heat call nishes successfully.
E271 Soft lockout - Exceeded maximum number of
retries. Last retry failed due to the pressure
switch opening.
Check pressure (inches w.c.) of low pressure switch closing on heat call.
Measure operating pressure (inches w.c.). Inspect vent and combustion air
inducer for correct operation and restriction. Clears when heat call nishes
successfully.
E272 Soft lockout - Exceeded maximum number
of recycles. Last recycle due to the pressure
switch opening.
Check operation of low pressure switch to see if it is stuck closed on
heat call. Check pressure (inches w.c.) of high pressure switch closing
on heat call. Measure operating pressure (inches w.c.). Inspect vent and
combustion air inducer for correct operation and restriction. Clears when
heat call nishes successfully.
E273 Soft lockout - Exceeded maximum number of
recycles. Last recycle due to ame failure.
Check micro-amperes of ame sensor using control diagnostics or eld-
installed mode. Clean or replace sensor. Measure voltage of neutral
to ground to ensure good unit ground. Clears when heat call nishes
successfully.
E274 Soft lockout - Exceeded maximum number of
recycles. Last recycle failed due to the limit
circuit opening or limit remained open longer
than 3 minutes.
Shut down system. 1-hour soft lockout. Check ring rate and air ow.
Check for blockage. Clears when heat call nishes successfully.
E275 Soft lockout - Flame sensed out of sequence.
Flame signal is gone.
Shut o󰀨 gas. Check for gas valve leak. 1-hour soft lockout. Clears when
ame has been proven stable.
Table 4. Integrated Diagnostic Codes / Status of Equipment

508189-01Issue 2116Page 12 of 42
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
E290 Ignitor circuit fault - Failed ignitor or triggering
circuitry.
Measure resistance of hot surface ignitor. Replace if open or not within
specications. 1-hour soft lockout. Clears when ame has been proven
stable.
Table 4. Integrated Diagnostic Codes / Status of Equipment
Diagnostic LED (Figure 4)
The seven-segment diagnostic LED displays operating
status, error codes and other information. Table 4 lists
diagnostic LED codes.
Diagnostic Push Button (Figure 4)
The diagnostic push button is located adjacent to the seven-
segment diagnostic LED. This button is used to enable
the Error Code Recall “E” mode and the Flame Signal “F”
mode. Press the button and hold it to cycle through a menu
of options. Every ve seconds a new menu item will be
displayed. When the button is released, the displayed item
will be selected. Once all items in the menu have been
displayed, the menu resumes from the beginning until the
button is released.
Error Code Recall Mode
Select ”E” from the menu to access the most recent 10
error codes. Select “c” from the Error Code Recall menu
to clear all error codes. Button must be pressed a second
time while “c” is ashing to conrm command to delete
codes. Press the button until a solid “≡” is displayed to exit
the Error Code Recall mode.
Flame Signal Mode
Select ”F” from the menu to access the ame signal mode.
The integrated control will display the ame current on
seven-segment LED in in micro amps (uA).
Flame signal mode is exited after any of the following:
• Power is reset
• Pressing and holding push button until 3 horizontal
lines “≡” are displayed
• 10 minutes after entering the ame sense mode.
Integrated Control DIP Switches
Integrated Control DIP Switches
80G2DFE units are equipped with a two-stage integrated
control. This control manages ignition timing, heating
mode fan o󰀨 delays and indoor blower speeds based on
selections made using the control dip switches and jumpers.
The control includes an internal watchguard feature which
automatically resets the ignition control when it has been
locked out. After one hour of continuous thermostat
demand for heat, the watchguard will break and remake
thermostat demand to the furnace and automatically reset
the control to relight the furnace.
Heating Operation DIP Switch Settings
Switch 1 -- Thermostat Selection -- This unit may be
used with either a single-stage or two-stage thermostat.
The thermostat selection is made using a DIP switch which
must be properly positioned for the particular application.
The DIP switch is factory-positioned for use with a twostage
thermostat. If a single-stage thermostat is to be used, the
DIP switch must be repositioned.
a. Select “OFF” for two-stage heating operation
controlled by a two-stage heating thermostat
(factory setting);
b. Select “ON” for two-stage heating operation
controlled by a single-stage heating thermostat.
This setting provides a timed delay before second-
stage heat is initiated.
Switch 2 --- Second Stage Delay (Used with Single-
Stage Thermostat Only) -- This switch is used to determine
the second stage on delay when a single-stage thermostat
is being used. The switch is factory-set in the OFF position,
which provides a 7-minute delay before second-stage heat
is initiated. If the switch is toggled to the ON position, it
will provide a 12-minute delay before second-stage heat is
initiated. This switch is only activated when the thermostat
selector jumper is positioned for single-stage thermostat
use.

