Low water pressure - could the megaflo prv be the problem?

Question

I've got decent mains water pressure and flow at the garden tap - around 3 bar and 30 lpm. But the pressure on the first floor is about

0.8 bar, and the flow is under 10 lpm.

There's less than 3M height difference between the garden tap and the first floor tap level, so I'd expect to see at least 2.5 bar on the first floor.

The only thing I've got in my system that I think could be affecting the static pressure is a pressure reducing valve (prv), which is part of a megaflo system. Both the cold and hot water for the first floor taps appears to be after this prv. Here's a photo of the megaflo prv:

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The prv is the big thing in the middle of the picture, with a black cartridge screwed into the top.

The system was installed around 1999, so maybe the prv has become worn or clogged up or something.

I'm wondering if I should take the prv cartridge off and clean/service/replace it? Or am I barking up the wrong tree?

David.WE.Roberts · Accepted Answer

Can I add to this - what is the difference (if any) between a Pressure  Reducing Valve and a Pressure Limiting Valve? I have a PRV installed at the moment to protect the water softener  (selected by plumber) and this seems to be restricting the water flow even  though it has been opened up far higher than the static water pressure. I am planning to take it out as the static water pressure is below the 3.5  bar point at which you are supposed to fit a PLV. Cheers Dave R

John Rumm · Answer

There is often a cage type strainer inside the PRV that should be  checked and cleaned once a year really. If that has not been done, then  that would be a good place to start.

Grimly Curmudgeon · Answer

Depending on type, it can need re-set. I've had to re-set mine once in ten years, as it drifted down in pressure allowed through over that time.

Caecilius · Answer

Yes, I believe there is a filter in there, and I plan to clean that out when I take the prv cartridge off.

But I guess that it must be more than just a clogged filter, because that wouldn't change the static pressure would it?

Caecilius · Answer

That's interesting. I think the megaflo one is non-adjustable, but I guess I won't really know until I've got the cartridge out as I've found many supposedly sealed/non-adjustable things to be servicable in the past.

Low water pressure - could the megaflo prv be the problem?

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