Originally Posted by ArmyAV8R
5Picker, thank you. So if I pull either wire from the right hand 12V propane side and the flame goes out, itís likely the board.
So then Iíd pull the heater out and be able to reach the board on the tank...?
Thanks for the pics. As 5picker suggested, i would try to start it up on propane, then pull one of the red wires to the thermostat assembly. If the propane then goes off ( which is the same as the thermostat(s) properly opening and cutting power to the board), then I would spend my time looking at the thermostat assembly/mounting.
If the flame does NOT go off, then there would seem be some kind of secondary 12 volt power getting to the board.
The way the thermostat assembly works is the bottom one opens when the tank/water gets to 130 degrees. The top hi-limit thermostat would stay closed. Once the water tank/temp drops low enough, then the bottom thermostat closes, thus turning back on power to the board...up until it all reaches 130 degrees again.
However should the tank/water get to (IIRC) 165 degrees then the hi-limit/ECO opens shutting off power to the board.
This ECO(Emergency Cut Off)/hi-limit thermostat is a backup safety should the bottom thermostat fail, and keeps you from getting too scalded should the bottom one fail. If the ECO trips, it has to be manually reset, which is that button on top. The bottom and top thermostats are connected via that small thin fusible link you see between them. This will burn out like a fuse, and protects the wiring.
If you water heater is not cutting off at 130 degrees then it should at 165. If both thermostats are faulty (which is kinda weird) that would cause that. It's also why I'm wondering if there is a mounting problem and the sensors on the backs of the thermostats are not correct.