Electric water heater trips breaker even when switched off

When we connect to shore power the circuit breaker for the 110V water heater trips immediately, even with the switch on the inside switch panel turned off. When I turn this switch on (circuit breaker still tripped), the LED in the switch illuminates (although rather dimly), but it does go off completely when the switch is turned off. I had read that some newer trailers have just 12V connected to the switch in the panel and then a relay to actually switch 110 to the heater. I've tried removing the switch panel but can only get it out far enough that I can see no relay here, maybe it's mounted somewhere else? I've been searching through the various threads and user guides for wiring details but haven't found any reference to a relay for the water heater. We are still within warranty but miles from any dealers (Bridgeport, CA) so I am hoping with a little more information I can get this fixed myself. Thanks, Jim
 

danemayer

Well-known member
Re: Electric water heater trips breaker even when swithced off

Hi Westernwagon,

If you have a relay, for it to be tripping the 110V breaker when the switch is off, I think there'd have to be a dead short across the 110V side of the relay. If the relay was ok, even if something was wrong further downstream, there would be no power getting past the relay and no breaker trip.

If your switch is passing the 110V directly, the same thing would apply. A properly working switch that's off wouldn't pass power to a shorted component downstream. So the problem would be a short at or in the switch.

But these possibilities seem unlikely to me. I'd start with the power pedestal you're plugged into, and the cords or adapters in use. Especially if the problem just showed up when plugged into a new power source. A voltmeter and a non-contact voltage tester would be good tools to help with this.
 

wdk450

Well-known member
Re: Electric water heater trips breaker even when swithced off

I am wondering if this is a weird symptom having to do with the heater element pitting and passing current through the water to the grounded tank. I know it should not happen if the RV wiring is correctly done, but humor me by:
1) Removing all AC power sources from the trailer.
2) Take off the water heater outside cover, remove the 2 screws on the plastic water heater element cover (bottom center), and remove the cover.
3) Unscrewing both the black and white wires from the heater element. Position the ends in the air not touching metal or each other.
4) Temporarily re-connect AC power to the rig.
5) See if your circuit breaker symptoms re-occur. If they do not, the problem is probably a bad water heater element, along with possible miswiring. If you don not feel confident checking this out, get professional help. Remove all power again and put all connections/covers back the way they were.

BTW, I just went through a similar scenario with my water heater for about 2 months. (Kept blowing the breaker when I turned the red AC switch on - Problem evidently was a short where the water heater is connected to the RV wiring in a metal box on the top frontward side of the heater, on the inside.) I just ran the water heater on propane during that time until I fixed it.
 

mobilcastle

Well-known member
Re: Electric water heater trips breaker even when swithced off

I am wondering if this is a weird symptom having to do with the heater element pitting and passing current through the water to the grounded tank. I know it should not happen if the RV wiring is correctly done, but humor me by:
1) Removing all AC power sources from the trailer.
2) Take off the water heater outside cover, remove the 2 screws on the plastic water heater element cover (bottom center), and remove the cover.
3) Unscrewing both the black and white wires from the heater element. Position the ends in the air not touching metal or each other.
4) Temporarily re-connect AC power to the rig.
5) See if your circuit breaker symptoms re-occur. If they do not, the problem is probably a bad water heater element, along with possible miswiring. If you don not feel confident checking this out, get professional help. Remove all power again and put all connections/covers back the way they were.

BTW, I just went through a similar scenario with my water heater for about 2 months. (Kept blowing the breaker when I turned the red AC switch on - Problem evidently was a short where the water heater is connected to the RV wiring in a metal box on the top frontward side of the heater, on the inside.) I just ran the water heater on propane during that time until I fixed it.
X2-wire in junction box was fried-check that out.
 
Re: Electric water heater trips breaker even when swithced off

Thanks for the comments Bill, It'll be tomorrow before I get time to do the tests. However, what I see behind the water heater cover seems to be a little different from the troubleshooting guide and the manual that came with the trailer. I don't see any reset buttons or secondary 110V switch, however I assume the heating element is still behind the white cover at bottom center. BTW the model number on the label at far right is GC10A-4E and I think it is an Atwood model although the manuals that came with the trailer are for Suburban. I did try to insert a photo of what it looks like but either I'm doing it wrong or it's very slow to upload.
 

danemayer

Well-known member
The troubleshooting guide is based on Suburban, but Atwoods are similar in operation. I don't think Atwoods have the secondary switch. They should have the other components however.

Once again, if the water heater has no power from the switch, it's hard to see how anything at the water heater could trip the breaker, unless there were two failures.


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FIXED !! So the Atwood has it's electric element and 110V connections on the back in a junction box. Upon opening the box I was greeted with melted twist nuts and insulation. The hot wire nut had completely melted and the ground wire insulation was burned through (thank goodness for circuit breakers). Tidied it all up and now is all OK. As a side note the Atwood does use a relay to switch the 110V, it is inside the same junction box. The DW is now very happy. Thanks for your help guys.
 

danemayer

Well-known member
As a side note the Atwood does use a relay to switch the 110V, it is inside the same junction box.
Thanks for circling back around with what you found. Now I understand why the breaker tripped with the switch in the off position. The Atwood junction box has the unswitched hot 110V wire from the circuit breaker. I believe the Suburban has switched power coming into its junction box; with switch off, there's no power in the box.
 

ParkIt

Well-known member
Thanks for circling back around with what you found. Now I understand why the breaker tripped with the switch in the off position. The Atwood junction box has the unswitched hot 110V wire from the circuit breaker. I believe the Suburban has switched power coming into its junction box; with switch off, there's no power in the box.
Yep. The Suburban has no power in the box which made it easier to troubleshoot than the Atwood.
 
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