A.O. Smith BTR 118 SERIES, Service Handbook, Page: 16 / 31

15
Servicing should only be performed by a Qualified Service Technician
GENERAL SERVICE CHART
Condition Cause Solution
DAMPER OPENS NO POWER
TO IID MODULE • DAMPER NOT FULLY OPEN • REPLACE DAMPER.
• DEFECTIVE PROTECTOR
SWITCH
• REPLACE PC BOARD.
PILOT LIGHTS, SPARKS
CONTINUOUSLY
PILOT FLAME NOT PROVING SEE FLAME RECTIFICATION - STEP
8.
HEATER WILL NOT IGNITE NOT PROVING PILOT FLAME
EXISTENCE
INTERRUPT 120 VAC POWER.
• CHECK GROUND WIRE
ATTACHMENT.
• CLEAN OR REPLACE PILOT
ASSEMBLY.
PILOT GAS NOT COMPLETELY
INTERRUPTED AT END OF
HEATING CYCLE
• CHECK SUPPLY GAS
PRESSURE.
• REPLACE GAS VALVE.
WEEPING TEMPERATURE
AND PRESSURE RELIEF VALVE • THERMAL EXPANSION ADD THERMAL EXPANSION TANK.
• FAULTY VALVE REPLACE RELIEF VALVE.
LARGE VOLUME WATER
RELIEF FROM T&P VALVE • EXCESSIVE WATER
•
TEMPERATURE
CHECK WIRING REPLACE DUAL
CONTROLLER.
• FAULTY RELIEF VALVE REPLACE RELIEF VALVE.
PREMATURE TANK
LEAKAGE CONDENSATION • INCREASE STORED WATER
TEMPERATURE AND
CONFIRM PROPERLY SIZED
APPLICATION.
CONTAMINATED AIR • REMOVE CONTAMINANTS.
• SUPPLY CLEAN COMBUSTION
AIR.
WATER HAMMER • ADD WATER HAMMER
ARRESTOR.
• REDUCE WATER PRESSURE.
•
REMOVE UNNECESSARY
CHECK VALVES.
THERMAL EXPANSION ADD THERMAL EXPANSION TANK.
DEPLETED ANODES SCHEDULE ANODE CHECKS -
REPLACE AS NEEDED.
DAMPER WILL NOT OPEN BINDING SHAFT SUPPORT VENTING
DAMPER MOTOR • REPLACE DAMPER.
NO SPARK AT PILOT -
DAMPER FULLY OPEN DAMPER ASSEMBLY SEE STEP 7. Services Switch may
bypass problem until replacement
part is received.
REPLACE DAMPER .
IID MODULE REPLACE IID STEP 6.
SPARK CABLE REPLACE CABLE STEP 7.