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 fire, or 2) if continuous fan is active, furnace
lights on high fire for 60 seconds to improve heat exchanger warm up time.
E240
Low flame current - Run mode.
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.
E241
Flame sensed out of sequence - Flame still
present.
Shut off gas. Check for gas valve leak. Replace, if necessary. Alert clears
when fault is recovered.
E250
Limit switch circuit open.
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.
E270
Soft lockout - Exceeded maximum number of
retries. No flame current sensed.
Check for proper gas flow. Ensure that ignitor is lighting burner. Check
flame sensor current. Clears when heat call finishes 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 finishes
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 finishes successfully.
E273
Soft lockout - Exceeded maximum number of
recycles. Last recycle due to flame failure.
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. Clears when heat call finishes
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 firing rate and air flow.
Check for blockage. Clears when heat call finishes successfully.
E275
Soft lockout - Flame sensed out of sequence.
Flame signal is gone.
Shut off gas. Check for gas valve leak. 1-hour soft lockout. Clears when
flame has been proven stable.
Table 4. Integrated Diagnostic Codes / Status of Equipment
