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TABLE 4 Continued
E 270
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.
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 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.
