knocking/banging pipes

[acrabat]

Hello all I know most regulars here will be bored to death with questions like this but despite a search I cannot find any questions/ answers to fit my problem. There is a banging/knocking noise coming from my hot and cold pipes when absolutely nothing is turned on. It has been going on now for a couple of months. It happens randomly and I cannot re-create it by turning anything on or off. I was fitting a new bathroom suite and towel radiator recently so had the supply turned off at the main stopcock and had the CH (combi) drained but the noise was still there. I just can't work this one out. Normally I would blame the neighbours (semi detatched) but the noise sure sounds like it's coming from my pipes. Any suggestions welcome TIA

[david lang]

Only experience I've had in this area was a bathroom tap. I fitted a pressure regulator and a section of flexible pipe. Don't know which one cured it, but it stopped.

I've installed a number of high pressure water pipe lines and as standard we would put in a 1 metre flexible every 50 metres or so to avoid water hammer - these were 200bar @ 30 litres/min.

Dave

[EricP]

"Kettling" in your boiler by it overheating.

Your water supply is shared with your neighbours closely and the water bounce from bad plumbing in their side is coming into your house and setting your plumbing off.

Or you have a "primatic" copper water tank and it is venting itself a lot for some reason. (This makes one hell of a racket)

[Ian Stirling]

That's one hell of a shower.

[Owain]

It's what you need if you're running two combis

Owain

[david lang]

:-)

Just the sort of pressure washer you need to clean up after growing mushrooms or beansprouts commercially.

Dave