A.O. Smith 120 trough 500 - Manual (Page 36)

BTR TANK TYPE HEATERS
SERVICE HANDBOOK
A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department
35
STEP 14A PILOT VALVE - OHM TEST
BTR 120 – 400 GAS VALVE
STEP 14A. PILOT VALVE - OHM TEST. If pilot assembly is sparking but no pilot flame
is established, disconnect the pilot valve solenoid leads. Using a multimeter, (set to read
ohms) test for 20* ohms resistance +/- 5 through the solenoid coil.
IF THEN
The meter dose not read 20 ohms plus or
minus 5: • Replace gas valve
The meter does read 20 ohms plus or
minus 5: • Gas valve should work. Also check that
pilot gas is present and pilot tube or
orifice are not blocked