The sound can occur whether hot water is flowing out of a faucet or going down a drain.
Intermittent noise in attic after outside spigot turned on.
It happens when water which is incompressible stops suddenly and has no place to go.
An outdoor faucet that makes a loud vibrating noise when it s turned on or off probably has a worn out faucet washer.
First turn off the water to the faucet.
What s most likely causing the problem depends on when you hear the knocking sound.
It would get louder as more power was being used.
Frustrated by the loud knocking noises coming from your pipes.
If banging is caused by air in the pipes the noise will mostly occur right when you first turn on a faucet.
If you re still stumped i would turn off the house s water and check for visible water damage throughout the home and look for water pooling in the yard around the outside of the house or in.
While cold water is running.
It usually occurs at one of these 4 times.
Install water hammer arrestors.
Open your faucets to drain all of the water from your plumbing system.
A drain piping leak inside of a building cavity can also produce a noise that is hard to track down.
Both of these issues can occur for several reasons so you may need a professional to evaluate and address the problem.
While hot water is running somewhere in the house.
In faucets something as simple as a slack washer or untightened screw at the base of the faucet can result in high pitched screeching due to the tremors.
Draining the water system to get water out of the vertical air chambers or installing water hammer arrestors can solve this problem.
You can easily replace it without removing the entire outdoor water faucet.
Alternatively if the water pressure is higher than what the pipes are used to the same shrill sound can occur.
Supply pipe leaks may be continuous and thus are eventually discovered by water stains or mold or intermittent such as a leak around a tub or shower control that drips into the wall cavity only when the valve is turned on.
The incoming water will flush the air out of the pipes but not out of the vertical air chamber where the air supply has been restored.
Turn off the water supply to your house at the main supply or street level.
You may also notice sputtering as the air bubble travels.
We had a buzzing sound in the winter that turned out to be the electric meter.
Installing insulation and anchor strapping around the pipe within the wall can usually fix the problem.
Turn the water back on.
