Water heater relief valve dripping

[Michael24]

I have a brand new water heater and occasionally it drips from the pressure valve. I have the temp set on 120 and it won’t go any lower.

 

[Reach4]

Typically this means that you don't have a working thermal expansion tank, and you need one.

You can look at your water pressure with a pressure gauge, and you probably will see that it currently rises to 150 psi after a hot shower, and you stop using water.

 

[Sponsor]

 

[Dj2]

Do you have a pressure reducing valve (PRV) on your main line?

 

[Terry]

Have you checked your water pressure? You can pick up a gauge like this in the irrigation department at a hardware store and thread it to the drain at the bottom of the water heater. The T&P valve is set to release at 150 PSI.
The max pressure a home is supposed to have is 80 PSI. If you're within pressure, then it may be something wrong with the T&P valve.