Originally Posted by Old-Biscuit
Would be helpful if you could post Brand/Model of that on demand heater
It is an Atwood Od-5001.
After more trouble shooting. I noticed the high temp switch was bypassed for some reason, but with a poor wiring job. I mad a splicer with end crimps and trouble shot again after testing 12v voltage through the system. I had my 7 year old in the trailer helping turn the shower on to see if the unit would fire.
When he turned the cold water off and the hot was running for a second before he turned it off the unit fired up. I got him to turn only hot on and it fired up. It appears from what I think, the system needs a incoming regulator as the city water may be to much and when the cold is on it is over pressuring the hot side and not allowing it to flow to some sort. For not i have adjusted the temp to allow for full hot on showers so we can rinse off and i purchased a regulator to see if that will solve the issue, I'll need it anyways. Will update next week on staus when it comes in.