Noisy Water Pipes.

[DIYSpectator1]

We are getting sporadic banging / tapping noises from our pipes which occurs about every 15 minutes even when there is no water running or our central heating on or even being recently on.
The problem started when we had a new kitchen fitted and the sink was moved. Plastic piping was put in place of old copper piping so we've been told that this new piping isn't the cause of our problem. The noise gets quieter, but more regular when we lower the pressure by reducing the flow from the stop tap.
At the same time we seem to have developed a much louder hammering noise when we turn our taps on and off, although I'm not sure if this is related. I can cope with this hammering noise, but the sporadic banging is driving us to despair and our plumber doesn't seem to be able to figure it out. Any thoughts?

 

[Nige F]

New ballvalve in roof storage tank...if there is one ...and a Pressure reducing valve on incoming water main..for a reasonable £ starter And check run/clipping of added/replaced plastic pipes. Also an obscure one If soil pipe is plastic and runs through roof ..check it`s not binding at 1st. floor and ceiling level. It might just have been moved slightly if the kitchen fitters plugged in a new waste pipe to it. Hope this helps your plumber

 

[DIYSpectator1]

Thanks for your reply. Don't have a storage heater so can't be this. He did put a link to the waste pipe so can check that out, although not sure why this would make a difference depending on how open the stop tap is.
We do have a pipe that was capped off and doesn't go anywhere - I saw on a previous post that this could cause problems. Going to try and fasten some of the pipes down better in a hope that this could help as I don't fancy reducing the water pressure coming in as it's just at the right setting.

 

[DIYSpectator1]

Got another plumber in and he explained that the pressure regulator wouldn't leave us with lower pressure water, just a more stable flow. However, shouldn't need this as the water hammer was because we had turned the stop tap down to reduce the sporadic noises which occurred even when we weren't using water. The water hammering noise went as soon as he turned the stop tap back open to full.
The sporadic noises we believe were coming from a dead end pipe that hadn't been correctly fastened down. So far so good - no noises (touch wood).

 

[RigidRaider]

Curiously my own experience is exactly the same as yours - if I leave the main stopcock only partly open we get all kinds of seemingly random water hammer sounds from our pipework; so much so that I even came on this forum a few weeks ago to ask if it was possible we were hearing our neighbours.

Turn the stopcock on fully and we get blissful silence. Don't ask me why.