Water Hammer - Banging sound from taps when Shutting the taps off?

mazibee

Hi All ,

Hopefully someone can help me out.

We moved in our new home in Sept 2019, and replaced the System boiler with the new Worcester Style 8000 Combi,

Our building person/ plumber  was managing our few renovations projects for us before we moved in September 2019.

During the winter season  Dec-19 Feb 20, when we started the heating , water dripping sounds can be heard, once the radiators are hot the noise stops (looks like water is leaking and dropping from the pipes)  I kept on eye on the boiler pressure and it was not dropped for the whole year, but t he noises like rattling of the pipes, water dripping were there.

Few months back kitchen sink mixer tap was leaking  ( multi turn two hole) and got it replaced by Quarter turn and from that day a sound is coming when ever we close any tap,

We have the following that are making the banging noise

Mixer tap in kitchen sink (

Mixer Tap in Bathroom sink single for (hot / cold let side its hot and when completely right its cold

Mixer in bath tub multi turn

Toilet Cistern making a a noise after its been filled.

My plumber has installed one  Water hammer arrestor 0.16 under the Kitchen sink near the stop valve and it has stopped that banging noise when off the cold water in the Kitchen sink.

I opened all the taps hot and cold one by one, closed them to check and the banging noise is still there.

If I put

One more water arrestor under kitchen sink on the hot line

Two water arrestor under the bathroom sink

Two water arrestor under the bath tub

One water arrestor on the filling pint in the toilet cistern

Will it help solving t he problem as its driving me crazy

I will be extremely thankful for the suggestions.

Thanks in advance

grumbler

I don't think you need them for all devices.

Start with one water arrestor, e.g. on the mains pipe or in the bathroom.

mazibee

grumbler said:

I don't think you need them for all devices.

Start with one water arrestor, e.g. on the mains pipe or in the bathroom.

@grumbler

Thanks for your reply.

One arrestor that was installed was on the main line (cold water line ) under the sink.

I looks like it was

https://www.screwfix.com/p/reflex-expansion-vessel-shock-arrestor-0-16ltr/8199V

Is there any difference between the above and

https://www.screwfix.com/p/sioux-chief-dw660-h-water-hammer-arrestor-bsp-connection/9813R?tc

lemondrops69

I has similar but only on things that used water from the tank in the loft, bath, shower etc. Valve was changed on the tank and all was good. I also read that the washer on the 'stop-male chicken' can wear and cause water hammer, but dont know if thats true

mazibee

@lemondrops69

Thanks for your reply.

We do not have water tank in the loft and we have a combi boiler.

grumbler

mazibee said:

grumbler said:

I don't think you need them for all devices.

Start with one water arrestor, e.g. on the mains pipe or in the bathroom.

One arrestor that was installed was on the main line (cold water line ) under the sink.

I looks like it was

https://www.screwfix.com/p/reflex-expansion-vessel-shock-arrestor-0-16ltr/8199V

Is there any difference between the above and

https://www.screwfix.com/p/sioux-chief-dw660-h-water-hammer-arrestor-bsp-connection/9813R?tc

Capacity  - 0.16L vs c.0.08L

Operating pressure - 3.5bar vs. unknown.

Different ways of connection and threads.

Generally, the bigger the capacity, the better the effect.

The mains pressure can be lower than the specified one, but if it's higher it reduces the efficiency of the device.

greyteam1959

The OP could try slightly closing the isolator valves on the appropriate taps etc.
Could possibly solve the problem for no money.
😁😁

fenwick458

the arrestors don't always fix the banging, and can introduce more problems. since i moved in my pipes have been banging, and I know exactly where they are but it just means cutting the bath panel out as it was fitted before the vanity unit. as a temp measure I have just closed the stop tap a tiny bit to stop the banging, but it does slow down flow when 2 things want water at the same time.
I have been contemplating an arrestor but have been told they don't always work. I'm going to have to cut the panel and do a proper job 

Moss5

https://www.bes.co.uk/adjustable-pressure-reducing-valve-15-22mm-22301/
Hammer may be caused by a tap washer getting the jitters, or long pipe-runs without pipe clips to support the pipe, it becomes a hose with whiplash.
The water pressure is an influence on the hammer and could be reduced by fitting the reducer (above).

grumbler

Moss5 said:

https://www.bes.co.uk/adjustable-pressure-reducing-valve-15-22mm-22301/
Hammer may be caused by a tap washer getting the jitters, or long pipe-runs without pipe clips to support the pipe, it becomes a hose with whiplash.
The water pressure is an influence on the hammer and could be reduced by fitting the reducer (above).

I don't think all this has anything to do with water hammer that is caused by stopping sharply the water flowing in a pipe.

Moss5

https://www.youtube.com/watch?v=xoLmVFAFjn4
1/4-turn taps are good at inducing the hammer, but you have to be stopping water with velocity.
The higher the water pressure, the greater the velocity.
The whiplash demonstrated by unsecured pipe is what may be causing the tapping inside a wall or ceiling.