Multibloc parts


5 Aug 2008
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United Kingdom

The pressure reducing valve on this 2.1 bar RWC multibloc is leaking. Can I get just the pressure reducing part or do I need to replace the whole thing? Any recommendation as to brand?

If I replace the lot, my valve is 2.1 / 8 bar whereas a lot of the new ones seem to be 3 /6 bar. I presume either is ok? The cylinder says "maximum primary pressure 3.5 bar".


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Right, considering the lack of response I thought I would provide an update with what I've done...

It seems only the pressure regulating part is available, but from OSO and at double the price of a new valve. It's also an adjustable pressure valve (didn't realise this until I'd removed it) which is less reliable and more prone to leak so you are better off replacing it with this version. OSO changed from the old version to this new version in about 2011. 3 bar / 6 bar is absolutely fine. The working pressure of the tank is marked as 3.5 bar.

The valve was easy enough to fit. Unfortunately the new valve is 30mm shorter than the old one so I had to sweat on a bit more pipe. I did this further down the tank out of the photo because I didn't want to risk the heat affecting the tundish or any of the other plastics. It was my first time soldering 22mm and it took nearly 30 seconds to get the pipe hot enough.

The gotcha - and reason I'm writing this post for anyone else. On testing I found out the hose had perished and was useless - water spraying everywhere when the valve was actuated. The hose is a specialised part and you can't get it from OSO any more, or anywhere else. As you'll see in the picture, both ends are designed to fit into a compression fitting. The hose ends have a piece of pipe with a pre-formed olive. Tap connectors might have worked but I couldn't find a hose with tap connectors at each end. The solution was one of these flexible copper pipes from Screwfix with an olive and spare compression nut from the toolbox at each end.

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I presume you've read the regs and approved document as part of your ticket? I have. They are available here and they say

Page 9:
Work which is not notifiable includes... In any system, the replacement of any part which is not a combustion device.

Happy to learn about why my choice was wrong but it seems to meet the requirements of G3.17 to G3. 24.
I have, and I never said that the work was notifiable. I suggested it should be carried out by a competent person with the correct training. You have proved your incompetence by replacing the old valve with an unsuitable part. My original post stands
Work which is not notifiable includes... In any system, the replacement of any part which is not a combustion device.
G3 qualification has absolutely nothing to do with any combustion device, stop playing with things that you neither understand or are qualified to work on

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