Flushing Toilets and Closing Taps cause banging

[RK_London]

I seem to have a problem with a banging sound in one upstairs room (bathroom). When the toilet is flushed and sink tap closed I get a banging sound in one corner. I also get the same sound in the same place when I flush a downstairs toilet. I also get same sound when I close a kitchen tap which downstairs on the other side of house.

I live in a 4 bed detached property and I have recently replaced the pipe from mains supply to my house. I've also replaced boiler and cylinder and gone from vented to unvented system.

Any help welcome.

Thanks

 

[xd400]

Caused by water hammer. The sudden stop of water flowing. When you had the mains water pipe changed the water pressure may have increased so now you're getting the banging.

The only thing you can do is try and clip up pipes if they are loose. That may help but may not stop it altogether. There are ways to install arrestors at the points of the toilet or sink. They then absorb the shock to stop it transmitting down the pipes.

Alternatively install a water pressure reducing valve at the mains. That can absorb some overall and you can also reduce the water pressure if it's already higher than you need.

 

[RK_London]

thanks...if I reduce water pressure at mains will that affect the pressure of shower or is that controlled by the unvented cylinder?

 

[xd400]

thanks...if I reduce water pressure at mains will that affect the pressure of shower or is that controlled by the unvented cylinder?

For an unvented system the mains provides the pressure. So it will affect it. But also you don't want too much water pressure either. The regulator will help control it.

 

[RK_London]

Shower pressure is already borderline as had a pump on the shower when it was vented and now it's unvented shower not as good. Don't understand why all the noise from all the taps and toilets is located in one part of the house.

Might have to investigate getting the arrestors you mentioned

 

[opps]

Just out of interest. I get water hammer. I suspect it is from a pipe in a boxed section. Would expanding foam be a suitable clamp? I was wondering if drilling some small holes and squirting a load of expanding foam in will help.

 

[Alec_t]

Do you have a water cistern with a float-valve? If so, re-washering (or replacing) the valve may be a cure for water-hammer.

 

[denso13]

I live in a 4 bed detached property and I have recently replaced the pipe from mains supply to my house

Did you also replace the main stopcock in the house?

 

[RK_London]

@opps - I will need to put the foam idea to the plumber - I do think noise is coming from pipes in a boxed section
@Alec_t - I don't think I have a water tank with a float valve
@denso 13 - Yes the main stopcock in the house was replaced

Thanks everyone for your replies