On the Atwood you have a high-temp cutoff inline. (In between your brown wires. One end plugs into the board and the other end of plugs into the cutoff. Take the cutoff out of line and connect the brown wire from the cutoff directly to the circuit board. If that solves the problem then you just need a new cut off. This happened to me and stopped water heater from working on gas or electric. I went to a camper store and they had them (2 in a blister pak)at $26. Also for Atwood parts check Amazon. Price on there for a circuit board was about $80 cheaper than the dealer. Amazon lister was a certified Atwood dealer. Good Luck.