Originally Posted by srpuywa
OK thanks all - looks like I will be labeling those switches
Is there a CB for the electrical side?
As previously noted, the switch with the lightning bolt operates the 120v electric heating element, and the one with the flame operates the gas burner, and the red light indicates a failure (gas mode). Both switches are 12v
circuits to the circuit board on the front of the water heater. One of the 12v
fuses in the fuse panel provides power to the board, switches and gas solenoid valve. There is a 120v circuit breaker that provides power to the electric heating element through a junction box on the rear of most late model water heaters. A relay on the passes the 120v to the element.
Pulling the 12v
fuse will effectively disable the water heater, but 120v will be present in there should you go poking around. Switching the circuit breaker off will disable the 120v operation, but if the fuse is in place, normal gas operation is available.
This was probably an involved answer to a simple question.