I've been seeing some strange water pressure in my house, nothing has changed recently. I had always seen the pressure coming out hard at first, after the water heater had been running, but the pressure seems higher lately. I found a leak behind the fridge that I think was caused by the high pressure, ruined part of the floor in my kitchen.
City water comes in at about 90 psi, there is a pressure reducing valve that reduces it to about 40.
Hot water temperature was about 130F
I just replaced the expansion tank with another 2.1 gallon expansion tank, it was precharged to 40 psi, I double checked it and left it there. Doesn't seem to be anything wrong with the old tank, it was only at 10psi once removed, but it still holds air.
Now, with the new tank on, I still see bouts of high pressure. I clocked it at 100psi this afternoon. 100 seems very high to me, I've never noticed it that high in the past.
Do I need a bigger tank? Just odd that this started out of the blue..
Best Answer
Either your PRV is bad, your gauge is incorrect or being used incorrectly, or the end points in question are old and just in need of repair as these things happen (and if all installed at the same time it is not unheard of that they fail around the same time).
It does not make sense that your water heater is a culprit nor the expansion tank.