Low Flow/Pressure

[hshah]

We have the following system (very high level):

However, we are finding that if the shower is on upstairs and someone else turns on another tap downstairs then the shower is drastically affected. Even with any of the showers (upstairs or downstairs) when turned on on their own, the flow and pressure are pretty bad. I would have expected that with a 300l Megaflo and two boilers, all provided by a 25l/min mains, it would be far better.

This is a 6 bedroom (4 shower) property, so if you can't have more than one outlet on at the same time then it is quite a big problem.

I am assuming that I will need an expert to come in and look at the system, but before I do that does anyone have any idea where the issue could lie?

 

[Ermintrude]

Sounds like you either have a massive restriction or no water flow/pressure. Didn't your engineer check this all out before install? 25lpm? That's cack for 6 bathrooms mate. You want more like 70 to 120lpm . So your going to need a 3000l break tank and a monster pump set.

 

[hshah]

Sounds like you either have a massive restriction or no water flow/pressure. Didn't your engineer check this all out before install? 25lpm? That's cack for 6 bathrooms mate. You want more like 70 to 120lpm . So your going to need a 3000l break tank and a monster pump set.

Something is definitely affecting the water going upstairs. I was just in the shower now (first floor) and someone turned on the kitchen tap to do the dishes... I had to shout asking them to turn it off.

25l/min should be enough for 2 outlets simultaneously thought right?

I don't have the space for something that holds 3000l and we will rarely have that many outlets on at most. 2 showers and 1 tap on at the same time is probably about the maximum. I was looking at something like these:
h t t p : / /uk.grundfos.com/products/find-product/home-booster.html
h t t p : / /anglianpumping.com/products/aps-house-booster-1200---mq

 

[Dotty]

Neither of them will do the trick.

 

[hshah]

What do you guys suggest?

The builder we had that advised us and installed everything is saying that it isn't his fault and that the above mentioned products will solve it. I don't trust him any more which is why I have come here.

 

[Ermintrude]

You haven't got a balanced cold and I bet megapoo iS fed by 15mm

 

[PlumbBobBob]

that's your problem "the builder did it" you need to get a plumber in to look at your system

 

[Dotty]

He's not a plumber that's for sure! Does he have an unvented ticket because if he doesn't your whole installation could be dodgy.

Pound to a pinch he doesn't.

You need someone in to go over it all.

But to be honest Ermi has nailed it.

 

[hshah]

Sorry, I'm a computer analyst... what does "balanced cold" mean?

All the pipes coming in and out of this so called "megapoo" are 22mm. Mains pipe into the house is 28mm.

 

[hshah]

Any recommendations of someone decent in or around the Uxbridge area who can come and assess the system?

 

[hshah]

*duplicate post deleted*

 

[hshah]

Please let me know if I am barking up the wrong tree here, but what about a 2000l potable water tank underground in the front where the mains water comes in? Then a pump from there to continue on with the existing system.

I have worked it out as:
4 x Bathrooms at 35l/min for 10 min = 1500l
4 x Taps at 10l/min for 10 min = 400l

This is over estimating as well, so maximum consumption in a 10 minute period is 1900l. To fill a 2000l tank will take 80 mins.

Does that seem feasible? What sort of pump would I need? I would want to keep the pump outside in an insulated box.

 

[Ermintrude]

You need a booster set for cold water. Decent one £2k tank £1500 labour £1500 depending on works req. balanced cold basically means that the cold and hot are of equal pressure. Get a G3 lad in from here to give it a service and inspection before u start setting away pumps and tanks

 

[hshah]

You need a booster set for cold water. Decent one £2k tank £1500 labour £1500 depending on works req. balanced cold basically means that the cold and hot are of equal pressure. Get a G3 lad in from here to give it a service and inspection before u start setting away pumps and tanks

Ouch, that is a bit more than what I was expecting.

When you say G3, what does that mean?

Will definitely get someone to have a look before buying anything, but can you give me an idea of what sort of pump and tank that would be required. There is so much online that I don't know what I need, and I would like to do some research before getting someone round to have a look.

 

[Plumbstar Tom]

G3 is the unvented ticket meaning the plumber is qualified to work on pressurised systems (over 15 litres)

Its quite hard to give much more help until someone gets round there to have a look

 

[Chalked]

Hi.
G3 is a qualification that you need to work on unvented systems. Rightly so too, as installed incorrectly, they can literally turn into a bomb!

if I lived a little nearer I would pop in and have a look at what you have and advise a solution.

6 beds is a large house. And there are lots of options.

Could you you post some pictures of what you have?
Ermintrude is correct, but if you have small pipework, the best pump in the world won't make much difference.
If your post count is not enough to post pictures, you could email them to me and I will put them on.
send them to [email protected]

 

[hshah]

Hi.
G3 is a qualification that you need to work on unvented systems. Rightly so too, as installed incorrectly, they can literally turn into a bomb!

if I lived a little nearer I would pop in and have a look at what you have and advise a solution.

6 beds is a large house. And there are lots of options.

Could you you post some pictures of what you have?
Ermintrude is correct, but if you have small pipework, the best pump in the world won't make much difference.

