Lennox SLP99UHV Series Unit Information page 31

Integrated Control Diagnostic Codes (Continued)
Code Diagnostic Codes/Status of Equipment
E200 Hard lockout - Rollout circuit open or previously
open.
E201 Indoor blower communication failure - Unable to
communicate with blower motor.
E202 Indoor blower motor mis-match - Indoor
motor horsepower does not match unit
capacity.
E203 Appliance capacity / size is NOT
programmed. Invalid unit codes refer to
configuration flow chart in installation
instructions.
E204 Gas valve mis-wired.
E205 Gas valve control relay contact shorted.
E207 Hot surface ignitor sensed open - Refer to
troubleshooting in installation instruction.
E223 Low pressure switch failed open - Refer to
troubleshooting in installation instruction.
E224 Low pressure switch failed closed - Refer to
troubleshooting in installation instruction.
E225 High pressure switch failed open - Refer to
troubleshooting in installation instruction.
E226 High pressure switch failed closed - Refer to
troubleshooting in installation instruction.
E227 Low pressure switch open during trial for
ignition or run mode. Refer to troubleshooting
in installation instruction.
Unable to perform successful pressure switch
E228
calibration.
Low flame current - Run mode - Refer to
E240
troubleshooting in installation instruction.
E241 Flame sensed out of sequence - Flame still
present.
E250 Limit switch circuit open - Refer to
troubleshooting in installation instruction.
E252 Discharge air temperature too high (gas heat
only).
Soft lockout - Exceeded maximum number of
E270
retries. No flame current sensed.
E271 Soft lockout - Exceeded maximum number of
retries. Last retry failed due to the pressure
switch opening.
E272 Soft lockout - Exceeded maximum number
of recycles. Last recycle due to the pressure
switch opening.
E273 Soft lockout - Exceeded maximum number of
recycles. Last recycle due to flame failure.
Action Required to Clear and Recover
Correct unit cause of rollout trip or replace flame rollout switch and test furnace
operation.
Indoor blower communication failure including power outage.
Incorrect furnace size code selected. Check unit size codes on
configuration guide or in installation instructions.
No furnace size code selected. Check unit size codes on configuration
guide or in installation instructions.
Check operation of gas valve.
Check operation of gas valve.
Measure resistance of Hot Surface Ignitor, replace if open or not within
specification.
Check inches of water column pressure during operation of low pressure
switch on heat call, measure inches of water column of operating
pressure, inspect vent and combustion air inducer for correct operation
and restriction.
Check low pressure switch for closed contacts, measure inches of water
column of operating pressure, inspect vent and combustion air inducer
for correct operation and restriction.
Check inches of water column pressure of high pressure switch on heat
call, measure inches of water column of operating pressure, inspect vent
and combustion air inducer for correct operation and restriction.
Check high pressure switch for closed contacts, measure inches of
water column of operating pressure, inspect vent and combustion air
inducer for correct operation and restriction.
Check inches of water column pressure during operation of low pressure
switch on heat call, measure inches of water column of operating
pressure, inspect vent and combustion air inducer for correct operation
and restriction.
Retry after 300 seconds. Error counter cleared when exiting lockout,
unable to perform pressure switch calibration. Check vent system and
pressure switch wiring connections.
Check micro amperes of flame sensor, clean or replace sensor. Measure
voltage of neutral to ground for good unit ground.
Shut off gas, check for gas valve leak.
Check why limit is tripping, overfired, low air flow.
Check temperature rise, air flow and input rate.
Check for gas flow, ignitor lighting burner, flame sensor current.
See E 223.
See E 223 and E 225.
See E 240.
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