Loud vibration noise near stopcock/PRV

[tomted]

Hi everyone,

We've got a loud vibration noise that seems to be coming from the area around our stopcock/water meter/pressure reducing valve. Two plumbers have failed to sort it, so I'm hoping someone out there can give us some clues.

Here's the backstory:

• our combi boiler had to be replaced 18 months ago. Part of the reason was persistent leaks, which was a result of high water pressure in our area;
• when the boiler was replaced, a pressure reducing valve was fitted next to the stopcock and a shock arrestor fitted next to the boiler itself (see picture of 'old setup' attached);
• no problems for 18 months and then we suddenly started getting a very loud foghorn type noise which seems to come from the area around the stopcock/PRV. This happened when pretty much any tap in the house was run, hot or cold (see video attached of 'old sound'). I'm told foghorn noises are often associated with failing ball valves, but we don't have any ball valves, just fill valves, which have all been replaced within the last few years;
• so, plumber comes, decides to fit a shock arrestor in that area (see picture of 'new setup attached);
• we now have a new noise - it is more of a vibration than foghorn, but still pretty loud.
• If the PRV is set to 2 bar, it happens pretty often, again from pretty much any tap being run, but can be unpredictable.
• If the pressure is increased to 3 bar, it happens less often, but will still happen if a tap is opened only slightly, but also at certain points in the washing machine cycle (even when not filling). When the noise happens, if you run a tap anywhere, it stops immediately. If you run taps at full or near full blast, the noise never happens.

So I'm wondering what is going on. Seems to me that it is a problem with pressure. The pipework around the stopcock/PRV isn't secured very well, but even if I hold the pipes while the noise is happening, it doesn't stop the noise, so I think it is more than just loose pipes. Any suggestions would be really welcome.

Thanks

 

[cjg]

think you have hit the nail on the head, now find the pipe.

 

[Timmy D]

I’d change/service the stopcock, sometimes worn washers can make noise, however your noise is a bit extreme.

Then I’d remove and bridge components one at a time till found.

 

[Ben-gee]

I think the prv may be fitted the wrong way around, try reversing the direction of flow through it - ie turn it around.

 

[Last Plumber]

If the pressure is being reduced by a fair bit, you may need to install another PRV to bring it down and then down again if you follow that?
Sometimes the reduction in pressure is too far for one PRV to accomplish without making that kind of noise.

 

[cjg]

its not the water meter is is?

 

[Ricky]

i would possibly guess faulty PRV, i have just fitted one of similar make doing exact same thing, going for different make. I would have fitted the PRV and vessel down stream of the meter.

 

[PETE 123]

Check pressure in mini expasion vessel (silver ball) might help just a guess,