Shock arrester, does it matter where?

[23vc]

Hi
Never previously had an issue, but since turning the mains off and going on holiday for a week, I now get a clunk from the general pipework (doesn’t seem to come from the stopcock) whenever a washing machine or toilet fill valve shuts off. I’ve tried turning stopcock up/down, doesn’t seem to help.
I’ve also got a PRV installed, which I could have sworn used to “absorb” a sudden shutoff as it used to make a noise and never used to get the pipe knock. But anyway, was thinking of trying one of those shock arresters that goes on the washing machine valve, if this is miles away from the toilet which is also causing it, is it still likely to work? Wasn’t sure if the position mattered as long as it’s all connected to the same incoming main.
Any advice or thoughts appreciated

 

[footprints]

Firstly shock arrestors can loose pressure or the diaphragm splits so they can fail, so the one you have might not be working. As a rule the arrestor should be as close as possible to the source of the problem.

 

[hard-work]

Firstly shock arrestors can loose pressure or the diaphragm splits so they can fail, so the one you have might not be working. As a rule the arrestor should be as close as possible to the source of the problem.

He hasn't got one fitted. Yes, fit as close as possible to the offending outlet. It may do the others, just suck it and see, before fitting a second. They can be pumped up has they have a shrader valve. Try not to fit on the hot outlet of a combi, as it may produced nuisance boiler firing.

Also use one on the cold inlet to a combi which has a plastic hydroblock. This will save leaks from the hydroblock.

 

[23vc]

Thanks. The only shock arresters I've seen seem to attach to a washing machine hose. Although further to my OP, it looks like the problem may just be one of the toilet fill valves, which used to shut off nice and softly (standard bottom inlet fill valve type) and now seems to shut off with a bit of a clunk, so I may try just replacing that valve first.