Hammer Stop for Toilet Cistern

[Mr Pointy]

For some reason the washing machine & toilet cistern are now banging when the fill valves close so I'm looking for arrestors that are easy to install. There's an ideal one for the washing machine which has 3/4" BSP connections & just fits in line with the fill hose:

https://www.screwfix.com/p/sioux-chief-dw660-h-wat...



I can't find anything similar in 1/2" to go between the cistern fill valve & the flexi pipe feeding it (yes, I know flexis are the work of the devil). Anyone come across one?

[Xcore]

Replace the fill valve in the toilet

[RotorRambler]

You can get them that fit 15mm inline, compression fittings.
Could that fit where the flexi pipe joins the copper feed?

[fooman]

Toolstation sell 1/2 Shock Arrestors.

[Mr Pointy]

fooman said:

Toolstation sell 1/2 Shock Arrestors.

Yes, but then I'd need to isolate & drain the incoming supply, remove the 15mm stop valve end of the flexi, add in a 15/15/1/2" unequal T, then add in a short piece of 15mm & then put back on the flexi. I'd end up with a tower of bits low down which is very visible.

A 1/2" version of the washing machine device would be tucked up under the cistern, take a minute to install & be almost invisible.

[Wildfire]

I spent ages chasing water hammer around my flat, fitted a pressurised arrestor to the mains feed, two in line behind the washing machine, all helped, but never elmininated it.

In the end I put isolation valves on each outlet and shut them off. Turns out it was the bath mixer tap.

When we put a new bathroom in it went away.

[marrow]

Have you made any changes to the pipework in the house? Are any pipes now touching, perhaps behind walls or under floors?

Our toilet was perfect until a plumber fixed a toilet leak. During the fix, he pulled the cold feed pipe a bit tighter (a few mm) and presumably it is now touching other pipes behind walls/floors. It now bangs when the cistern is refilled.

[Mr Pointy]

marrow said:

Have you made any changes to the pipework in the house? Are any pipes now touching, perhaps behind walls or under floors?

Our toilet was perfect until a plumber fixed a toilet leak. During the fix, he pulled the cold feed pipe a bit tighter (a few mm) and presumably it is now touching other pipes behind walls/floors. It now bangs when the cistern is refilled.

No, that's the annoying thing, I haven't changed anything. It might be that the incoming pressure has gone up & now both the washing machine & the toilet bang every time & they aren't even on the same pipe run.

Just to add to the work I went to shut off the incoming supply & the stopcock is stuck solid. I've tried penetrating fluid, heat & gentle force & it's made no difference so it looks like that's the first crisis to sort out.

[GasEngineer]

If you can't find a 1/2" one you could adapt the 3/4" one with ..

.. one of these at the bottom
https://www.amazon.co.uk/Bushing-Reducing-Connecto...
.. and one of these at the top
https://www.amazon.co.uk/Reducer-Adapter-Connector...