Lennox A98USMV Installation Instructions Manual page 61

Code Diagnostic Codes / Status of Equipment
E207 Hot surface igniter sensed open - Refer to
troubleshooting
E223 Low pressure switch failed open
E224 Low pressure switch failed closed -Refer to
troubleshooting
E225 High pressure switch failed open -Refer to
troubleshooting
E226 High pressure switch failed closed -Refer to
troubleshooting
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.
508364-01
Action Required to Clear and Recover
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.
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.
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.
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.
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.
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.
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