Noisy plumbing.

Ed M
by Ed M
Recently, our upstairs bathroom sink hot water faucet/plumbing makes repeated rapid noises when turned on. Not everytime. First thought it was water hammering, but it is not a loud banging noise. May be air in the water line, but I can't figure how air got into the line and why has it just started? Bathroom was renovated three years ago and these noises started about two weeks ago. Any ideas? Thanks and Merry Christmas.
  4 answers
  • One reason is water hammer vibration. When the faucet is turned on the seal that opens and closes begins to vibrate. This rapid movement opening and closing makes for some real strange noise. That is one of the reasons for the noise. Another reason can be the pipes expanding due to changes in the water temps as hot water runs through them. If the pipe fasteners within the wall have come loose the pipe can be rubbing on the interior of the wall causing a vibration of sorts. This is a common issue. Air has nothing to do with it. Air acts as a cushion taking up movement as its compressed. That is how water hammer resistors work. An air bladder is placed in the pipe which takes up the movement when a faucet is turned off quickly as you would find in a dish washer or a washing machine.
  • KMS Woodworks KMS Woodworks on Dec 24, 2012
    If you can imagine a Kazoo, where a membrane vibrates as air is blown over it, you may have a similar phenomenon going on here...but instead of air it is the water flowing over the valve parts. sometimes "rebuilding" the valve corrects this as some of the sealing components may be worn to a point that they allow movement. I have seen that simply coating some of them with plumbers grease helps in some cases.
  • Ed M Ed M on Dec 26, 2012
    Thanks to all for your analyses and recommendations. Will try one or all in hopes of resolving my situation. Merry Christmas and Happy New Year!!
  • Ed M Ed M on Dec 30, 2012
    Recently I had turned water valves off and then turned them back on slightly. After this posting I turned the problem line valve off then opened it wider....no problems since. Thanks again for your posts.