Lochinvar Electric Water Heater

**DIYNOT** · 01-17-2011, 11:04 AM

Just noticed as I walked by my water heater water running down the side. There is a valve (?) on top with a hose thread that has dripped. Is this the PRV? It appears to have stopped dripping now, should I worry and call a plumber or watch it a while. To my knowledge there has been no work done on water lines in the area (though two homes are being built on the street, so it is possible). I keep the water temp way low...one notch above lowest setting. Have had no problems with hot water in the house.
Any advice is greatly appreciated...I know very little about plumbing! Thanks!
btw: water heater is 5 years old..house built in '05.

**jadnashua** · 01-17-2011, 01:03 PM

A WH (normaly) doesn't have a PRV...that, if installed, is in-line somewhere just after the home's main shutoff. If the valve has a lever on the top, it is probably the T&P safety valve. That can release water under two conditions (unless defective): if the internal pressure exceeds its limit, or the internal temperature exceeds its limit. Unless the thermostat has failed, and the water is exceptionally hot, it is more likely pressure. If your home uses a closed system (it has a check valve in it so house water can't push back to the street), it should have an expansion tank to moderate the water pressure when it expands due to heating it. First thing I'd do is get a screw-on water pressure gauge with a tattle-tale hand (peak holding indicator). They cost about $10. Leave it installed for 24-hours and see what the peak pressure is. If that's normal (stays below 80psi), and the temperature of the water at the WH isn't excessively hot, the valve probably needs to be replaced.

**DIYNOT** · 01-17-2011, 01:52 PM

Thank you! Yes it does have a lever attached to the top.
I will get the gauge and check the pressure; I have not noticed the water being excessively hot.
Just checked again and it is not leaking anymore...been about 3 hours now.

**jadnashua** · 01-17-2011, 05:27 PM

It is normal for pressure to vary during the day. If the pressure is within normal range, then the T&P valve needs to be replaced...

hj · 01-18-2011, 07:30 AM

Some people use the term PRV for both "pressure relief valve", (instead of T&P relief valve), and/or "pressure regulating valve". The T&P valve should not have a hose thread on it, and should have a discharge pipe on it which at least runs down close to the floor. We have to take your word for it, that the water on the side of the tank actually came from the T&P valve.

**ballvalve** · 01-18-2011, 09:55 AM

Yes, its a ongoing problem. PR can be relief or regulation. PRV has the same problem.

T&P should be used, or just relief valve. And Regulator alone is a safe phrase.