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!

  • @Jakor
    1•1 year ago

    I’m not an expert, but it sounds like your pipe is hitting a resonant/natural frequency. If this is the case, your best shot is to change that natural frequency.

    Best thing I can think of to do that is to add a pipe support somewhere where the noise is occurring (likely where you have a long unsupported run of pipe). Look into a rubber-cushioned pipe clamp.