AC water heater

[DaveBunker]

Over the mild Sierra winter up here in Pioneer, CA, drained my fresh water tank, opened up water lines to make sure no water remained to possibly freeze (didn’t get cold enough) and left my water heater on to keep the remaining water warm. Snap disc heater kept the water bay nice and warm when temps were hi 20s at night. I even kept the living room temp at 50 degrees. Felt the water heater from time to time and it was warm to the touch. All good.

So I’m leaving on Monday to a camping destination, filled the fresh water tank and checked water flow from both water pump and house hook up. All good. Shore power water heater switch has remained on for several months lite red. So I bled the air out of the lines, turned on the hot water faucet and no hot water. Water heater is cold. Checked plug, reset circuit breaker, turned the switch off for 30 minutes then back on. Still water heater is not coming on. I can’t check the propane side cause I’m currently out of propane, but will do when I arrive at camp sight.

If anybody has any suggestions, please enlighten me. Is it possible it just needs to be reset? Switch is currently in the off position. Did I accidentally do something to the heating element over the last couple months? I assumed the water heater had water in it. Maybe I assumed wrong.

[Chris M.]

A water heater left on can evaporate the water in the tank over time. Its possible the element was over heated and burned out. Lp Side uses same controls. If the lp is working when you get gas, you will probably need a new element. With the rv plugged in and 110v water heater switch on check for power, with a meter, at the element. if you have 110v ac the the element is bad.

[Old-Biscuit]

Which Brand/Model


If Atwood GC10A-3E
AC is separate system
AC from circuit breaker to OEM Switch/set of t-stats/element (backside of WH Tank)





If Atwood GC10A-4E
Uses DC to control both AC & LP functions
*Common DC to Switches to circuit bd (WHITE/Electric & ORANGE/LP)
*DC to 'thermal fuse & T-stat (Brown Wire) then from T-stat to circuit bd (BROWN Wire)----Opens/140*F and Closes/110*F for heating cycles

*DC to ECO/Gas Valve via RED Wire (Full 12VDC/LP & just a few millivolts when on Electric so ECO is in control loop (Opens/180*F and triggers FAULT Light/lock-out heating cycles ---Closes at 150*F but have to Reset Circuit Bd by turning on/off switch off then back on)
*DC to DC/AC Relay via YELLOW Wire to trigger AC to Element (Backside of WH Tank under Black Cover)---AC wires from Relay can fail and Element will short if DRY Fired
*AC from Circuit Breaker to DC/AC Relay then to element
Got to have DC in order to have AC PLUS AC to element


GC10A-4E Wiring











So get out your Voltmeter and follow the AC (3E Version)
OR
follow the DC & AC (4E version)

[DaveBunker]

will check all circuits. Pic shows the model

[DaveBunker]

Well there’s 110v at the heating element terminals at the back side of the WH. So I assume I burned out the AC he’s.ting element.

[DaveBunker]

[ATTACH]237450hi hard is it to change the element if I found one. Obviously the tank needs to be empty, right?

[DaveBunker]

Is there a way to bypass AC element on this unit and use propane until I get a new element

[RockyMtnRide]

Originally Posted by DaveBunker

Is there a way to bypass AC element on this unit and use propane until I get a new element

You can run it on propane only if the element is fried

[DaveBunker]

Or since I believe the AC heating element is fried, will the propane work as normal when fired up?

[RockyMtnRide]

Originally Posted by DaveBunker

Or since I believe the AC heating element is fried, will the propane work as normal when fired up?

It should. On my Atwood both the 12 volt signal to control the element and the propane go through the control board and a single thermostat controls when each or both turn on and off. The element 12 volt signal from the control board energizes the relay that is under the cover back at the element. The 120 that drives the element goes through this relays contact. There is not any feedback to the control board that detects the health of the element. Behind my heater is a dedicated outlet for the water heater. If i unplugged the 120 volt power source for the element the relay would still energize but no 120 so no element. Heater still works on propane.

[DaveBunker]

That’s the answer I was looking for. Thank you so much for your input. The camping trip will move forward.

[Old-Biscuit]

Propane WILL function if Electric Element is burnt out.
Just leave AC Circuit Breaker OFF
Leave Electric Switch OFF....no need to energize the DC circuit for the Electric functions
Especially when R/R element


Need a 1 1/2" thin walled socket to R/R element.
It screws in/out and has a gasket for sealing

Tank does have to be empty ...element is submerged in water


Continuity test will confirm element is bad
Turn AC Circuit Breaker OFF
Remove Wires from element.
With Voltmeter test continuity between the 2 terminals on element....NO Continuity/Element bad
With Voltmeter test continuity between White Wire Terminal on element and the element flange----Continuity/element is shorted


Standard 120V 1400W screw in element...available at hardware/big box stores
Element Wrench also available

[DaveBunker]

Thanks old-biscuit, very much help. I will head out on the trip and fix it when I get there, if the parts arrive on Monday. I found the correct part on Amazon with the wrench.

[AnotherMike]

Originally Posted by Old-Biscuit

Need a 1 1/2" thin walled socket to R/R element.
It screws in/out and has a gasket for sealing

Originally Posted by Old-Biscuit

Standard 120V 1400W screw in element...available at hardware/big box stores
Element Wrench also available

Replace the gasket even if it looks good.
Been there helping a friend, done that, new element didn't come with a gasket. We thought that the old one could be reused. WRONG.

One of my projects down the road is to take my 6 gallon Atwood propane-only water heater and add the parts to make it a propane-120vAC electric unit. Yes, I know there is a Camco kit for that, but I'd rather use factory parts.

Then another project is to add the mixing valve that blends cold with the hot to hit a specific temperature... with that in line you can crank the heater temperature up and you have the effectiveness of a 15 gallon heater.

All of this can be done with Atwood stock parts.