Page 52
SureLight
®
Troubleshooting: Continuous Fan Sequence of Operation
SURELIGHT CONTROL
CONTINUOUS FAN SEQUENCE OF OPERATION
DS1 & DS2: SLOW FLASH RATE REMAINS
UNCHANGED THROUGHOUT SEQUENCE.
MANUAL FAN SELECTION MADE AT THERMOSTAT.
CONTROL (G) ENERGIZES INDOOR BLOWER AT
FAN SPEED. EAC TERM. IS ENERGIZED.
THERMOSTAT CALLS FOR HEAT (W).
THERMOSTAT CALLS FOR COOLING.
THERMOSTAT OPENS. COMBUSTION AIR INDUCER
AND HUM TERMINALS ARE DE−ENERGIZED
FOLLOWING 5−SECOND POST−PURGE.
INDOOR BLOWER SWITCHES TO COOL SPEED.
THERMOSTAT OPENS.
INDOOR BLOWER SWITCHES TO SELECTED
BLOWER SPEED. EAC TERM. REMAINS
ENERGIZED.
NO
YES
YES
NO
HUM (120 VAC & 24VAC)
TERMINALS ENERGIZED
WITH COMB. AIR INDUCER.
INDOOR BLOWER SWITCHES TO HEAT SPEED
AFTER NORMAL DELAY.
INDOOR BLOWER SELECTED TIME OFF DELAY BEGINS.
AFTER DELAY, HEAT SPEED DE−ENERGIZED.
(Blower remains energized during continuous fan mode).
Ignition Control Board Diagnostic Codes
DIAGNOSTIC CODES
Make sure to Identify LED’S Correctly.
Refer to Installation Instructions for control board layout.
DS1
(Red or Green)
DS2
(Green)
DESCRIPTION
SIMULTANEOUS
SLOW FLASH
SIMULTANEOUS
SLOW FLASH
Power on −− Normal operation.
Also signaled during cooling and continuous fan.
SIMULTANEOUS
FAST FLASH
SIMULTANEOUS
FAST FLASH
Normal operation −− Signaled when heating demand initiated at thermostat.
SLOW FLASH
ON
Primary or secondary limit switch open. Limit must close within 3 minutes or unit goes into
1−hour Watchguard.
OFF
SLOW FLASH
Pressure switch open;
OR: Blocked inlet/exhaust vent;
OR: Condensate line blocked;
OR: Pressure switch closed prior to activation of combustion air inducer.
ALTERNATING
SLOW FLASH
ALTERNATING
SLOW FLASH
Watchguard −− Burners failed to ignite, limit open longer than 3 minutes, or flame sense lost 5
times in one heating cycle.
SLOW FLASH
OFF
Flame sensed without gas valve energized.
ON
SLOW FLASH
Rollout switch open.
ON
ON
OFF
ON
OFF
ON
Circuit board failure or control wired incorrectly. Check 24−volt and 115−volt connections to
board.
FAST FLASH
SLOW FLASH
Main power polarity reversed. Switch line and neutral. Improper main ground.
SLOW FLASH
FAST FLASH
Low flame signal. Check flame sensor.
ALTERNATING
FAST FLASH
ALTERNATING
FAST FLASH
The following conditions are sensed during the ignitor warm−up period only:
1) Improper main ground;
2) Broken ignitor; OR: Open ignitor circuit;
3) Line voltage below 75 volts.
NOTE
− Slow flash rate equals 1 Hz (one flash per second). Fast flash rate equals 3 Hz (three flashes per second).
Drop out flame sense current = 0.15 − 0.24 microAmps.
