Advertisement
START
REVIEW NORMAL
OPERATING SEQUENCE.
TURN GAS SUPPLY ON.
TURN THERMOSTAT UP
TO CALL FOR HEAT.
NO
POWER TO S89 (24 VAC
AND 120 VAC NORMAL)
YES
S89E - 10 SEC. MAX.
NO
DELAY FOR SAFE
START CHECK
S89F ONLY—
38 SECOND MAXIMUM
VALVE-ON DELAY
YES
NO
SPARK ACROSS
IGNITER GAP
YES
NO
MAIN BURNER LIGHTS
YES
NO
SPARK STOPS BEFORE
END OF IGNITER TIMING
YES
NO
SYSTEM RUNS UNTIL
CALL FOR HEAT ENDS
YES
CALL FOR HEAT ENDS;
NO
SYSTEM SHUTS OFF
YES
TROUBLESHOOTING ENDS
S89E,F DIRECT SPARK IGNITION CONTROL MODULE
CHECK LINE VOLTAGE POWER. LOW VOLTAGE TRANSFORMER,
LIMIT CONTROLLER, THERMOSTAT AND WIRING. ALSO, AIR
PROVING SWITCH ON PREPURGE SYSTEMS (SEE WIRING HOOKUPS.)
REPLACE S89.
CHECK SPARK
IGNITION CIRCUIT.
SEE COMPONENT
CHECKS.
NO
SPARK OKAY?
YES
• MAKE SURE IGNITION CABLE
– PROVIDES ELECTRICAL CONTINUITY.
– DOES NOT TOUCH ANY METAL SURFACES.
– CONNECTIONS ARE METAL SURFACES.
– SHOWS NO SIGNS OF MELTING OR BUCKLING.
REPLACE AND SHIELD CABLE IF NECESSARY.
• MAKE SUE BURNER SPARK IGNITER AND S89 GROUND
(BURNER) TERMINAL HAVE EFFECTIVE COMMON
GROUND. POOR OR ERRATC GROUND WILL CAUSE
NUISANCE SHUTDOWNS.
• CHECK FOR CRACKED INSULATOR ON IGNITER OR
FLAME SENSOR. REPLACE DEVICE WITH CRACKED
INSULATOR TO PREVENT SHORT TO GROUND.
NOTE: IF S89 LOCKS OUT, RESET BEFORE CONTINUING.
• CHECK FOR 24 VAC ACROSS VALVE AND VALVE (GROUND)
TERMINALS ON S89. IF NO VOLTAGE, REPLACE S89.
• MAKE SURE IGNITER AND SENSOR ARE PROPERLY
POSITIONED. SEE COMPONENT CHECKS.
• CHECK ELECTRICAL CONNECTIONS BETWEEN S89 AND
GAS CONTROL. IF OKAY, REPLACE GAS CONTROL.
REPLACE S89.
NOTE: IF S89 LOCKS OUT, RESET BEFORE CONTINUING.
• MAKE SURE FLAME CURRENT IS AT LEAST 0.8 MICRO AMPS.
SEE COMPONENT CHECKS.
• MAKE SURE L1 AND L2 ARE CONNECTED TO THE PROPER TERMINALS.
• MAKE SURE FLAME DOES NOT TOUCH SENSOR INSULATOR AND
THAT SENSOR INSULATOR IS BELOW FLAME. EXCESSIVE HEAT
(OVER 1000 F [538 C]) WILL CAUSE SHORT TO GROUND.
RELOCATE SENSOR OR SHIELD INSULATOR IF EXCESS HEAT
IS SUSPECTED.
• IF CHECKS ARE OKAY, REPLACE S89 MODULE.
• CHECK FOR PROPER TEMPERATURE CONTROLLER OPERATION.
• REMOVE VALVE LEAD AT S89: IF VALVE CLOSES, RECHECK
TERMPERATURE CONTROLLER AND WIRING; IF NOT , REPLACE GAS
CONTROL.
REPEAT PROCEDURE UNTIL TROUBLE FREE OPERATION IS OBTAINED.
Fig. 5. Troubleshooting S89E,F.
9
• CHECK FOR 120V TO SPARK GENERATOR.
• REPLACE SPARK GENERATOR IF VOLTAGE OK.
• IF NO VOLTAGE, REPLACE S89.
M19839A
68-0066—4
Advertisement
