Troubleshooting - Lennox G40DF Series 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
NORMAL OPERATION:
LED #1 −− SLOW FLASH
LED #2 −− SLOW FLASH
THERMOSTAT CALLS FOR HEAT:
LED #1 −− FAST FLASH
LED #2 −− FAST FLASH
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
NO
IS VOLTAGE
ABOVE 90 VOLTS?
YES
YES
BURNER OFF?
YES
YES
YES
CLOSED?
YES
IS COMBUSTION AIR
YES
ENERGIZED?
YES
YES
ABNORMAL HEATING MODE
GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER DELAY OFF.
NO
(RESET CONTROL BY TURNING MAIN POWER OFF.)
NO
POLARITY REVERSED.
LED #1 −− FAST FLASH
LED #2 −− SLOW FLASH
NO
LED #1 −− ALTERNATING FAST FLASH
LED #2 −− ALTERNATING FAST FLASH
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
FOR MINIMUM OF 1 SECOND.
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
NO
INDOOR BLOWER ON HEATING SPEED.
LED #1 −− SLOW FLASH
COMBUSTION AIR INDUCER OFF.
LED #1 SLOW FLASH RATE
NO
COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER OFF WITH DELAY.
NO
(Sequence holds until pressure switch
opens or thermostat resets control.)
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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LED #1 ON
LED #2 ON
IMPROPER GROUND.
INDOOR BLOWER ON.
LED #2 −− OFF
INDOOR BLOWER ON
LED #2 −− ON
GAS VALVE OFF.
LED #1 OFF
LED #2 SLOW FLASH
YES