Unexplained Noise
#1

Arrived home last week to hear a constant pure tone like sound coming out of heat/air conditioning ducts on first floor of townhouse. Unit next to mine had recent concrete repairs (lots of jackhammering!. Noise seems to be coming from water supply line into house. Plumber who fixed leak in that line removed "pressure control valve," saying it wasen't necessary in my town about 5 years ago. Noise is constant and unchanging. Who (other than ghostbusters) should I call - or better is there anything a real novice can do?
#2

Take a pressure gauge and test the pressure at a hose bibb, if it's 80lbs or above, get the plumber back to reinstall the pressure reducing valve.
This could be your problem.
Best Regards Plumber2000
www.atozplumbing.com
This could be your problem.
Best Regards Plumber2000
www.atozplumbing.com