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Noah Klein
Noah Klein,
Category: HVAC
Satisfied Customers: 23
Experience:  Owner, Master Plumber at Royal Plumbing, LLC
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My hot water tank has a Rheem SP13845A Gas Thermostat that

Customer Question

My hot water tank has a Rheem SP13845A Gas Thermostat that seems to stop working. If I unplug it and plug it back in again it will heat the water but then it will stop again.
Submitted: 2 years ago.
Category: HVAC
Expert:  Noah Klein replied 2 years ago.

You almost certainly need a replacement gas valve or a combustion safety valve. Your issue sounds like the combustion safety valve is tripping when the heater gets hot. Alternatively, there could be an issue with the gas control valve. In my experience, the gas control valve is open the culprit after the thermocouple. Your unit is electric start. The gas control valve is easy to replace and costs about $165 on

Expert:  Noah Klein replied 2 years ago.

BTW - I am not even sure your unit has a combustion safety valve. GE says it does, but I don't see it anywhere on the parts breakdown. Possibly they just print that in all the manuals.

Customer: replied 2 years ago.
Thank you for your information. I will order one and have it replaced.
Expert:  Noah Klein replied 2 years ago.

You can probably do this job yourself. It is very easy and doesn't take more than 20 minutes. When you get the part, we can have a video chat ($25) and I can walk you through it.