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SureLight Troubleshooting: Heating Sequence of Operation (Continued)
HEATING SEQUENCE OF OPERATION
LOW FLAME SIGNAL
(Does not affect control operation)
DS1 SLOW FLASH, DS2 FAST FLASH.
FLAME SIGNAL ABOVE
(
u
0.2 microamps)
NO
YES
CONTINUED ON NEXT PAGE
YES
SINGLE-STAGE THERMOSTAT MODE
(E20 SET AT SINGLE")
TWO STAGE THERMOSTAT MODE
(E20 SET AT TWO")
YES
YES
START SECOND-STAGE RECOGNITION
ON DELAY (10 OR 15 MINUTES).
DS1 AND DS2 SIMULTANEOUS FAST FLASH.
45-SECOND INDOOR BLOWER ON DELAY BEGINS.
DS1 AND DS2 SIMULTANEOUS FAST FLASH.
YES
YES
PRIMARY LIMIT AND
ROLLOUT SWITCH CLOSED?
NO
GAS VALVE OFF, COMBUSTION AIR INDUCER OFF,
INDOOR BLOWER ON. DS1 SLOW FLASH, DS2 ON,
ON/OFF LED ON, HEAT LED ON.
HAS PRIMARY LIMIT OR ROLLOUT
SWITCH CLOSED WITHIN 3 MINUTES?
(Indoor blower on low speed during 3-minute period)
YES
FIRST-STAGE (LOW FIRE)
PRESSURE SWITCH CLOSED?
LIMIT SWITCH WATCHGUARD MODE.
GAS VALVE OFF, COMBUSTION AIR INDUCER OFF,
INDOOR BLOWER OFF WITH DELAY.
DS1 AND DS2 ALTERNATING SLOW FLASH,
ON/OFF LED OFF, HEAT LED OFF.
IS 60-MINUTE RESET PERIOD COMPLETE?
THERMOSTAT CALLS FOR HEAT.
DS1 AND DS2 SIMULTANEOUS FAST FLASH.
SEE BOX A.
NO
YES
GAS VALVE OFF. COMBUSTION AIR INDUCER ON.
INDOOR BLOWER OFF AFTER DELAY.
DS1 OFF, DS 2 SLOW FLASH,
ON/OFF LED OFF, HEAT LED ON.
NO
YES
C
FIRST-STAGE HEAT DEMAND SATISFIED?
DS1 AND DS2 SIMULTANEOUS SLOW FLASH.
GAS VALVE OFF, COMBUSTION AIR INDUCER
OFF FOLLOWING POST PURGE.
INDOOR BLOWER OFF WITH DELAY
DS1 AND DS2 SIMULTANEOUS SLOW FLASH
YES
SECOND-STAGE HEAT DEMAND.
SECOND-STAGE HEAT DEMAND REQUIRED?
DS1 AND DS2 SIMUTANEOUS SLOW FLASH.
NO
SECOND STAGE PRESSURE SWITCH CLOSED?
ABNORMAL FLASH CODE.
NOTE - IF SECOND-STAGE PRESSURE SWITCH
WAS ORIGINALLY FOUND CLOSED,
ABNORMAL CODE WILL FLASH.
SECOND-STAGE PRESSURE SWITCH CLOSED
AT BEGINNING OF HEAT DEMAND?
DS1 OFF, DS2 SLOW FLASH,
ON/OFF LED ON, HEAT LED ON.
YES
NO
SECOND-STAGE 30-SECOND DELAY ON BEGINS.
DS1 AND DS2 SIMULTANEOUS FAST FLASH
SECOND-STAGE COMBUSTION AIR INDUCER
ON. SECOND-STAGE GAS VALVE ON. HIGH
HEAT INDOOR BLOWER SPEED ON.
DS1 AND DS2 SIMULTANEOUS FAST FLASH.
ON/OFF LED ON.
YES
SECOND-STAGE PRESSURE SWITCH CLOSED
IN LESS THAN TEN (10) SECONDS?
DS1 AND DS2 SIMULTANEOUS FAST FLASH.
YES
NO
RETURNS TO FIRST-STAGE HEAT MODE WHICH
CONTINUES UNTIL SECOND-STAGE PRESSURE
SWITCH CAN BE PROVEN or HEAT DEMAND IS
SATISFIED. FIVE (5) MINUTE WAIT PERIOD
INITIATED BEFORE RETRY. WERE 5 ATTEMPTS
MADE FOR SECOND-STAGE HEAT?
YES
NORMAL OPERATION.
DS1 AND DS2 SIMULTANEOUS SLOW FLASH.
SECOND STAGE HEAT DEMAND
DS1 AND DS2 SIMULTANEOUS SLOW FLASH.
NO
YES
NO
YES
CONTINUED
