A.O. Smith 120 trough 500, Service Handbook

Page: 44 / 55

BTR TANK TYPE HEATERS
SERVICE WORKBOOK
A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department
43
GENERAL SERVICE CHART
CONDITION CAUSE SOLUTION
DAMPER OPENS NO POWER
TO IID MODULE
. DAMPER NOT FULLY OPEN
. DEFECTIVE PROTECTOR
SWITCH
.EFFIKAL – REPLACE DAMPER CONTROL
ASSEMBLY
. REPLACE DAMPER
. REPLACE PC BOARD
PILOT LIGHTS, SPARKS
CONTINUOUSLY
PILOT FLAME NOT PROVING SEE FLAME RECTIFICATION - STEP 16
HEATER WILL NOT IGNITE
NOT PROVING PILOT
FLAME EXISTANCE
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
. THERMAL EXPANSION ADD THERMAL EXPANSION TANK
WEEPING TEMPERATURE
AND
PRESSURE RELIEF VALVE
. FAULTY VALVE REPLACE RELIEF VALVE
. EXCESSIVE WATER
TEMPERATURE . CHECK WIRING
. REPLACE DUAL CONTROLLER LARGE VOLUME WATER
RELIEF FROM T&P VALVE
. 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
SHAFT SPRING WEAK/BROKEN REPLACE DAMPER NON-EFFIKALS
DAMPER MOTOR REPLACE MOTOR EFFIKAL-REPLACE DAMPER
CONTROL ASSEMBLY
NO SPARK AT PILOT -
DAMPER FULLY OPEN DAMPER ASSEMBLY REPLACE PC BOARD - SEE STEP 10
Services Switch may bypass problem until
replacement part is received. (EFFIKAL –
REPLACE DAMPER CONTROL ASSEMBLY
IID MODULE REPLACE IID STEP 12
SPARK CABLE REPLACE CABLE STEP 13