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TABLE 5 Continued
Code
Diagnostic Codes/Status of Equipment
Action Required to Clear and Recover
E 271
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 in
ducer for correct operation and restriction. Clears
when heat call finishes successfully.
E 272
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 opera
tion and restriction. Clears when heat call finishes
successfully.
E 273
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.
E 274
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.
E 275
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.
E 276
Watchguard calibration failure.
Unable to perform pressure switch calibration.
Check vent system and pressure switch wiring con
nections. 1-hour soft lockout. Clears when calibra
tion has finished successfully.
E 290
Ignitor circuit fault - Failed ignitor or triggering circuitry.
Measure resistance of hot surface ignitor. Replace if
open or not within specifications. 1-hour soft lock
out. Clears when flame has been proven stable.
E 291
Heat air flow restricted below the minimum.
Check for dirty filter and air flow restriction. Check
blower performance. 1-hour soft lockout. Cleared
when heat call finishes successfully.
E 292
Indoor blower motor unable to start due to obstructed wheel, seized
bearings.
Indoor blower motor unable to start (seized bear
ing, stuck wheel, etc.). Replace motor or wheel if
assembly does not operate or meet performance
standards. 1-hour soft lockout. Clears after circula
tor successfully starts.
E 294
Combustion air inducer over current.
Check combustion blower bearings, wiring and
amps. Replace if does not operate or does not meet
performance standards. Clears after inducer current
is sensed to be in-range after the ignition following
the soft lockout or reset.
E 295
Indoor blower motor temperature is too high.
Indoor blower motor over temperature (motor
tripped on internal protector). Check motor bearings
and amps. Replace if necessary. Cleared after
blower demand is satisfied.
E 310
Discharge error temperature sensor failure. Only shown if shorted or
out of range.
Compare outdoor sensor resistance to temperature/
resistance charts in installation instructions. Re
place sensor if necessary. Cleared in Communicat
ing mode: 30 seconds after fault recovered. In Non-
Communicating mode: Cleared after the current
heat call is completed.
E 311
Heat rate reduced to match indoor blower air flow.
Warning Only. Furnace blower in cutback mode due
to restricted airflow. Reduce firing rate every 60
seconds to match available CFM. Check filter and
duct system. To clear, replace filter if needed or re
pair/add duct. 2-stage controls will reduce firing rate
to 1
st
stage. Clears when heat call finishes success
fully.