508189-01 Issue 2116 Page 13 of 42
Indoor Blower Operation DIP Switch Settings
Switches 3 and 4 -- Heating Mode Blower-O󰀨 Delay --
The blower-on delay of 30 seconds is not adjustable. The
blower-o󰀨 delay (time that the blower operates after the
heating demand has been satised) can be adjusted by
moving switches 3 and 4 on the integrated control. The
unit is shipped from the factory with a blower-o󰀨 delay
of 90 seconds. The blower o󰀨 delay a󰀨ects comfort and
is adjustable to satisfy individual applications. Adjust
the blower o󰀨 delay to achieve a supply air temperature
between 90° and 110°F at the exact moment that the blower
is de-energized. Longer o󰀨 delay settings provide lower
supply air temperatures; shorter settings provide higher
supply air temperatures. Table 5 provides the blower o󰀨
timings that will result from di󰀨erent switch settings.
Blower O󰀨 Delay
(seconds) Switch 3 Switch 4
60 On O󰀨
90 (Factory) O󰀨 O󰀨
120 O󰀨 On
180 On On
Table 5. Blower O󰀨 Heating Mode Delay Switch
Settings
Switch 5 -- Cooling Mode Blower-O󰀨 Delay -- The unit
is shipped from the factory with the dip switch positioned
OFF for a 45 second delay. Table 6 provides the cooling
mode o󰀨 delay settings.
Blower O󰀨 Delay
(seconds) Switch 5
45 (Factory) O󰀨
2On
Table 6. Blower O󰀨 Cooling Mode Delay Switch
Settings
Switches 6 and 7 -- Continuous Fan Mode -- Continuous
fan speed can be controlled by changing DIP switch
positions. Table 7 provides DIP switch settings for
continuous fan mode.
Continuous Fan
Mode Switch 6 Switch 7
Low Heat Speed
(Factory) O󰀨 O󰀨
Low Cool Speed O󰀨 On
High Heat Speed On O󰀨
High Cool Speed On On
Table 7. Continuous Fan Mode Settings
Onboard Links
W914 Dehum
Onboard link W914, is a clippable connection between
terminals R and DS on the integrated control. W914 must
be cut when the furnace is installed with a thermostat which
features humidity control. If the link is not cut, terminal “DS”
will remain energized not allowing the blower to reduce to
low cool speed upon a call for dehumidication.
W951 Heat Pump (R to O)
Onboard link W951 is a clippable connection between
terminals R and O on the integrated control. W951 must
be cut when the furnace is installed in applications which
include a heat pump unit and a thermostat which features
dual fuel use. If the link is left intact, terminal “O” will remain
energized eliminating the HEAT MODE in the heat pump.
W915 2 Stage Compr (Y1 to Y2)
Onboard link W915 is a clippable connection between
terminals Y1 and Y2 on the integrated control. W915 must
be cut if two-stage cooling will be used. If the Y1 to Y2
link is not cut the outdoor unit will operate in second-stage
cooling only.
If any onboard link is cut by mistake, install a jumper
across the corresponding terminals on the low voltage
terminal strip. Do not replace control.
IMPORTANT

