leaking temp/relief valve

[Redwood]

The guys here should have told you that you had a leaking T&P, not a over pressure issue when you opened other taps and it continued to leak.

He didnt have a leak previously, and no one changed his plumbing, and a PRO installed the heater WITHOUT a ex. tank, so Sherlock would go direct to the valve seat.

Hopefully you didnt waste your money on a expansion tank.

And I'll bet if he opened and closed the 'defective' T&P several times, it would have seated and stopped leaking anyway.

Maybe if he didn't have the installing plumber coming back out we would have gotten into the diagnostics....

Your wisdom or, lack thereof never ceases to amaze me...

[ballvalve]

I am amazed at your lack of ability to diagnose a problem when all the needed information is before you.

He needed to change his T&P valve FIRST, before all of the typical backyard mechanics "lets change and add parts and see if we fix the problem" but with the added stupidity of not starting with the actual LEAKING part.

"Hey! the T&P drips after 10 years - lets add a expansion tank to fix it!!"

Calling an average plumber is akin to heading to a root canal without novacaine. And the odds of a true repair are about like slot machine win rates.
I'll give Terry an exception.

Someone might have mentioned that his valve piping also need to be re-routed to a drain or outdoors, and not to his wooden floor.

The valve should only open under three situations: you manually open it, the pressure is too high, the temperature is too high. ANY other reason means it should be replaced. I'd double-check the expansion tank, it could be shot, allowing the pressure to rise. The tank should essentially be full of air. If it thumps like it is full of water, it is probably shot.

This guy got it right. NOT a plumber.

Get a drop of wisdom and read the entire thread before shooting from the hip.

[Terry]

The T&P is the first thing replaced. Especially if it had been fine originally.

If the water meter had been changed out to a check valve version, then an expansion tank would be needed.
I've seen some homes where the street pressure was 120 PSI.
With those homes, I add a pressure reducing valve on the incoming cold.

[RoadKing99]

While he was here fixing flange on my toilet he also swapped out the T&P. So far so good and no drips over the past few hours. Said he ends up changing the T&P quite frequently on the B&W heaters he installs for a Watts one. He checked the expansion tank first and added a little air to it to get it to 55 psi I think.

I just picked up a J horn with a check valve in it from the town water department. I'm going to have him replace the original j horn that has been giving me some leaking problems off and on for the past 6 years or so where they attach to my copper pipes. Plus this will have a ball valve rather than the crummy spigot type that never really killed the main completely anyways and seemed to leak a bit. Just the shock of the water being turned off and on can make it leak at the connections. Thank God for mineral deposits I guess

If you find a good plumber you trust and does good work they are worth their weight and gold and nine times out of 10 they do better work and are less expensive than the guys a box store will send out....never again!

[Gary Swart]

You really should have zero water coming out of the T/P. I'd suggest you flush it some more, but if it continues to seep, get a new valve. They are cheap and easy to change.

[RoadKing99]

No drips at all a week later...looks like the T?P was the culprit on a year old heater...other that this thing is money