Suburban SW6D

[Lowemow]

Hey Guys,
A newbie here but not to RVing. Got a head scratcher, at least to me. My water heater is the 2nd one in a 2010 24ft Komfort. It is not used anymore other than being used as a swimming pool change room or an overnighter for friends. The hot water is started up every once and a while and has been fine till now. Startup is fine and runs for 15 or 20 mins and shuts down. I thought I had sourced it out once I realized the high limit switch was cutting out. If I waited over night it would restart. I installed a new one, same issue. Changed out the electronic board ....same thing. Cleaned off the direct light prongs ( there is no thermocouple or pilot light) Made sure the rear shower was turned off at the handles. No luck. Any ideas?? They would be much appreciated.

[Lowemow]

Problem solved. The middle shutoff valve was in open position (the winterization position) and should have been in the closed position. DUH !!!!

[Lowemow]

Maybe I didn't explain properly. It has always taken 30 to 40 mins to heat up this 6 gallon tank from start. When I run the water after the premature shut down it runs hot for maybe 15 seconds then turns cold. That is not normal. Thought there was an air bubble and emptied the tank but it changed nothing. I have run the system with 110 degrees temps outside and yes it takes less time maybe but always over 1/2 hour. Plus after it shuts down the inside switch will not light it up until the next day and by that time the water in the tank is basically cold.

[bucky]

It's 75 degrees in Vegas right now at 2 AM your time and will be in the 90s later today. When the water is hot enough it shuts off. They are not designed to run continually.