Water heater intermittent leak

[pharpe]

Hi. I have a 40 gallon gas water heater that was installed in 11/1999. Yesterday is started to leak. My roommate noticed water coming from the bottom and the front right leg at the base of the unit. He turned off the water and gas to the hot water heater and the leak stopped.

This morning I turned the water back on and was unable to get it to leak again. I re-lit the burner and got it back to temp to see if that was related but still cannot get it to leak.

I have inspected the bottom of the unit inside where the burner is and there are no signs that it is corroded through there. I also looked at the top and do not see any dripping from the pipes. I have read that the pressure relief valve may be faulty and cause leaks but it is connected to a pipe that runs under the house. Could it be that the relief value is leaking directly at the valve its self and running back down to the jacket? Any suggestions on the best wat to trouble shoot?

[Terry]

The tank is eleven years old.
It may be time for replacement.
What you are inspecting is the outer metal covering, not the tank.
In between the two, is insulation.
The PRV is piped to a drain, or to the outside. It wouldn't be leaking on the floor from the tank.
I like Bradford White and Rheem tanks.

[hj]

You HAD a pinhole leak in the heater. When you turned the water off you relieved the pressure so the leak stopped. THEN it rusted over to seal the leak before you turned it back on. I have taken water heaters apart and the tanks would look like they were shot with a "rust machine gun" because there were so many places where they had rusted and sealed themselves. EVENTUALLY, one of those spots will rust out again and this time it will be too large to seal itself and you will have a floor. Replace the heater before you reach that point.

[pharpe]

The PRV is piped outside. When I pulled the test lever on the PRV I got water coming out of the top of valve where the pin goes in. That water runs back down onto the top of the unit, into the outer jacket of the HWH and then comes out of the bottom. I think that might have been the problem. I've had issues with plumbing presser before so it may have just been releasing excess pressure but leaking out of the top of valve and not through the overflow pipes. Going to replace the PRV and watch it for further leaks.