: I just installed a new Moen faucet in my bathroom; all the same pipes, etc., just a new faucet. Suddenly, whenever I turn off either cold or hot, there is a single clang or thud coming from the pipes.
: It isn't loud, and the pipes don't visibly vibrate, but it wasn't there with the old faucet, and I'm wondering what it is, whether it's harmful, and how I can rid myself of it!

: Many thanks,

: Jim Martin

Jim,
It's water hammer.
It can be harmfull, it depends on how much hammer and how tough you pipe and fittings are.
It is mainly annoying.
Water hammer arresters can be added to help reduce the hammer.

• Water hammer info