Try pulling the check/release lever on the pressure release valve a couple of times.
Sometimes, foreign chit gets under the seat just like what happens with a carburetor of an engine.
Do be advised the wadder comes out of the drain line quickly, like a cow pissin' on a flat rock.:biggrin2:

I was thinking the same thing George, I went yesterday and flipped it back and forth a few times. I put a bucket under the drain and checked it today and didn't see any water. Hopefully that's all it was!

What is the temperature set to?

I haven't touched the temp settings so it's the factory 120F. I checked the water coming out of the faucet and it's around 110F so I guess that's right. The TPR valve is supposed to trip at 150PSI or 210F.

Ok I got my hands on a pressure gauge. Connected to my outside spigot, it jumped up to 120PSI when I first turned it on then dropped to 70PSI and stayed there. I'm begining to think this TPR valve is indeed defective...

Normal residential pressure is 40-60 PSIG.

The just replaced all the water and sewer lines in my neighborhood and I've noticed the pressure has felt higher than before, maybe that's why it's 70PSI. But the city code says a pressure overflow tank is only need if it exceeds 80PSI.

Regardless, the TPR valve is only supposed to open if it exceeds 150PSI so something is definitely wrong...

Do you have a regulator? I had to add a regulator also. Mine would leak after someone took a shower, while it was heating the water back up.

After leaving the pressure gauge on the spigot for a few hours I'm seeing the pressure is all over the place. As high as 160PSI and as low as 60PSI. I called the water company and they just said any pressure adjustments are customer side, so I guess I'm getting a pressure regulator. Those come preset for 40PSI...

Yes, sounds like you need a PRV and I bet they put a check valve at the street so you probably need a expansion tank too.

These people are pretty good to deal with.

https://www.supplyhouse.com/Pressure...alves-17082000

https://www.supplyhouse.com/Expansion-Tanks-14860000