Hello All,

I'm super stumped with a problem I've been having with my plumbing for some time. The house is 11 years old (purchased new), and is city fed. I've been hearing the noise for several months now, but only now has it become worrisome (it was very faint and hardly ever happened in the beginning).

Essentially, when opening or closing any faucet (hot or cold) in the house I hear considerable banging from my pipes. In some faucets (second floor baths) I can even feel a knock from the handle of the faucet when the banging occurs. The noise seems to be loudest just a bit away from a shower/bathtub in the second floor bath, I believe the banging can be felt in the floor as well. I've done the following so far;

  1. Made sure all pipes were tight and secure.
  2. Replaced the cartridge assembly for both showers.
  3. Replaced the seats for the lavatory faucets.
  4. Drained and refilled the pipes... a few times. (Hoping to fill the air chambers with air again).

I'm familiar with the principle of water hammer, and I see how it occurs when suddenly stopping the flow of water. But I can't seem to figure out why the pipes would bang when opening the faucet as well. I've opened up the drywall below the tub and can't feel the pipes banging against the joists, so I believe the noise is caused by the water in the pipes themselves. Usually, you will hear 3-4 bangs, almost seems like water is flowing back and forth hitting something.

Since the problem occurs when opening/closing both the hot and cold water, I decided to try one last thing... turn off the supply to the hot water tank. Strangely enough, the banging no longer occurs... What could cause this?