Clunking PRV

Dear UK.D-I-Y,

I have a strange clunk in my airing cupboard! I have an unvented hot water system (tribune premier cylinder) with electric only heating as we=92re out in the wilds. Whenever a cold tap is turned off I can hear a clunk coming from the airing cupboard, none of the pipes in there are loose (they are all very solidly clipped), and I can isolate the noise to the Pressure Reducing Valve (PRV). It seems that the clunk comes specifically from this one valve. Is this something any of you knowledgeable types have seen (heard!) before? Is this a standard way for them to fail?

I have recently done a load of work to the system (moving a bathroom) but this problem came on some weeks after that was finished. I have tried fitting a shock-arrestor near the stopcock in the kitchen, but sadly this made no difference, would it be worth moving this?

Does anyone have any advice on whether or not it=92s worth changing the valve? The fact that it=92s an unvented system makes me a bit nervous about diving in and messing with it. If this is a standard PRV failure mode then I'll just change it.

Thanks in advance.

Reply to
TheTaffia
Loading thread data ...

UPDATE: Took the valve out and checked the strainer hoping to find something significant, but all that it had were a few tiny stones. All put back together and alas, still have a clunking noise when turning off the cold tap eminating from my PRV. Does anyone have any idea if a PRV could be the cause of this or is more likely just general water hammer? Maybe I should move my shock arrestor to be right next to the noisy area.... any advice is very much appreciated. My wife is heavily pregnant and I want to get this niggling issue sorted before she pops!

Reply to
TheTaffia

i would guess it's just water hammer, the shock of the running water being shut off at the tap sends a shock wave back up the pipes, where it slightly increases the pressure in the tank, and the prv pops slightly to relieve the pressure,

Reply to
gazz

Try moving the shock arrestor near the PRV, between the tap and PRV. Also replace the maintop with a full bore type. It may mean the PRV is on its way out, but worth doing what I said.

Reply to
Doctor Drivel

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.