Water heater question
Control panel has 2 water heater switches. One switch is 120v and the other is labeled 12v. I’m not imagining the water heater being able to operate on 12v. Is that really off the battery or code for switching to propane?
Forum Discussion
5 Replies
- From photos it appears you have a Atwood 10 gal Combo water heater
The 12V on/off switch is for the PROPANE
The 120V on/off switch is for the ELECTRIC Element
12V DC is used for BOTH heating sources.
The 120V AC is triggered by a DC Relay .....located on backside of WH Tank where element is (Under protective cover)
12V DC is control voltage for circuit board, t-stat/ECO, propane gas valve
The LED above the 12V switch is a 'FAULT LIGHT'
Propane fails to light off AND PROVE it lit....fault light comes on
ECO (Hi Temp T-stat) OPENS (electric or propane being used)...fault light comes on
LED ON the switches........indicates switch is ON
Wiring for Atwood Combo water heater - OlBuiscuit will be along to tell us, but I would venture a guess that the AC circuit is a simple t-stat with a relay. The 12VDC circuit includes an igniter, a gas solenoid, some kind of thermocouple ignition verification, with an LED fault indicator, or in short, much more complicated controls, best done with DC.
- Agree. Propane uses a 12 vdc solenoid.
Although it is likely the one labeled 120 vac is also a 12 vdc switch the energizes a 12 vdc interposing relay to send 120 vac to the heating element. - ^^^^^^^That would be my guess.
- Propane, with 12v controls.
