Atwood water heater question.

[000]

Hi all,
I have an Atwood water heater in my camper. When I know the heater is full of water I flick the switch and the unit fires up fine after about 20-30 min lots of hot water.
The issue is its not shutting off. The only way it will shut off is flick the switch again. When I do that it shuts off fine.

Is there away to test the thermostat? Anything else I can check?

Thanks

[000]

LP only sorry thought I had that in there!!

[skipnchar]

Is this when operating on LP mode or Electric mode?