Hot Water Heater, wierd issue.

[Shannonjd78]

2020 Momentum 29G

I'm having a problem with my electric hot water heater. I have checked and/or replaced the thermostats, fuses, control board, and heating element with no results.

The symptoms are that when the 120V from the hot water heater relay is disconnected I read 120v on the relay pin. When I connect the 120v line back to the heating element it temporarily turns on then in roughly 20 seconds I hear another relay behind the breaker panel click and power is lost at the element. If I wait another 20 seconds it clicks back on then off again, over and over.

All other systems onboard work, including the gas options for the fridge, water heater and regular heat.

I did read online that the ground and neutral are not supposed to be common on the rv. When not on shore power they are not connected but when I plug the rv in to shore power or a generator they read common.

This is really my only confusion as the heating elements neutral wire, if tied to ground may show a short even if the power is running through a 10 ohm load (heating element). Additionally, the power will never turn on to the water heater if I have the front ac running but it cycles if I have the back ac running.

Please help if you have any solutions.

 

[Soundsailor]

Hey, it looks like you're new here, welcome to the forum. From what you've said, it does sound like a ground issue. Has it always been this way? Could you have a frayed wire somewhere?

 

[Shannonjd78]

Thanks for the welcome. I've only had the Camper for a month now, got it used. I've checked everything that is easily accessed, nothing visible. But if it is an internal ground issue, the ground and neutral should read common, that's not the case, it's only when plugged in with power on.

 

[Shannonjd78]

Hey, it looks like you're new here, welcome to the forum. From what you've said, it does sound like a ground issue. Has it always been this way? Could you have a frayed wire somewhere?

I just realized that the front ac will not turn on unless the hot water heater breaker is on.

 

[mbarry1834]

I found wiring burned on my relay because of a poor crimp or loose on blade at the flag terminals.
Relay was located on left side of waterheater and not easily accessable. The image below is not my relay but very similar. I had to replace the ac wire from the relay to the rocker switch on the WH.
Relay https://www.amazon.com/dp/B092M3FFT5?ref=ppx_yo2ov_dt_b_fed_asin_title
Crimper https://www.amazon.com/dp/B0BPY7HW5H?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1