Dometic WH shuts off after 5 mins

[James D]

2020 airstream flying cloud 25 front bedroom. Dometic/atwood 93755 dual gas electric 6 gallon. Dewinterized a few days ago and ran all systems. All looked good. Fired up the gas/electric water heater checked a few minutes later, water was good and Hot called it good. Check it again today and both electric heating element and or gas burner shut off after five minutes and only come on again if I turn the gas/ electric switchon again, then only stay on again for 5 mins. Yes, bypass is in correct position. Water pump running fine. No blown fuse or tripped breaker. No air trapped- ran at least 6 gallons trying to troubleshoot. Thermocoupler looks good took it off, cleaned ends and replaced. Thermostat(s) or circuit board? Something else?

Appreciate it.

[TitusNW]

I don't have your water heater but looking at the manual it seems you should contact Dometic and get instructions on how to troubleshoot the ECO Switch and Thermal-Cutoff Switch both shown on page 7.


The manual also has a discussion of the ECO switch on the top of page 4.


Steve

[James D]

The thermocouple looked good. Took it off, cleaned leads and reinstalled. I assume the filament would have been broken if it activated. I went to check thermostat leads and one broke off :-(. Trailer is at the shop now.

[James D]

Ended up being the mixing valve.