Schwank STW-JZ1 - Manual (Page 40)

40
STW-JZ / IW I&O Manual
IM101229
RL: 12A- BA
RD: DEC 2010
MAIN BURNER LIGHTS
SYSTEM RUNS UNTIL CALL FOR HEAT
ENDS
CALL FOR HEAT ENDS:
SYSTEM SHUTS OFF
TROUBLESHOOTING ENDS
 CHECK FOR STRONG SPARK AT IGNITER........
 (SEE PREVIOUS PAGE).
 CHECK FOR 24 VAC ACROSS GAS VALVE.
 CHECK OUTPUT VOLTAGE FROM CONTROL TER-
MINALS TO GAS VALVE.....IF NO VOLTAGE RE-
PLACE CONTROL.
 CHECK ELECTRICAL WIRING, AND VOLTAGE BE-
TWEEN IGNITION CONTROL AND GAS VALVE.
 IF OK, REPLACE GAS VALVE.
NOTE: IF IGNITION CONTROLS GOES INTO A
LOCKOUT, INTERRUPT POWER AND RESTART.
 CHECK CONTINUITY OF SENSOR CABLE AND
GROUND WIRE AS A POOR GROUND COULD RE-
SULT IN ERRATIC BEHAVIOUR AND NUISANCE
SHUTDOWNS EVEN THOUGH OPERATION IS NOR-
MAL AT THE TIME OF CHECKOUT.
 CHECK FOR EXCESSIVE HEAT AT SENSOR INSU-
LATOR AS TEMPERATURES ABOVE 1000°F(538°C)
CAUSES SHORT TO GROUND.
 CHECK FLAME SIGNAL IN SERIES WITH THE
GROUND AND MODULE FOR A MINIMUM 1.5UA.
 IF SIGNAL IS LOWER CHANGE IGNITER.
 IF CHECKS ARE OK.....REPLACE CONTROL.
 CHECK TEMPERATURE CONTROLLER.
 CHECK FOR FAULTY WIRING, REMOVE GAS
VALVE LEAD AT CONTROL ,
 IF VALVE CLOSES, RECHECK THE TEMPERATURE
CONTROLLER AND WIRING.
 IF VALVE STAYS OPEN....REPLACE GAS VALVE
SPARK STOPS WHEN BURNER LIGHTS CONTROL IS NOT SENSING FLAME WITHIN THE
21 SECOND TFI AND IS STILL TRYING TO LIGHT
 CHECK CONTINUITY OF SENSOR CABLE AND
GROUND WIRE
 CHECK BURNER FLAME IS COVERING SENSOR.
 CHECK FLAME SIGNAL IN SERIES WITH THE
GROUND AND MODULE FOR 1.5UA MINIMUM.
 IF SIGNAL IS LOWER CHANGE IGNITER.
 IF CHECKS ARE OK.......REPLACE CONTROL.
NO
YES
NO
YES
YES
YES
NO
NO