Lennox SL280DFV Installation Instructions Manual page 51

Integrated Control Diagnostic Codes (continued)
Code Diagnostic Codes/Status of Equipment
E 223
Low pressure switch failed open.
E 224
Low pressure switch failed closed − Refer to troubleshooting. See
Page 56.
E 225
High pressure switch failed open − Refer to troubleshooting. See
Page 56.
E 226
High pressure switch failed closed − Refer to troubleshooting. See
Page 56.
E 227
Low pressure switch open during trial for ignition or run mode. Refer to
troubleshooting. See Page 56.
E 228
Combustion air inducer calibration failure
E 229
Ignition on high fire
E 240
Low flame current − Run mode − Refer to troubleshooting. See Page 56.
E 241
Flame sensed out of sequence − Flame still present.
E 250
Limit switch circuit open − Refer to troubleshooting.
E 252
Discharge air temperature too high (gas heat only).
E 270
Soft lockout − Exceeded maximum number of retries. No flame current
sensed.
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. Re-
sumes normal operation after fault is cleared
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 opera-
tion and restriction. Resumes normal operation after
fault is cleared.
Check pressure (inches w.c.) of high pressure
switch closing on heat call. Measure operating pres-
sure (inches w.c.). Inspect vent and combustion air
inducer for correct operation and restriction. Re-
sumes normal operation after fault is cleared.
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 opera-
tion 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 in-
ducer for correct operation and restriction. Re-
sumes normal operation after fault is cleared.
Unable to perform pressure switch calibration.
Check vent system and pressure switch wiring con-
nections. 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 en-
sure good unit ground. Alert clears after current
heat call 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, air flow and input rate.
Cleared when heat call is finished.
Check for proper gas flow. Ensure that ignitor is
lighting burner. 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 combustion air in-
ducer for correct operation and restriction. Clears
when heat call finishes successfully.
Page 51
Action Required to Clear and Recover