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HEATING SEQUENCE OF OPERATION
NORMAL HEATING MODE
ABNORMAL HEATING MODE
CONTROL SELF−CHECK OKAY?
BURNER OFF?
(CONTINUOUS FLAME CHECK)
NORMAL OPERATION:
LED #1 −− SLOW FLASH
LED #2 −− SLOW FLASH
YES
YES
YES
GAS VALVE OFF. COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER DELAY OFF.
LED #1 ON
LED #2 ON
(RESET CONTROL BY TURNING MAIN POWER OFF.)
POLARITY REVERSED.
LED #1 −− FAST FLASH
LED #2 −− SLOW FLASH
POWER ON
IS POLARITY REVERSED?
ROLLOUT SWITCH CLOSED?
THERMOSTAT CALLS FOR HEAT:
LED #1 −− FAST FLASH
LED #2 −− FAST FLASH
IS COMBUSTION AIR
PROVE SWITCH OPEN?
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
INDOOR BLOWER ON.
LED #1 −− ON. LED #2 −− SLOW FLASH.
SEQUENCE HOLDS UNTIL ROLLOUT SWITCH CLOSES.
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
INDOOR BLOWER ON HEATING SPEED.
LED #1 −− SLOW FLASH
LED #2 −− OFF
GAS VALVE OFF.
COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER OFF WITH DELAY.
LED #1 OFF
LED #2 SLOW FLASH
(Sequence holds until pressure switch
closes or thermostat resets control.)
NO
NO
YES
NO
IS VOLTAGE
ABOVE 75 VOLTS?
LED SIGNALS WAITING ON CALL FROM
THERMOSTAT. CONTROL WILL NOT RESPOND
UNTIL VOLTAGE RISES ABOVE 75 VOLTS.
NO
NO
NO
IS COMBUSTION AIR INDUCER
ENERGIZED?
HAS COMBUSTION AIR PROVE SWITCH
CLOSED IN 2.5 MINUTES?
YES
YES
PROVE SWITCH IS IN WATCHGUARD MODE.
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?
NO
PRIMARY AND SECONDARY LIMIT SWITCH.
CLOSED?
YES
YES
CONTINUED NEXT PAGE
COMBUSTION AIR INDUCER OFF.
INDOOR BLOWER ON
LED #1 SLOW FLASH RATE
LED #2 −− ON
NO
YES
YES
NO
YES
