Low Water Pressure

[FRAN1870]

What about something like this? The you tube video shows it stabilising loads of outlets?

https://www.anchorpumps.com/stuart-...1jAFZQb-LySpQ_1GV24PjtSIiNSpC9thoCKt8QAvD_BwE

 

[FRAN1870]

Here's the video

 

[FRAN1870]

Assuming that will that stabilise the cold water pressure?

 

[dilalio]

You can pump the whole ensuite if required, but not with a digital shower pump which is controlled via an electronic switch.
A twin impellor pump such as a showermate would be required and this has to be appropriately sited (usually in airing cupboard down low next to cylinder). You'd also hear the pump every time the loo is flushed.
You'd ideally need a pump for each shower and these would need their own dedicated feeds for both cold and hot, from the CWSC and the HWC.
Accumulator needs a loading pump to charge it and these have noise and space overheads - look at my photo above: the pump is on the floor between the megaflo and accumulator and we put it on a concrete slab with fibre underlay below to try and restrict operating noise. The whole lot was eventually hidden inside wardrobe space with sliding doors.

Quoting myself here but I think I covered what you need to know @FRAN1870
Bigger tanks and pumps on draw off side.

 

[FRAN1870]

Thanks for being patient with me on this ... its all very new. In a nutshell you have an unvented HWT and with a cold water accumulator that is charged by a pump (I assume that controller is a bit more intelligent too)
The difference here is that if I decide to stick with the two electric showers for now then I only need to boost the mains so that the showers aren't starved when I flush the can? This also paves the way if I want to change to an unvented HWT in the future because as your installation proves I would still need to boost the mains anyway?

Those Stuart & Turner tanks look like the answer. some come with the pump attached, some come with a separate pump.
I assume I could in theory put the pump on the first floor (in the airing cupboard) and the actual tank in the corner of the kitchen?

They claim silent operation so I guess my question is if anyone has any experience of these tanks and if they are noisy or not?

 

[wwwebber]

Unvented + accumulator = lots of money. Fair one if you've got the cash and the spare floor space but a large loft tank + pump is a much cheaper solution to boost & protect your cold water flow for your existing leccy showers.

If you do go for the accumulator and then go for unvented in the future you will need the accumulator to service the unvented cylinder AND your cold water flow to your mixer showers as pressure needs to be equal on both hot and cold for thermostatic mixers to work properly. So carefeful planning of accumulator capacity and flow is crucial here - especially as it will be indirectly boosting 4 feeds simultaneously if you have two mixer showers running at the same time.

 

[JohnD]

Apart from your showers, you don't need much pressure. Basin taps, WC cisterns and bath taps don't need to be pumped.

That would reduce the noise and possibly the cost.

I would guess the showers will be used less frequently than the other outlets.

 

[FRAN1870]

If I go for a larger tank in the loft then (assuming it's big enough) can this serve a dual purpose of gravity feeding the current hot water tank and also as a reservoir for pumped water to the leccy showers?
i.e. will I need two CWTs?

 

[wwwebber]

If I go for a larger tank in the loft then (assuming it's big enough) can this serve a dual purpose of gravity feeding the current hot water tank and also as a reservoir for pumped water to the leccy showers?
i.e. will I need two CWTs?

Yes, make sure its big enough and give priority to your showers.

 

[wwwebber]

I see in newer threads of yours that you're going down the accumulator route ? - that's fine if so but be carfeful. How many litres per min are you hoping for out of it ? And are you still using it for two leccy showers and an unvented cylinder ?

 

[FRAN1870]

Not decided exactly which one yet but I’m probably looking at min 100ltr

It’s not really about increasing flow, just more about mananging drops in flow / pressure.

The plan at the moment is this

1: install cold water accumulator
2: leave one electric shower in main bathroom
3: pump hot from existing tank to a mixer in en-suite
4: Possibly upgrade to an unvented hot water tank in the future.

I can’t do step 4 without solid mains pressure right?

This might change next week when Severn Trent come out to do flow / pressure checks at the road.

From my outside tap I get about

10ltr/m at 3.5bar when no other taps are running ... when someone flushes or turns another tap on the pressure drops to under 1 bar and flow around 6ltr/m

I need to know what I’ve got at the road, it’s a shared supply with next door so it’s perfectly possible that my previous neighbour (who has a Combi) could of reduced my flow to increase theirs?

 

[fezster]

Keep in mind the actual usable capacity of an accumulator:

Using Precharge = lowest dynamic pressure,
Vessel volume V and
Static Mains pressure M, (all pressures as measured on gauge)
Stored volume is given by V(1 - (P+1)/(M+1))

Read more: https://www.diynot.com/diy/threads/accumulator-again.493171/#ixzz5WLvkD4TH

 

[wwwebber]

Not decided exactly which one yet but I’m probably looking at min 100ltr

It’s not really about increasing flow, just more about mananging drops in flow / pressure.

The plan at the moment is this

1: install cold water accumulator
2: leave one electric shower in main bathroom
3: pump hot from existing tank to a mixer in en-suite
4: Possibly upgrade to an unvented hot water tank in the future.

I can’t do step 4 without solid mains pressure right?

This might change next week when Severn Trent come out to do flow / pressure checks at the road.

From my outside tap I get about

10ltr/m at 3.5bar when no other taps are running ... when someone flushes or turns another tap on the pressure drops to under 1 bar and flow around 6ltr/m

I need to know what I’ve got at the road, it’s a shared supply with next door so it’s perfectly possible that my previous neighbour (who has a Combi) could of reduced my flow to increase theirs?

ok

3. You need to ensure that your hot & cold to the mixer are the same pressure / flow or it wont work - how do you propose to ensure this ?
4. You can if you feed your unvented from the accumulator. However, the accumulator needs to be big enough to service your unvented cylinder and the cold water feeds to both showers for long enough for two simultaneous showers which I think is what you want. The 165l (storage not capacity) will certainly not be sufficient. I don't even think it will be sufficient for anything that you intend to use it for bearing in mind a typical 10 min shower may use 165l of water anyway.

Or you could just put a loft tank in and pump your hot and cold to both showers

Good luck with Severn Trent - if you get the flow you need then you simply go invented with mixers all round - job done.

 

[FRAN1870]

Sorry I’m a bit confused about the same pressure bit? Surely any mixer will be limited by the feed with the most flow / pressure?

And won’t the thermostatic mixer deal with some of the fluctuations?

I get the quantity of water issue but in the future I can get a big unvented water tank and job done.

In the meantime a 16l min shower won’t use 16l min hot water from the tank because I’ll be mixing it with cold?

For the sake of buying a pump I think I’d like to try this option first

 

[FRAN1870]

Although yes a cold pump from a tank is an option too ....