ATWOOD WATER HEATER WON'T SHUT OFF

My last campers water heater didn't have a mixing valve and it shut off at around 120F. My Airstream's Attwood does have a mixing valve on the water heater outlet I think it runs up to around 180F before it shuts off. I'm told the idea is a 6 gallon water heater with a mixing valve that heats the water hotter will give you the equivalent supply of a much larger water heater.

Check the water temp with a thermometer. "Water got really hot" is not very specific. RV water heaters get significantly hotter than the water heater in your home.

A 6 gallon tank will take about 30 minutes to heat up a tank full. A little longer would not be surprising.

While the burner is lit, try pulling one of the wires off the propane valve.

If the burner continues to run, the valve is sticking - and defective.

Verify the two thermostats are in physical contact with the water tank so they can measure the actual temperature.

Probably would help if you posted the model # of the water heater.

Start by verifing wiring. Could be ECO and thermostat wires are backward.