Adjusting pressure reducing valve

Scuzi

Scuzi

Scuzi

Man of Honour
Joined
18 Oct 2002
Posts
20,431
Location
UK
On the water inlet to my house there is a pressure reducing valve fitted. It’s a relatively new build (~18 months). The chap who fitted the water softener suggested they are fitted for environmental reasons and can be removed or adjusted to increase the water pressure in the house.

xuoLFzT.jpg

If possible, I would like to increase the pressure coming into the house. When one outlet is on, any simultaneous use causes a drop in flow to the point it is useless. E.g. if the washing machine is on, the shower upstairs is terrible.

Can this valve be easily adjusted, and if so, how?
 
It can only adjust pressure, not flow rate.
Is it a 15mm model, if so a 22mm model would give better flow rates.
Look under the cap for adjustment, usually they are fitted because the incoming main is too high, so minor adjustments only.

Al
 
There's a brass flat head screw in the centre of the grey cap and there should be a sticker to say which way to turn it. Think it's clockwise to increase the pressure.
 
Thanks. I’ve turned the screw clockwise and the gauge now shows 3 bar. Can’t say I’ve seen any discernible difference from that so I’m guessing I’m **** out of luck!
 
Righty tighty lefty loosy, isn’t turning it to the right causing it to reduce the pressure, hence the gauge increasing to show its reducing the pressure by 3bar?

Edit - I think I am wrong but worth a shot if it’s not done anything noticeable.
 
Acme said:
Have you tried turning it up to 11 and ripping the knob off?
Click to expand...
I kept turning until it stopped increasing on the gauge. It will turn further but there is no increase gained. If it doesn’t work I usually progress to hitting it harder with a bigger hammer. I’ll be back later for emergency plumber numbers.

Kol said:
Righty tighty lefty loosy, isn’t turning it to the right causing it to reduce the pressure, hence the gauge increasing to show its reducing the pressure by 3bar?

Edit - I think I am wrong but worth a shot if it’s not done anything noticeable.
Click to expand...
I was working on the same logic as you but the marking on the screw indicate clockwise “+” and anti clockwise “-“. Turning clockwise increased the pressure from 2.5 to 3 bar.
 
That looks like a 15mm pipe, your never going to get a good flow rate from that if it’s your main pipe in either way if more than one tap is running

what’s the fitting underneath that one? Looks to be pretty restrictive also.

To increase the flow really the main cold pipe needs to be upgraded to 22mm which is a huge job.
 
Looks like a non return valve below, what size is the incoming mains on the stopcock?

**Stop ******:rolleyes::D
 
It’s been answered above, for environmental reasons, smaller pipes equals less flow which also equals less water use on the biggest culprits like hose pipes and showers. It’s also cheaper by a few pence.

I was referring to the internal pipe work not the blue pipe. In most homes it will go blue pipe to 22mm which runs through the house to the hot water system. It also splits off to 15mm and 10mm for showers, taps and toilets etc.

You’ll get rubbish flow when you turn on two taps if you only have a 15mm pipe running though the house, especially if one of those taps is early in the feed as water takes the path of least resistance. Things like elbows and ball valves can be very restrictive, especially on plastic push fit pipe and will reduce flow further.
 
It’s a 22mm pipe throughout so I’m guessing the flow coming into the house from the main is just a bit rubbish?

I did have a brown trousers moment this morning. After fiddling with the valve, all pressure disappeared with zero flow. Thinking I had somehow totally screwed up, the neighbour texted to ask if our water was off. The whole area had coincidentally lost supply due to a burst main.
 
Possibly. It will have an effect on the pressure even when fully open but it shouldn’t be drastic.

Silly question but I take the main valve is fully open and the valve at the meter is fully open too?
 
b0rn2sk8 said:
Possibly. It will have an effect on the pressure even when fully open but it shouldn’t be drastic.

Silly question but I take the main valve is fully open and the valve at the meter is fully open too?
Click to expand...
Not a silly question as I haven’t checked! Let me go do that this evening.
 
I think you need to be aware of a couple of things before you go diving too far in.

First you need to check what hot water cylinder you have, if it's UVHW then you need to make sure you're not over pressuring it by increasing the prv setting. This is very important.

As mentioned above pressure is only half the equation, have you tried cleaning the gauze filter that lives under the grey plastic head of the prv? Also checking the non return valve for any debris? Iso valves downstream are also great at restricting flow, work checking for them.

Have fun ;)
 
The valve is showing 3bar on the house side which is decent. Water mains pressure varies over the days/months and years so this protects your house from the variations which in some areas I've seen reports of 7 bar. The speedfit/pushfit will have a maximum pressure rating along with the pipe which has to include any water hammer shock waves etc.
 
I had issues on our new build in South Wales with crappy water flow.

For me, if I turned on all the cold water taps the pressure regulator showed almost zero (as you'd expect).. I lived with that for 3 years until one day I as fitting a water supply to the fridge and had to take the pressure regulator off due to it being in the way and that's when I saw it had an inlet filter that was blocked with some small gravel!! I changed the valve anyway and had much better water flow after that!
 
I think that’ll be my next port of call. The taps in the bathrooms have a screw in aerator and each of those had a considerable amount of small grit/gravel and what looks like compound in them. If that has made its way through, then I expect there might be bigger bits caught in the inlet filter.
 
You must log in or register to reply here.
Back
Top Bottom