Page 1 of 1

banging in pipes

Posted: Wed Feb 13, 2008 11:35 pm
by gravy
Any advice would be very much appreciated.

In a basement flat after increasing the water pressure (opening up the stop cock). When the washing machine stops or any tap is turned off there is a terrible noise in the pipes. Like a banging noise.

When the pressure is turned down the noise stops. However I need the increased pressure for the shower and taps.I know other flats in the block have their stopcocks fully open.

I read somewhere that the jumpers in the stopcock could be worn, and causing the problem.
Is it a case of having the stopcock changed or can the stopcock be serviced.

I also read that in some cases air chambers are needed around washing machines and dishwashers. knowing nothing about air chambers or plumbing could you advise if this is a big job or if the air chambers can be fitted anywhere else.

The local plumbers merchant said that there could also be air in the system and may need to be bled. I dont understand this as I would of thought the increased pressure would blow the air out.

I have checked that all the fittings are good and no pipes seem loose.

Could you please advise the cheapest and easiest solution.

Many thanks gravy

Posted: Thu Feb 14, 2008 1:01 pm
by uk_ducati
hi
does the banging happen when the washing maching stops filling up? if so what you are getting is what is called water hammer. this happends sometimes when you have a lot pressure to a tap or outlet and the flow of water suddenly stops, eg turning the tap off fast. dont know the physics behind it, just know it happens.
a simple way of cureing it in your situation would be to fit a pressure relief valve just before the outlet to the washing machine and offending taps. this way you will keep the required pressure to the shower.

hope this helps

paul

banging pipes

Posted: Sat Feb 16, 2008 11:30 am
by Gareth Thomas
Could be as simple as your pipr runs (under the floor) are not clipped adequately or even at all. Pull up a floorboard and have a look. If there's no clips holding the pipes to the loists this could well be your problem

Pipe Banging

Posted: Sat Feb 16, 2008 11:23 pm
by jedums
Don't dismiss any help given, but I would also check that your header tank is not overflowing or near overflowing. The washer in the valve piston can cause water hammer or if it's a PLASTIC valve it uses a large diaphram washer and when it is worn gives off a noisy and scary high pitched whine.

If it occurs when water from your header tank is used (toilet, Hot water etc.) is used then open up a tap from the same source until ithe sound stops, and gradually slow the flow to stop. Replace tank washer.
Good luck.

Posted: Mon Feb 18, 2008 3:51 pm
by gel
[quote="uk_ducati"]hi
does the banging happen when the washing maching stops filling up? if so what you are getting is what is called water hammer. this happends sometimes when you have a lot pressure to a tap or outlet and the flow of water suddenly stops, eg turning the tap off fast. dont know the physics behind it, just know it happens.
a simple way of cureing it in your situation would be to fit a pressure relief [b]valve[/b] just before the outlet to the washing machine and offending taps. this way you will keep the required pressure to the shower.

hope this helps

paul[/quote]
What is a pressure relief valve
Are they expensive
gel

re water hammer

Posted: Fri Feb 29, 2008 11:27 am
by gravy
Thank you all so much for your great advice.

Fitted a pressure relief valve and problem solved.

Many thanks again.

Wishing all health and happiness.

cheers gravy

banging pipes

Posted: Fri Feb 29, 2008 2:26 pm
by gel
Hello
I tried all the suggestions mentioned in the forum except fitting a pressure relief valve.
I had checked that the pipes were securely anchored , that washers were all in good condition ect Then I tried an idea from outside the forum.
That is to create an air pocket some where in the pipe work system.
Presumably the water pressure is dissipated in compressing air similar to an air cushion rather than trying to compress water.
It worked instantly and has been OK for the last 7 days
I created an air pocket by draining a length of the pipe work with an additional valve fitted and then closing valve so that water could not enter when the water was turned on again
It sounds complicated but was very easy to do.
If any one wants futher info please make contact through the forum.
Cheers
gel