Atwood water heater in a 2019 bullet 248rks

[skids]

We bought the trailer late fall. I winterized it. My wife flipped the toggle switch that turned on the electric water heater. She thought it was for electricity for other things. More that 45 minutes elapsed, so I kind of figured the HW heater element was fried. Wouldn’t you know it, it is under the corner with a small opening and stuffed way in the back. The element is behind a black box and has an electric cord plugged into an outlet. So I figured I could simply unplug the plug from the outlet and test continuity for the 10.2 ohms. WRONG!

I spent a couple of hours taking the damn thing apart, and finally tested the element to find out it was fine (!!!!). So then it dawned on me to take a better look in that black plastic connector box. Yes, I think there is a relay in there. I should have looked for a relay from the start because the toggle switch was undoubtedly 12 volt, and the element was 120 volt. So... I put the old element back in and buttoned it all back together.

1. Everything I have read says there is an off/on switch near the circuit board. I can not find it on mine. Did they do away with it since the breaker box is close by?
2. Even with the wall toggle switch in the off position, the romex to the outlet box is HOT so keep this in mind if working on a similar configuration.
3. Apparently the yellow wire into the junction box on the tank is what triggers the relay to turn on the heating element. It apparently comes from the circuit board outside. For future, because it is so tight in there, I would really like to know if I can more easily put 12 volts into the yellow wire (from the circuit board clip outside (to close the relay), so that I can check continuity (for 10.2 ohms) on the male plug in that tight space...

[skids]

OK, I put the trouble shooting technique to the test for the water heater element.
1. Unplug shore power.
2. Switch on the toggle on the wall for the electric water heater with 12 volt battery engaged. This closes the relay switch to the element in the black box.
3. Unplug the cord from the socket.
4. Test for ohms across the two male spades of the plug the leads to the water tank.
5. Ohms should be something like 10.8 ohms for a 1400 watt element.

EAZY PEAZY!

[LHaven]

Originally Posted by skids

1. Everything I have read says there is an off/on switch near the circuit board. I can not find it on mine. Did they do away with it since the breaker box is close by?

Doubtful, since the heater manufacturer has no way of knowing where your breaker box will be.

The switch is typically in the lower left corner, and is operationally reversed (on is down). On my 2019 rig, it was cleverly camouflaged by being covered with a piece of white metallic tape that exactly matched the interior of the compartment, and I didn't find it for weeks.

[skids]

I'll take a harder look. Thanks.