508189-01Issue 2116Page 14 of 42
Blower Compartment
Each blower is statically and dynamically balanced as
an assembly before installation in the unit.
IMPORTANT
Secondary Limit Control (S21)
The secondary limit (S21) is located in the blower
compartment. See Figure 1. When excess heat is sensed
in the blower compartment, the limit will open. If the limit is
open, the furnace control energizes the supply air blower
and closes the gas valve. The limit automatically resets
when unit temperature returns to normal. The switch
must reset within three minutes or the control will go into
Watchguard for one hour. The switch is factory set and
cannot be adjusted.
80G2DFE units are equipped with a constant torque ECM
motor. It has a DC motor coupled to an electronic control
module both contained in the same motor housing. The
motor is programmed to provide constant torque at each of
the ve selectable speed taps. Each tap requires 24 volts
to energize.
Input Voltage Requirements
The circuit is designed to be operated with AC voltage. To
enable a tap requires 12 to 33VAC. Expected current draw
will be less than 20mA.
Troubleshooting the Motor
Troubleshooting the motor is an easy process. Follow
steps below.
1. Shut o󰀨 power to unit.
2. Remove input plugs P48 and P49 from motor. See
Figure 8 for troubleshooting procedure.
If correct voltage is present in tests 1 and 2 and motor is
not operating properly, replace motor. The motor is not eld
repairable.
If replacing the indoor blower motor or blower wheel is
necessary, placement is critical. The blower wheel must
be centered in the blower housing as shown in Figure 6.
When replacing the indoor blower motor the set screw
must be aligned and tightened with the motor shaft as
shown in Figure 7.
Figure 6. Blower Wheel Replacement
Center Blower Wheel
in Blower Housing
Figure 7.
Set Screw
Housing Hub
ALIGN AND TIGHTEN SET SCREW WITH
FLAT SIDE OF MOTOR SHAFT
Motor
Shaft

508189-01 Issue 2116 Page 15 of 42
Figure 8.
1
2
3
4
5
C
L
G
N
Multi−Meter
(set to VAC)
P48
P49 24
Test 1
Test 2
Test 3 (if necessary)
Test 4 (if necessary)
1
2
3
4
5
C
L
G
N
Multi−Meter
(set to VAC)
P48
P49
120 120
Multi−Meter
(set to VAC)
120 120
24
Multi−Meter
(set to VAC)
Turn on power to unit. Check for 120 volts across terminals
“L” and “N” on input plug P48. If voltage is present continue
to test 2. If voltage is not present, problem may be upstream
of plug P48 and proceed to test 3.
Check for 120 volts across terminals “L1” and “Neutrals” on
the integrated control. If voltage is present, problem is with
the harness. If voltage is not present problem may be may
be with the integrated control.
Switch thermostat to CONTINUOUS FAN MODE. Check for
24 volts across terminal “C” on input plug P48 and speed
tap used for continuous fan (1, 2, 3, 4 or 5) on input plug
P49. If 24 volts is not present, problem may be upstream of
plug P49. Proceed to test 4.
Check for 24 volts across terminals “24 COM” and the
“active speed trap” on the integrated control. If voltage is
present, problem is with the harness. If voltage is not
present, problem may be may be with the integrated
control.

