We have a Rheem 50 gal. water heater, installed in Oct. 2008. The temperature is set at 120 degrees and yet, the temperature of the hot water, whether in the shower, bathtub, or sinks, varies from day to day. Some days it is very hot; other days tepid.

Would this be a gas or electric heater?

the temperature of the hot water, whether in the shower, bathtub, or sinks, varies from day to day
Does this affect the entire house or just the master bath?
Is the cold water warmer then usual?
Did this condition just start? Any plumbing or faucet changes lately?
Back to you, Tom

Tom: Thank you for the reply.
ALL sinks, tubs, showers are affected. The condition has been ongoing since day one. We just really never paid much attention to it. There have been NO faucet changes lately. It is a GAS heater. Do you think the thermostat might be defective? THANKS


I have spoken to Rheem Tech support. They have instructed me in taking water temperature at the heater. I will do so and advise them of the findings.

Please keep us informed o anything new.

The condition has been ongoing since day one.
I'm beginning to wonder if this isn't a cross connection between hot and cold either in a one handled faucet or when the water pipes were first installed, Regards, Tom

When I said "day one"... I meant since the installation in 2008 of the new water heater... NOT since we've moved into our home (in 1967). I spoke with Rheem and I'm about to test the thermostat. I'll keep you informed. THANKS!

Who installed water heater? Real question is, was any soldering done near the cold water input connection?

When I said "day one"... I meant since the installation in 2008 of the new water heater Thanks for setting that straight. Were heat trap nipples, (see image) installed on the heater connections? If so, replace them with 3/4" brass nipples. Let us know what Rheem has to say. Cheers, Tom