My water heater started overflowing. I have a Rheem residential water heater that is 8 years old. Water is coming out of the top of the unit from a round thing (sorry to use such technical terms ;) ) that is under a little. This started after (or perhaps during) my dishwasher running. I turned off the water at the top of the tank and that stopped the water from coming out. I tried turning it back on while running a hot tap, and that didn't stop the water from bubbling over (almost like a really weak drinking fountain.) It was cold/room temp when I found it and that did not change. Any ideas about what is wrong or how to fix it? Thanks in advance!

You failed to mention gas or electric. 8-10 years is typical lifetime for a water heater, so you should consider replacement.

That thing is a Temperature and Pressure relief valve. Sometimes they can be reset, other times they cannot.

If this is an electric heater and the thermostat failed, the PRV should open.

If it is gas and the gas valve failed to shut off, then the PRV will open. In case of gas the regulator would have to be replaced since they are not repairable.

Thanks for the help! Yep, it's gas... I've got a plumber called so hopefully I can get it fixed ASAP. Thank you again! :)

Is it the brass thingy (gotta stick with fancy terms) that then runs down the side ot the tank? That is the T&P and it eother went off for a reason, temp or pressure, or it just failed itself. What is the warranty on that particular tank, if its 8-10 years I'd install a whole new tank and get it over with.

Bob is right your heater is old and it is time for replacement, but you can still try to replace the T&P valve, it is cheap and easy to replace, see the images below, if you need help how to replace come back to us and we will help you,Thank.

John

I hate to keep beating this dead horse, because I think the answer I get will be the same as above... replace. :) But it is not coming from the brass thing (T&P from the picture posted), but from a circle right in the center of the top of the water heater, that has a little vent cap over it. There is a blue ring that is the same color as the top of the water heater, then inside that there is a dark gray metal ring that rises above the blue one by about 1/2 an inch or so. It looks similar to the burner on my gas stove if I take the little metal cap off. Here is a picture of it with the water coming out between the blue and gray rings:

Attachment 22617

Yep, replace, the actual tank is ruptured and not repairable,

I agree with Ballengerb1 (Bob) your water heater is gone time to be replaced, good Luck.

John

Thank you everyone! I really appreciate the time you took to answer my questions, and for the great information.

Are you going to replace it yourself or hire a pro?

I'm hiring a pro. When it comes to gas I am pretty aware of my limitations. Just about anything else I will try myself. The last thing I need is to blow up my entire townhouse building by screwing it up. :)

OK, good luck, I know what you mean.