A.O. Smith 120 trough 500 - Manual (Page 20)

BTR TANK TYPE HEATERS
SERVICE HANDBOOK
A.O. Smith Water Products Service Handbook
Irving, Texas ©2000 Training Department
19
TROUBLESHOOTING BTR WATER HEATERS
To troubleshoot a BTR water heater check that:
• 120 VAC is supplied to the heater
• the tank is full of water
• gas is supplied to the unit
STEP 1 TEST THE TRANSFORMER
STEP 1 - TO TEST THE TRANSFORMER - Using a multimeter, test for 24 VAC
between the secondary transformer terminals.
IF THEN
The meter does not read 24 VAC: • Check that the 120 VAC is supplied
from the On/Off Switch – if not, replace
switch.
• Check that the 120 VAC is supplied
from transformer.
The meter reads 24 VAC: • Go to step 2.