Major Water Hammer dilemma

[Bowsaint]

I live in a new build one bedroom flat, built October 2011, and recently we have started noticing a sequence of banging noises after turning off the taps in our flat.

I called Pimlico Plumbers and whilst the plumber was very helpful, the upshot of an expensive call-out was a new water pressure fitting which has only very slightly helped the water hammer. The advice I have been given - which makes sense based on where the banging noise is emanating from - is that there is a loose pipe clipping behind our bathroom suite and tiles.

Clearly this cannot be fixed until tiling is taken out, replaced and even that will only fix one clipping (of course there could be loose clippings elsewhere that later emerge).If there multiple loose clippings then clearly large parts of our ceiling need taking up.

Similarly to most new builds, our water pipes are plastic

Does anyone have any advice? My worry is that there seems to be a very simple solution, but that this solution could cost multiple thousands of pounds to fix.

All help, suggestions and advice would be greatly appreciated.

 

[Newboy]

In my experience, water hammer within plastic pipework is rare.

Are you sure that all your pipework is plastic?

Does the problem occur with all taps?
Are the taps that trigger the problem 1/4 turn type?


Was a pressure reducing valve fitted?

I'd be looking to fit a shock arrestor on the affected pipework before I started to destroy the flat.

Another 'fix' might be to change the type of tap

 

[Bowsaint]

Thanks newboy for such a quick and helpful response.

Yes I am sure the pipe work is plastic.

With regards the taps, all three of our taps (bath, kitchen and bathroom sink) cause the issue, though more so with the bathroom basin. The bathroom basin is 1/4 turn, the others are I think called mono mixers (up and down levers).

A pressure reducing valve and 1 x non return valve was fitted though whilst this seemed to help initially, a day later the problem is no different really.

Does this shed any light? Thanks again.

 

[jeff the gasman]

If you know where the loose pipe is more or less, you could make a small hole in the vicinity and inject some expanding foam. Let it set before using the taps and it will grab the pipe.
It's a long shot but could work.
Jeff

 

[Newboy]

Does the water hammer affect hot or cold or both?

Any idea what the pressure reducing valve has been set too?

 

[gigz]

If its recently just started, have you turned the stop tap off for any reason recently ? If you have, try adjusting it by small amounts to stop the hammer.

 

[St0rmer66]

Mini expansion vessel or 'shock arrestor' will sort it. Pressure reducing valve wasn't a bad idea but both are sometimes needed (I have both on my house with 5bar standing pressure and that's not even considered a "huge" pressure in the first place!).

 

[Bowsaint]

Just to confirm newboy that the water hammer affects both and hot and cold.

St0rmer66 thanks for your message. Would a mini expansion vessel or shock arrestor make any difference if a loose pipe clipping was causing the water hammer?

Thanks.

 

[St0rmer66]

Just to confirm newboy that the water hammer affects both and hot and cold.

St0rmer66 thanks for your message. Would a mini expansion vessel or shock arrestor make any difference if a loose pipe clipping was causing the water hammer?

Thanks.

I'm not so convinced that it even is a loose pipe. With fully secured pipes you can still have water hammer. In either case though, if you have a mini expansion vessel taking up the hammer the loose pipe would then stay, if not completely, mostly still and therefore quiet.

 

[buck51]

Water hammer is a very broad description, that can cover many problems.

When does it start?
how long does it go on for?
Can you stop it and if so how do you stop it?

Is one big Clunk or does the pipes vibrate for a period of time?

 

[onlyfitidealboilers]

Some times water hammer can be caused by the jumper in a stop tap on the cold mains inlet. This will effect all taps,other causes are pipe work not supported correctly yams sagging / waiving around.

If it only happens on hot water on " all hot taps"it could be the ballcock on the
Domestic tank in the loft.

If it only happens when you flush the loo it's likely to be the ball cock in the bog.

If it only happens on a certain tap it's likely the washer requires replacing.

Troll threw that and am sure you will find answer. Mini expansion vessel on cold mains after the non return valve is perfect.