Water Heater

[Igezl]

Hello, I am new to this sight. I have an Atwood on demand water heater OD 50 in my TT and it wont fire up. I replaced the Spark Control board and Thermostate and still wont start. I jumped wires from Thermostate and it did start, ran heater for 5min and turnd off. Any thought as to why it wont run. Any help would be appreciated.
Thank you,
Pete

[MrMark52]

Do you have the manual for the unit?

I did find it - if the heater worked when you jumpered the heating thermostat then it sounds like that stat has a problem. All subsequent power to the controls come through that stat.

It came on and ran for 5 minutes then shut off is probably because the high limit stat was satisfied the water in the heat exchanger had reached temperature. I suspect if you had turned the hot water on, the burner would have reignited.

[Old-Biscuit]

Won't fire up unless there is a demand...faucet open/flowing water at at least 0.5 gpm (1.0 - 1.25 gpm is best)

ECO...HI Temp T-stat has to be manually reset (push button in) if it trips

Modulating Valve...set to middle range between MAX & MIN