508189-01Issue 2116Page 16 of 42
Heating Components
Ignitor
The ignitor is made of durable silicon nitride. The integrated
control provides 120 volts to the ignitor for a consistent
ignition and long ignitor life. Ohm value should be 39 to 70.
See Figure 9 for ignitor location and Figure 10 for ignitor
check out.
NOTE: The 80G2DFE furnace contains electronic
components that are polarity sensitive. Make sure that the
furnace is wired correctly and is properly grounded.
Flame Sensor
A ame sensor is located on the left side of the burner
support. See Figure 9. The sensor tip protrudes into the
ame envelope of the left-most burner. The sensor can
be removed for service without removing any part of the
burners. During operation, ame is sensed by current
passed through the ame and sensing electrode. The
control allows the gas valve to remain open as long as
ame signal is sensed. To check ame sense signal use
the push-button found on the integrated control and go to
Field Test Mode. The menu will display the ame signal.
See Table 8 for ame signal.
To Measure Flame Signal - Integrated Control:
Use a digital readout meter capable of reading DC
microamps. See Figure 11 and Table 8 for ame signal
check.
1. Set the meter to the DC amps scale.
2. Turn o󰀨 supply voltage to control.
3. Disconnect integrated control ame sensor wire from
the ame sensor.
4. Connect (-) lead to ame sensor.
5. Connect (+) lead to the ignition control sensor wire.
6. Turn supply voltage on and close thermostat contacts
to cycle system.
7. When main burners are in operation for two minutes,
take reading.
Normal Low Drop Out
2.6 or greater 2.5 or less 0.06
Table 8. Flame Signal in Microamps
Gas Valve
The valve (Figure 13) is internally redundant to assure
safety shut-o󰀨. If the gas valve must be replaced, the same
type valve must be used.
24VAC terminals and gas control knob are located on the
valve. A wire harness connects the terminals from the gas
valve to the electronic ignition control. 24V applied to the
terminals energizes the valve.
Inlet and outlet pressure taps are located on the valve. A
regulator adjustment screw is located on the valve.
LPG change over kits are available from Allied. Kits include
burner orices and a gas valve.
Flame Rollout Switches (S47)
Flame rollout switch is a high temperature limit located on
top of the burner box, one on each side.- See Figure 9.
The limit is a N.C. SPST manual-reset limit. When S47
senses rollout, the circuit breaks and the ignition control
immediately stops ignition and closes the gas valve.
Rollout can be caused by a blocked exchanger, ue or lack
of combustion air. The switch is factory set to trip (open) at
210°F and cannot be adjusted. The switch can be manually
reset. To manually reset a tripped switch, push the reset
button located on the control.
Burners
All units use inshot burners. Burners are factory set and
require no adjustment. Always operate the unit with the
burner box front panel in place. Each burner uses an orice
that is precisely matched to the burner input. Burners can
be removed as a one piece assembly for service. If burner
assembly has been removed, it is critical to align center
of each burner to the center of the clamshell when re-
installing. See more detail in the Maintenance section.
Primary Limit Control (S10)
The primary limit (S10) is located in the heating vestibule
panel. When excess heat is sensed in the heat exchanger,
the limit will open. If the limit is open, the furnace control
energizes the supply air blower and closes the gas valve.
The limit automatically resets when unit temperature
returns to normal. The switch must reset within three
minutes or the control will go into Watch guard for one
hour. The switch is factory set and cannot be adjusted. The
switch may have a di󰀨erent set point for each unit model
number.

508189-01 Issue 2116 Page 17 of 42
Figure 9. Heating Components
Ignitor Burners
Sensor
Gas Valve
Manifold and Gas Orifices
Rollout Switch

508189-01Issue 2116Page 18 of 42
Figure 10. Ignitor Check Out
Integrated Control Board
Detail
Integrated Control Board
Detail
Integrated Control Board
Detail
Test 3
Check ignitor for correct voltage
Insert meter probes into terminals 1 and 5 (use small
diameter probes in order not to damage plug).
Check voltage during 20 second ignitor warm up period.
Voltage should read 120 volts + 10%. If voltage reads below
these values, check for correct supply voltage to furnace.
Meter
(set to AC volts)
Test 2
Check ignitor for correct resistance.
Seperate the 2−pin jack−plug near the manifold and check
resistance of ignitor at the plug. Reading should be
between 39 and 70 ohms. If the reading is correct, then
the problem is with the wiring between the jack−plug and
the control. If reading is not correct, the issue is the ignitor.
Meter
(set to ohms)
Test 1
Check ignitor circuit for correct resistance.
Remove 5−pin plug from control.
Check ohms reading across terminals 1 and 5.
If value is correct, this is the only test needed.
If the reading on the meter is not correct, (0 or infinity)
then a second test is needed.
Meter
(set to ohms)

