Knocking sound in cold water supply All aspects of plumbing questions and answers, help, tips and information

[rynso]

Hi,

Our cold water system has started knocking when taps etc are turned on and off. There is a noise like the pipe is being hit with a rubber hammer, but it is difficult to locate exactly where the noise comes from.

Any ideas of the cause and suggested solutions please?

rynso

[htg engineer]

'There is a noise like the pipe is being hit with a rubber hammer'

It's called water hammer, caused by water coming to a sudden halt (closing a tap) causes the pipework to vibrate. This can be rectified by supporting pipework (clips) if any pipes are touching each other/floorboards/pipe boxing etc, clip and lag/insulate pieps

Firstly though, try closing the mains stop tap slightly.

Or if none of the above work, you could fit a water hammer arrester.


htg

[rynso]

[quote="htg engineer"]'There is a noise like the pipe is being hit with a rubber hammer'

It's called water hammer, caused by water coming to a sudden halt (closing a tap) causes the pipework to vibrate. This can be rectified by supporting pipework (clips) if any pipes are touching each other/floorboards/pipe boxing etc, clip and lag/insulate pieps

Firstly though, try closing the mains stop tap slightly.

Or if none of the above work, you could fit a water hammer arrester.


htg[/quote]

Many thanks.

rynso