Increasing Mains Cold Water Pressure and Flow Rate

[Ryan111]

Evening All,

We have just (3 weeks ago) got the keys to our first house. Central heating and condensing boiler currently being installed. Plumber has advised that our water pressure is low (just about enough for boiler but not ideal).

I’ve bought a pressure guage and have the following readings;
Static pressure - 3.1 bar
Dynamic pressure - 0.7 bar
Flow rate - 12L/min

I’ve purchased one of the ‘home boost’ pumps but it made little or no difference to the flow rate at any tap.

I have had the water main replaced from the meter to 25mm MDPE direct to the location of the boiler to be installed and taken the readings off the end of this so no internal pipework causing poor flow rates. With the house connected I get approx 9L/min through the kitchen and bath taps.

How can I increase the flow rate? The boiler spec’d will do 16.5L/min of hot water so want to bring the cold up above that to get the most out of our new thermostatic shower that’s being fitted.

 

[Ryan111]

I had considered that, but the boiler is being fitted on the ground floor and running the pipe work to and from the tank would be a pain!
We have a detached garage approx 2m from the house and an open trench between that I have considered diverting the main water inlet into the garage and fitting a tank and pump system to boost water pressure and flow. I have also considered an accumulator since the static pressure is reasonable....

 

[Ryan111]

I don’t know about that, I only had the customer side of the meter changed. I’ve got SW Water coming in a couple weeks to check but I’m pretty sure I’ve got above the minimum they are required to provide so they won’t do anything about it. I’m also pretty sure I’m on the end of the water main for our street so get whatever’s left over which doesn’t help matters!

 

[Ryan111]

How much are you paying to have that upgraded of you don’t mind me asking?

 

[Ryan111]

I’m going to check a neighbours pressure/flow and see how theirs compares. If theirs is the same then I’m pretty confident it’s just an area thing and I’m not going to benefit much from paying for a larger communication pipe

 

[Ryan111]

I figured that’s why the Home boost pump didn’t have much effect on my flow rate.

I’ve been looking at a system such as this - https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/172668430075

Would a break tank work in the garage being the lowest part of the house? If so, can anyone recommend a suitable tank/pump combo to feed the combo boiler and cold water to the house?

 

[Ryan111]

Budget is one of those things I am not set on. I don’t want to spend £300 and it still be poor, but then also don’t want to spend £800 if I don’t need too.

We have the space for a storage tank, so that is definitely an option. It is only the two of us at the moment, so Water needs aren’t massive but I would like to somewhat future proof the design at this stage rather than trying to do it retrospectively.

I’ve been looking at a 2-300L storage tank, I’m guessing this is in the right ball park? Can you recommend a suitable pump/tank combo? Af far as I’m aware you can link to other sites as long as it’s not a competitor and OCUK don’t sell water pumps/tanks (atleast not for domestic water anyway!) so there shouldn’t be a problem there...

 

[Ryan111]

Something like this.
https://www.whisperpumps.com/Dab-ESybox-Mini-Water-Pressure-System
Attached to a tank would give you fabulous flow and pressure. Variable speed means it only works as hard as hard as it needs to.
Open more taps, and pump speed increases, maintaining constant pressure.
If you go to the pressure boosting section of the site, you will see the major brands, as well as systems designed and built by ourselves in house.
On the site you will find tanks as well, although it's possible your plumber may have more suitable options. If you have time to chat, call the main number tomorrow and ask for Mark. Should be able to sweeten the price also.

I’ve seen that system advertised before but couldn’t find much info on it. I’m assuming any suitable water tank would work with that?

There is something very odd going on if you're only getting 12L/min on a 3 bar mdpe connection to the main. Is this measured before any other outlets so as to rule out other internal plumbing issues? I'm reading yes from your post.

I measured just under (2.9 ish) bar on the washing machine connector in the kitchen, then when I turn on the kitchen tap it drops down to 0.7/0.8 bar. If I measure flow rate at the end of the 25mm MDPE (before it even goes through the new stop ****) it’s 12L/min

 

[Ryan111]

It’s an older house (60’s built). Water will be for shower/bath and general use around the house.

I’ve only really considered combi system. I’m assuming you are talking about having a hot water tank somewhere?

 

[Ryan111]

I’ve just been round to a house 3 doors away who we know and measured their pressure, quite different from ours!

Static pressure - 3.2 bar
Dynamic pressure - 2.4 bar
Flow rate - 21L/min

I’ve got SW Water coming out on Wednesday so hopefully they can do something to increase ours! Hopefully it’s just a dodgy/clogged up meter or something simple and cheap to rectify!

 

[Ryan111]

Just to keep updated, SWW came out and have agreed that we are getting poor flow rate and have agreed to replace the communication pipe free of charge! The have said I will get the same and 3 doors down so I’m happy with that!