508189-01 Issue 2116 Page 19 of 42
Figure 11. Measuring Flame Signal
Set dial to measure
DC microamps
(+)
To Flame
Terminal
DIGITAL METER
Red Collar
Indicates
Positive Leads
(+) To Control
Sensor Terminal
Flame
Sensor
Flame Sensor
Wire
Integrated
Control
Remove Sensor Wire from
Integrated Control and
Connect Alligator Clip (−)
to Frame Sensor Lead
Flame Sensor
Terminal
Remove Sensor Wire from
Integrated Control and
Connect Alligator Clip (+)
to Terminal on Control
(+)

508189-01Issue 2116Page 20 of 42
Combustion Air Inducer (B6) and Cold End Header Box
All 80G2DFE units use a two-speed combustion air inducer
to move air through the burners and heat exchanger during
heating operation. The blower uses a 120VAC motor.
The motor operates during all heating operation and is
controlled by integrated control control A92. The inducer
also operates for 15 seconds before burner ignition (pre-
purge) and for 5 seconds after the gas valve closes (post-
purge). The inducer operates on low speed during rst-
stage heat, then switches to high speed for second stage
heat.
The combustion air inducer is installed on the cold end
header box (CEHB). The cold end header box is a single
piece made of hard plastic. The box has an internal
channel where the combustion air inducer creates negative
pressure at unit start up. The channel contains an orice
used to regulate ow created by the combustion air inducer.
The box has pressure taps for the combustion air inducer
pressure switch hoses. The pressure switch measures the
pressure di󰀨erential across the cold end header box orice
or di󰀨erence in the channel and the box. If replacement
is necessary the gaskets used to seal the box to the
vestibule panel and the combustion air inducer to the
box, must also be replaced.
A pressure switch measures the pressure di󰀨erential across
the CEHB orice to prove inducer operation. The CEHB
orice will be di󰀨erent for each model. When the proving
switch opens, the furnace control (A92) immediately closes
the gas valve to prevent burner operation.
Combustion Air Inducer Pressure Switch (S18) (Figure
12)
80G2DFE series units are equipped with a dual combustion
air pressure switch (rst and second stage) located on the
CEHB. The switch is connected to the cold end header box
by means of exible silicone hoses. It monitors negative
di󰀨erential pressure across the cold end header box orice.
The switches are a single-pole single-throw pressure
switches electrically connected to the integrated control.
The purpose of the switches is to prevent burner operation
if the combustion air inducer is not operating, the inlet or
exhaust pipes or heat exchanger are restricted.
On heat demand (rst or second stage) the switch senses
that the combustion air inducer is operating. It closes a
circuit to the integrated control when pressure across the
CEHB orice becomes greater then the switch set point.
Set points vary depending on unit size. See Table 9. Both
pressures sensed by the switches are negative relative to
atmospheric pressure. If the inlet or exhaust pipes, or the
heat exchanger become obstructed, the switch senses the
loss of di󰀨erential pressure and opens the circuit to the
furnace integrated control and gas valve. A bleed port on
the switch allows relatively dry air in the vestibule to purge
switch tubing, to prevent condensate build up.
Figure 12. Combustion Air Inducer Pressure Switch
Tap
High Fire
Switch Low Fire
Switch
Bracket
3/16” terminals
1/4“ terminals
NOTE: The switch is factory set and is not eld adjustable.
It is a safety shut-down control in the furnace and must
not be by-passed for any reason. If switch is closed or
bypassed, the control will not initiate ignition at start up.
Unit
Set Point
Low Heat
(in. w.c.)
Set Point
High Heat
(in. w.c.)
-070 0.25 0.55
-090 0.25 0.55
Table 9. 0 - 4,500 ft.
NOTE: See Table 13 for high altitude pressure switch kits.