Whole house pump or just a shower pump?

[wywywywy]

Hi all,

Recently bought a house with a gravity feed hot water system, and I didn't know any better (been using combi boilers all my life) and fitted taps/showers throughout the whole house that are for high pressure systems.

The hot water pressure at the moment is around 0.3 to 0.2 bar downstairs, 0.2 to 0.1 bar upstairs. The cold water is mains fed and is around 1 to 1.5 bar. All cold taps (except en suite) are fed by mains.

The problem is, as you can imagine, the shower is pretty much unusable. Washing up and cleaning using the taps is quite difficult too.

Was considering getting an unvented hot water cylinder, as they seem to be the be-all-end-all of hot water systems, but main pressure isn't enough, the incoming pipes are too small, and re-routing the existing pipework is too impractical.

So I obviously want to get a whole-house pump and get at least acceptable pressure, but the question is what are the drawbacks of a whole-house pump? Are they really annoying and noisy? Unreliable? Low life expectency? What happens when I flush a toilet?

Or would I be better off just getting a shower pump, and replace all taps with traditional low pressure ones?

Please advice. I am not very clued up. And all plumbers/heating engineers who have come told me different things. Some seem to know even less than me. One even said no problem he can fit a Megaflo for me for £500!

Thanks.

 

[picasso]

a lot depends on your budget, I would go for an unvented cylinder using the existing tank in the loft and a single 2 bar pump, fairly straight forward to install and no need to upgrade the mains, as the pump is in the loft it would be reasonably quiet as well, depending on how the showers are piped it may be possible to have balanced supplies making the showers work better.

 

[wywywywy]

Use a pump to feed the unvented cylinder from the cold water tank rather than from mains? :O Is that even possible? To be honest it is not something I've heard of. If it works it could work quite well for me, because I actually do have a brand new unused unopened Megaflo in the garage that I was going to sell! But wouldn't simply a whole house pump work better in this case?

And also the outlet of the cold water tank is 28mm, I don't know if that makes a difference.

However I am not sure where the discharge pipe can go? The airing cupboard is not attached to the outside wall on any of the four sides.

 

[picasso]

A lot of houses in london have this set up, break tanks in the basement and a whole house pump for unvented cylinder/s, its definately possible, depending on which way your joists run its not normally too difficult to run the discharge pipe and the 28mm outlet from the tank can be used for the pump, as I cant see your house plumbing this is all guess work, maybe better to get an (experienced) plumber to have a look.

 

[wywywywy]

Sorry but what is the advantage of using an unvented hot water cylinder over the one that is in place already in this setup, if a whole-house pump is used?

 

[picasso]

noise from the pump is generally the biggest complaint when using shower pumps/whole house boosters and as they are normally fitted at the bottom of the hot water cylinder its close to bedrooms, the pump for the unvented can be put in the loft and the noise wont be noticable, if your not worried by noise go for the whole house booster.

 

[Kev F]

or use an accumulater, ive learnt something here didnt know you could pump an unvented

 

[wywywywy]

Thanks for the replies guys.

Didn't know what an accumulator is, so I looked it up. Seems like a brilliant idea :O Very expensive though!

So if I decide to use a whole house pump, as most of the cold taps in the house are mains fed, should I just get a SINGLE pump and have it fitted between the cold tank and the hot water cylinder? But the pipe is 28mm and the pumps are all 22mm, is it going to cause a problem such as causing a restriction?

Thanks.

EDIT: Salamander pumps are good, yea? How about Stuart Turner?

 

[MJN]

Was considering getting an unvented hot water cylinder, as they seem to be the be-all-end-all of hot water systems, but main pressure isn't enough, [...]

For what it's worth, we've got an unvented cylinder and 1.5bar mains pressure and it works fine - extremely well in fact.

Mathew

 

[OvertonPlumber]

"here didnt know you could pump an unvented icon_redface.gif"

Lets just be correct you can only pump a unvented using a breaktank not the main directly.

I like to use Grundfos MQ 3-35 Pumps fed of existing 50 gallon cold water tanks. The last one i did i reinstated the cold tank in the loft of the house ran 28mm poly down from loft into the garage. Mounted the pump behind the chimney to deaden the noise and it pumps directly into the balancing valve.
For ultimate power i guess id consider a 28mm balancing valve and the feed and outlet on the mq are 28mm and to reduce into the 22mm on a unvented is a limiting factor. But 3bar and 35 ltrs /min are pretty good and build quality on the mqs is far superior to ANY shower pump.
We use dual 500 ltrs accumulators on the big jobs when you have 7-8 bathrooms but the MQ is good for small residential.
I always say when we fit the MQ solution that they may have to double up cold water storage as the cold tank will empty in under 8 minutes on a 50 gallon!.

 

[wywywywy]

Hi all,

Just an update.

In the end I decided to fit a shower pump rather than a whole house pump, because I was worried about the noise, and had concerns about the size of the cold water tank & hot water cylinder.

The shower pump works quite well (wish I bought a 3 bar though) and I'm glad I didn't go for a whole house pump because the noise is really annoying.

However, that means my taps are still pretty rubbish. Looking online I found a Grundfos UPA 15/90 booster pump, which is an inline pump that looks like one of those central heating circulation pumps. It claims to be able to boost pressure by 0.5 to 0.75 bar. Now the question is, would I be able to use one of these to fit onto the hot water outlet of the HWC? At least my mixers would work properly if it works and it should be pretty quiet, and the price is quite reasonable too.

Another thing is, the horizontal side of the Surrey flange currently supplies the shower pump. Can this booster be fitted onto the vertical side of the flange?

Thanks.