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31-5000723 Rev. 0
Code
Diagnostic Codes / Status of Equipment
Action Required to Clear and Recover
E202
Indoor blower motor mismatch - indoor motor
horsepower does not match unit capacity
Incorrect appliance capacity code selected. Check for
proper configuring under Unit Size Code for Furnace/
Air Handler on configuration guide or in installation
instructions. Cleared after the correct match is detected
following a reset. (Remove thermostat from system
while applying power and reprogramming)
E203
Appliance capacity size is NOT programmed.
Invalid unit codes. Refer to configuration flow chart.
No appliance capacity code selected. Check for proper
configuring under Unit Size Codes for Furnace on
configuration guide or in installation instruction. Critical
Alert Cleared after valid unit code is read following a
reset (remove thermostat from system while applying
power and reprogramming)
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.
E207
Hot surface igniter sensed open - Refer to
troubleshooting
Measure resistance of hot surface igniter. Replace if
open or not within specified range found in installation/
operation manual. Resumes normal operation after fault
is cleared.
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 -Refer to
troubleshooting
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.
E225
High pressure switch failed open -Refer to
troubleshooting
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 -Refer to
troubleshooting
Check operation of high pressure 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. Refer to troubleshooting
Check operation 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.
E228
Combustion air inducer calibration failure
Unable to perform pressure switch calibration. Check
vent system and pressure switch wiring connections.
Resumes normal operation after fault is cleared
E229
Ignition on high fire
IFC switched to high fire ignition because low fire
pressure switch did not close in allowed time. No action
is needed.