Troubleshooting - Lennox G43UF Installation Instructions Manual

Troubleshooting: Heating Sequence of Operation
NORMAL HEATING MODE
CONTROL SELF−CHECK OKAY?
IS POLARITY CORRECT?
IS THERE A PROPER GROUND?
ROLLOUT SWITCH CLOSED?
(CONTINUOUS FLAME CHECK)
NO
LED #1 −− SLOW FLASH
LED #2 −− SLOW FLASH
THERMOSTAT CALLS FOR HEAT:
PRIMARY AND SECONDARY LIMIT SWITCH.
PRESSURE SWITCH OPEN?
IS COMBUSTION AIR INDUCER
HAS COMBUSTION AIR PRESSURE
SWITCH CLOSED IN 2.5 MINUTES?
CONTINUED NEXT PAGE
HEATING SEQUENCE OF OPERATION
POWER ON
YES
YES
YES
IS VOLTAGE
ABOVE 90 VOLTS?
YES
YES
BURNER OFF?
YES
NORMAL OPERATION:
YES
LED #1 −− FAST FLASH
LED #2 −− FAST FLASH
YES
CLOSED?
YES
IS COMBUSTION AIR
YES
ENERGIZED?
YES
YES
ABNORMAL HEATING MODE
GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.
NO
(RESET CONTROL BY TURNING MAIN POWER OFF.)
NO
NO
LED #1 −− ALTERNATING FAST FLASH
LED #2 −− ALTERNATING FAST FLASH
NO
LEDs SIGNAL FAST ALTERNATING FLASH.
CONTROL WILL NOT RESPOND TO A CALL FOR
HEATING UNTIL VOLTAGE RISES ABOVE 95 VOLTS.
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
NO
LED #1 −− ON. LED #2 −− SLOW FLASH.
SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES
AND POWER IS RESET OR T'STAT IS INTERRUPTED
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
NO
INDOOR BLOWER ON HEATING SPEED.
NO
NO
PRESSURE SWITCH IS IN WATCHGUARD MODE.
NO GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER OFF WITH DELAY.
LED #1 −− OFF. LED #2 −− SLOW FLASH.
IS 5-MINUTE RESET PERIOD COMPLETE?
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INDOOR BLOWER DELAY OFF.
LED #1 ON
LED #2 ON
POLARITY REVERSED.
LED #1 −− FAST FLASH
LED #2 −− SLOW FLASH
IMPROPER GROUND.
INDOOR BLOWER ON.
FOR MINIMUM OF 1 SECOND.
LED #1 −− SLOW FLASH
LED #2 −− OFF
COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER ON
LED #1 SLOW FLASH RATE
LED #2 −− ON
GAS VALVE OFF.
COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER OFF WITH DELAY.
LED #1 OFF
LED #2 SLOW FLASH
(Sequence holds until pressure switch
opens or thermostat resets control.)
YES