Allied Air A96US2V Installation Instructions Manual page 70

Integrated Control Diagnostic Modes (Continued)
Code Diagnostic Codes/Status of Equipment Action Required to Clear and Recover
E227 Low pressure switch open during
trial for ignition or run mode. Refer to
troubleshooting
E228 Combustion air inducer calibration
failure
E229 Ignition on high fire
E240 Low flame current - Run mode- Refer
to troubleshooting
E241 Flame sensed out of sequence-Flame
still present.
E250 Limit switch circuit open - Refer to
troubleshooting.
E252 Discharge air temperature too high
(gas heat only).
E270 Soft lockout - Exceeded maximum
number of retries. No flame current
sensed.
E271 Soft lockout - Exceeded maximum
number of retries. Last retry failed
due to the pressure switch opening.
E272 Soft lockout - Exceeded maximum
number of recycles. Last recycle due
to the pressure switch opening
E273 Soft lockout - Exceeded maximum
number of recycles. Last recycle due
to flame failure
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.
E275 Soft lockout - Flame sensed out of
sequence. Flame signal is gone.
E276 Watchguard calibration failure.
E290 Ignitor circuit fault - Failed ignitor or
triggering circuitry.
Page 70 of 80
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.
Unable to perform pressure switch calibration. Check vent system and
pressure switch wiring connections. Resumes normal operation after
fault is cleared
IFC switched to high fire ignition because low fire pressure switch did
not close in allowed time. No action is needed.
Check micro-amperes of flame sensor using control diagnostics or field
installed mode. Clean or replace sensor. Measure voltage of neutral to
ground to ensure good unit ground. Alert clears after current heat all
has been completed.
Shut off gas. Check for gas valve leak. Replace if necessary. Alert
clears when fault is recovered.
Check for proper firing rate on furnace. Ensure there is no blockage in
heater. Check for proper air flow. If limit not closed within 3 minutes
unit will go into 1 hour soft lockout. Resumes normal operation after
fault is cleared.
Check temperature rise airflow and input rate. Clear when heat call is
finished.
Check for proper gas flow. Ensure that igniter is lighting burners. Check
flame sensor current. Clears when heat call finishes successfully.
Check pressure (inches w.c.) of low pressure switch closing on heat
call. Measure operating pressure (inches w.c.). Inspect vent and com-
bustion air inducer for correct operation and restriction. Clears when
heat call finishes successfully.
Check operation of low pressure 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. Inspect vent and combustion
air inducer for correct operation and restriction. Clears when heat call
finishes successfully.
Check micro-amperes of flame sensor using control diagnostics or field
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.
Shut down system 1-hour soft lockout. Check firing rate and air flow.
Check for blockage. Clears when heat call finishes successfully.
Shut off gas. Check for gas valve leak. 1-hour soft lockout. Clears
when flame has been proven stable.
Unable to perform pressure switch calibration. Check vent system and
pressure switch wiring connections. 1-hour soft lockout. Clears when
calibration has finished successfully.
Measure resistance of hot surface igniter. Replace if open or not within
specifications. 1-hour soft lockout. Clears when flame has been proven
stable.
Issue 1621 507404-04