Any plumbers out there???? In my 5 year old townhouse I occasionally hearing a humming/vibration noise coming from the unfinished basement where the main water line comes into the house through the basement floor.
This only happens when we turned on a faucet, any faucet in the house, or the shower and sometimes when the toilet flushes. Mainly when faucet water is running. As soon as the water is turned off the sound goes away.
I live in a townhouse with sprinkler system. There is a pressure reducing valve installed after the main shutoff but sprinkler system is branched off before the PRV. Any ideas of what this could be or what to start looking for or checking?