Pressure valve leaking on HWH

[Tinkee]

Just had a little plumbing work done under the house to replace old galvenized pipes with CPVC. The plumbers had to tie in to some lines that are fairly close to the line that runs in to and leaves my HWH. Now it seems that after my wife and I shower at night and use hot water that the pressure relief valve will start getting a steady drip. Once I open the valve and let a little water run its fine the rest of the night. Im a little worried since this is the pressure valve. Not really a big fan of having my house explode =p I tried turning down the temp on the HWH but maybe I need to cut it down some more? The HWH heater is brand new. Was purchased in february of this year by the previous owner of the house and hasnt been used until we moved in. I actually hadnt noticed any real problems until after the plumbing work was done.

[HayZee518]

a t&p valve is preset at the factory to open at 195 degrees. pulling the valve and letting it reset itself is usually a long time fix. it has a rubber seal.

[Redwood]

Take a look at these linked articles...

The T&P Valve on my Water Heater is Leaking

Thermal Expansion Tanks For Water Heaters

To me it sounds like a "Thermal Expansion" issue but further trouble shooting is required to be certain. If it is thermal expansion resetting nor replacing the T&P valve will resolve the dripping...

[Tinkee]

Thanks for the quick reply! Those articles were very helpful. So if its a thermal expansion issue just replacing the valve wouldnt fix my problem right? I tried to turn down the thermostat to see if that would stop my problem. The water in the house still seems pretty hot though so Im not sure if I had a thermostat problem or not. So at this point what would you suggest I try? Should I somehow test the temp of my water to see if its around 120F? Or should I test the pressure to see if its 80PSI ( I think I can do that at the ballcock at the bottom of the tank right?) Or should I just buy a thermal expansion tank and hope that fixes the problem? Thanks again for the help!

[HayZee518]

they ain't that expensive and it is a safety device, yeah go buy another one.

[Redwood]

A Lazy Hand Pressure Gauge costs $10-15 and is available at many hardware stores and home centers...

I like to have reasonable certainty that what I am throwing my customers money at fixes the problems or, is at least a component in the problem.

Being in the trade if you charged money to replace a T&P valve and the leaking continued showing a Thermal Expansion Tank was needed the customer usually feels that what they paid for the T&P Valve replacement should cover it...

Too many of those calls and you end up broke and hungry after working all week...

[HayZee518]

Hey dude - we're talking about a hot water tank that doesn't use an expansion tank! read the post!

[Redwood]

Hey dude - we're talking about a hot water tank that doesn't use an expansion tank! read the post!

Correct!

And as we should know the T&P Valve can open for multiple reasons.
Excessive Temperature, Excessive Pressure, or Defect...

Excessive Temperature could be caused by several problems in the water heater such as a bad thermostat, stacking, shorted elements, and possibly other things...

Excessive Pressure could be caused by excessive supply pressure non-regulated, a failed pressure reducing valve, and in a "Closed" system thermal expansion.

If you like to throw parts and labor at problems thats fine...
I prefer to troubleshoot, find the problem and fix it!
It tends to provide better quality service to my customers...
Kay Doooode!

[Redwood]

The Reply I gave was an example.

I wouldn't want to throw an expansion tank at a failed Pressure Reducing Valve or, Defective T&P either...

In most cases when things aren't working properly there are a number of diagnostic steps that can be gone through to determine the cause(s) of a problem.

What I'm saying is it is best to follow those steps and do it right the first time...
HayZee there really is no need to jump on anyone...
Just my $0.02....