Allied A80US2VX - Page 13

508033-02 Issue 2135 Page 13 of 48
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.
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 re IFC switched to high re ignition because low re pressure switch did not
close in allowed time. No action is needed.
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.
E252 Discharge air temperature too high (gas
heat only).
Check temperature rise, air ow and input rate. Cleared when heat call is
nished.
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.
Table 5. Integrated Diagnostic Codes/Status of Equipment