LAARS 9600 CB & HWG - Service Manual - Manual (Page 15)

9600 CB & HWG Service Manual
Page 15
SECTION 2.
Troubleshooting
(Detailed Flow Charts on Page 16-22)
If the burner “locks out” for any reason, the
cause of failure will be displayed by the flashing of one
of the lights.
2A. Code
GREEN “POWER” - Light flashing - control
failure, no light, no power
RED “PURGE” - Light flashing - blower or
stack switch failure or possible flue blockage.
RED “VALVE/FLAME” - Light flashing - valve,
igniter or flame sense failure (combustion related
problem).
Normal Operation.
Note: If the stack switch contacts are closed for
any reason when the blower isn’t operating, a sequence
will not occur and after 45 seconds the control will
“lock out” and the “PURGE” light will flash. If the
stack switch contacts are open and do not close during
purge period, after 5 minutes the control will lock out
and the “PURGE” light will flash. If the boiler does not
operate, the green “POWER” light is on and no
indicator lights are flashing, check for an open vent
TCO, operating control or safety limit switch. For
additional troubleshooting information refer to the
trouble shooting flow charts on the pages that follow.
POWER
ON THERMOSTAT
CALL FOR HEAT
THERMOSTAT
CALL FOR
HEAT ENDS
STANDBY PROVE NO
AIRFLOW
PROVE
AIRFLOW
PREPURGE WARMUP TRIAL FOR
IGNITION
RUN POST
PURGE
STANDBY
45
SEC
MAX
5
MIN
MAX
15
SEC
20
SEC
8
SEC
30
SEC
POWER LED
AQUASTAT/AUXILIARY
LIMITS
CIRCULATOR
AIR PROVING SWITCH
COMBUSTION
AIR BLOWER
PURGE LED
IGNITER
PROOF OF FLAME
IGNITER LED
GAS CONTROL
VALVE/FLAME LED
1
3
3
CLOSED
CLOSED OPEN
2
2 SEC
AP
1 SEC
1 POWER LED BLINKS ONCE WHEN 24V POWER IS APPLIED AND WHEN THE THERMOSTAT CALLS FOR HEAT.
2 ON AS LONG AS CONTROL IS POWERED AND OPERATING PROPERLY.
3 IF EITHER SWITCH OPENS DURING THE RUN CYCLE, BURNER WILL STOP, FOLLOWED BY POSTPURGE.
CIRCULATOR WILL RUN AS LONG AS THERMOSTAT IS CALLING FOR HEAT. BURNER IGNITION SEQUENCE
WILL RESTART IF SWITCH CLOSES.