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.