I have a very odd issue that I can't solve, perhaps someone here could help. The pipe attached to my main shutoff valve is emitting a soft knocking sound at around 120 beats per minute. The sound persists as long as there is any amount of pressure, and I can feel it in the pipe nearby as well as in the valve handle itself. The weird part is that if I turn on any hot water tap, the noise vanishes. I'm a new homeowner so I don't have much experience, so any help would be appreciated. What I've checked so far:
Drained the system completely and refilled
Turned the water off overnight and checked toilets for leaks
I don't feel the pulse at the water meter line
Turning hot water on anywhere in the house stops the noise.
Thanks in advance!
PRV? Not sure what that is or where i would find it
Pressure reducing valve. Typically found directly after the water meter to reduce high municipal water pressure to reasonable residential water pressures.