Atwood Water Heater DSI Fault

Before you assume the board is bad again I would go to the Attwood web site they have a nice trouble shooting section there and they show how to check the board and other components. You have a new system, is your board a potted board or a regular board where you can see the soldered components. On the later you can remove it and look for burned components or tracks. As I said in my first post I never heard of this before, but if you have replaced 5 or so EOC and TSTATS it sounds to me like something must have been wrong from day one, because it sounds like you have replaced an ave of two per year since you got the MH assuming you bought this new. Old Biscuit is very knowledgable and has helped me in the past and may be he can explain AC ripple better, but I would check the power wire I believe it is brown and see what the voltage is on that wire. Just logically thinking to short out these items the voltage or current would have to spike very high.