Faucet Makes a Loud Noise When We Turn it Off. Why?

Our kitchen faucet is making a loud noise when we turn it off. What’s the issue?

Plumbing noises can be very irritating. There could be a couple of things causing these loud sounds. Your noisy faucet could be due to what is called water hammer. Water hammer can occur when you turn off the water at a faucet or an appliance rather quickly. As water flows through pipes and the valve is shut off quickly, it causes the water to stop abruptly in the pipes. If the pipe is near wood, it will bang against it.

There are a few possible reasons you are hearing these water hammer noises:
Loose pipes. If you have loose pipes in your walls, anchor them with metal or plastic clips to limit movement.

Damaged air chambers. These lengths of pipe, installed behind fixtures like your faucet, hold air that cushions the shock when flowing water is shut off quickly. If these air chambers get filled with water, they will not work properly.

It is also possible that your water pressure is too high. If it is over 80 psi, you may have a problem. There are water pressure test gauges you can get to test the pressure yourself, or you can hire a professional plumber like Roto-Rooter to test the pressure for you and make necessary adjustments to reduce your home’s water pressure to a more appropriate level.

Sometimes faucets making whistling or squealing sounds. It’s possible your noisy faucet is due to a washer that is either the wrong size or is not held securely to the stem. Adjusting the washer or replacing it should eliminate the noise. If you do this repair yourself, remember to turn off the water supply to the sink before starting the job.

Additionally, if you live in an older home with iron or galvanized water supply pipes, it’s possible your pipes have scale buildup. The remedy for severe buildup is to replace old water supply pipes. Extensive plumbing repairs of this type should only be done by a licensed professional plumber.