Bad pressure regulator?

[dabensys]

Hello all,

My relief valve on my water heater tripped open earlier today and now leaks intermittantly. I took my pressure guage and checked the pressure at my front (upstream of the PR) and back (downstream of the PR) and got 140PSI and 105PSI, respectively.

The PR is rate for 25-75 PSI so I ASSume the PR is bad, or going bad, but it still seems to be reducing the pressure. So my questions are:

1. Should I call my county to report the 140PSI incoming pressure?
2. Should I call a plumber to replace the PR?

The water is already turned off to the house.

Thanks!

PS: Last year I posted many questions about a major bathroom remodel where I changed the entire layout. Thanks to all of your patience and good advice I am happy to say that the county signed off on the CO last week! Thanks!

[Gary Swart]

More likely you need a thermal expansion tank. Heated water expands and has to go somewhere. If you have no PRV, the expansion is absorbed by the water main. A PRV has a check valve that prevents that. The resulting pressure reaches the limits of your T/P and it opens as it is supposed to do.

[hj]

You need to check the upstream pressure while a faucet is running, and shortly afterwards. If the pressure stays constant you need to adjust the pressure regulator, if it is low with the faucet running and then starts to increase afterwards, repair or replace the regulator.