Thanks! I am not at the property until Wednesday so will send you what I can then

 

[Ermintrude]

I can recommend adding as many 50l dhw expansion vessels as a good solution. It's cheaper....
67 expansion vessels aught to do. What are they about £:60 a pop. Only joking!!!

Upload a few pictures and let the pig see the trough.

 

[hshah]

Pictures are here:
[DLMURL]http://www.hirenshah.co.uk/plumbing/[/DLMURL]

 

[Chalked]

Having looked at your pics. I think the main problem lies with something you haven't mentioned, but a clue lies in one of your pictures.
you seem to have a water softener of filter. This is connected through 1/2 washing machine valves and small bore hoses. All of this will restrict flow. Could do with a picture of the softener and possibly the cold inlet to your cylinder.

 

[hshah]

Having looked at your pics. I think the main problem lies with something you haven't mentioned, but a clue lies in one of your pictures.
you seem to have a water softener of filter. This is connected through 1/2 washing machine valves and small bore hoses. All of this will restrict flow. Could do with a picture of the softener and possibly the cold inlet to your cylinder.

I'll take some more pictures when I go back there tonight. I tried bypassing the water filter by turning the blue taps off and opening the valve in between. However I did notice that I can't seem to shut it off... with the softener taps off water was still flowing to the tap in the sink above.

 

[hshah]

Having looked at your pics. I think the main problem lies with something you haven't mentioned, but a clue lies in one of your pictures.
you seem to have a water softener of filter. This is connected through 1/2 washing machine valves and small bore hoses. All of this will restrict flow. Could do with a picture of the softener and possibly the cold inlet to your cylinder.

Pictures added to my hosting. I tried bypassing the water filter by turning the blue taps off and opening the valve in between. However I did notice that I can't seem to shut it off... with the softener taps off water was still flowing to the tap in the sink above.

 

[Riley]

Is the filter/softener under the kitchen sink? If so, if it is a softener the water shouldn't go to your cold kitchen tap anyway as this should remain on hard water. I do agree though that this will probably affect your flow to the UV cylinder though

 

[hshah]

Is the filter/softener under the kitchen sink? If so, if it is a softener the water shouldn't go to your cold kitchen tap anyway as this should remain on hard water. I do agree though that this will probably affect your flow to the UV cylinder though

The softener is in the utility room, which also happens to have a sink in it. The grey pipe coming off the mains, just before the right most water softener branch is the one going to the kitchen sink. The utility room has the Megaflo and is where the blue mains pipe comes out... all the pictures (apart from the boilers) are from the same room.

 

[hshah]

Got jase158 (http://www.ukplumbersforums.co.uk/i...oking-g3-certified-plumber-uxbridge-area.html) coming round on 2nd January to have a look. Fingers crossed he can sort it out

 

[jase158]

So been this morning, water board report 24l/min at meter, I got 18l/min at stop tap, outlet of water softener, garden tap, and after ISO to taps.

8l/min from all downstairs outlets, 6l/min from upstairs.
2 x taps on at same time reduces down to 3-4 l/min

same pressure on hot and cold
same pressure on hard and soft (except garden tap)

unbalanced hot and cold, so not a filter, multifunction valve or a pressure reducer problem!

so obviously taps, but 1x kitchen tap, 1 x utility tap, 4 showers, 4 basin taps, and 1 bath tap all the same??

All taps on flexis supplied with taps, all showers and bath taps wall mounted!

Any ideas?

Issues are:
not enough flow to each shower,
when in shower, flow drops dramatically if downstairs taps used causing risk of burning,

The balanced cold should be sorted but not likely to cause an issue at the moment!!

 

[dancinplumba]

And what is the pressure ?

 

[dancinplumba]

All you have given us is flow rates

 

[jase158]

2 bar at the garden tap!!

 

[Chalked]

Very poor water main for that size of house. Plus restriction through water softener and various restrictions in high pressure suited taps.
two fixes.
1 replace complete water main to street ( only if standing pressures are good)
2. Install break tank and pump set after the water softener.

 

[jase158]

Water softener not causing a restriction,

the question they have is if taps only produce 8l/ min, why can't they feed 2 x taps at once, surely 18l/min, split into 2 should be able to provide 2 x 8l/min taps!!

and surely it doesn't matter what's coming in as each tap only produces 8l/min maximum so surely 18 l/ min should be plenty to feed 2-3 outlets at the same time shouldn't it?

the only thing I can think is the poor outlets are causing mega issues?
from 18l/min down to 8 is a massive restriction!!!

 

[jase158]

And even more onto that, if the pressure was increased to say 30l/min the outlets would still only produce 8 l /min so why and how would increasing it make a difference?

 

[dancinplumba]

2 bar at the garden tap!!

Is that running ? What at other outlets ?

 

[jase158]

Very poor water main for that size of house. Plus restriction through water softener and various restrictions in high pressure suited taps.
two fixes.
1 replace complete water main to street ( only if standing pressures are good)
2. Install break tank and pump set after the water softener.

Water main has been replaced 25mm all the way back to meter!!

 

[jase158]

Is that running ? What at other outlets ?

Standing pressure!!