Mains water pressure concerns

[Big Gee]

Hi,

We currently have a combi boiler and are about to get it upgraded to allow for a new second shower room in the loft. Our intended new boiler (Worcester 35 CDI II) provides approx 14 lpm flowrate. Our mains has been measured at 1.5bar with 15 lpm flowrate which has been declared just sufficient.

Our water supply company, Thames Water, is only prepared to guarantee 1.0 bar and 9lpm flowrate. In addition I am aware that they are going to be lowering the water pressure in london to reduce the number of mains leaks. So I am not confident that our current mains pressure will remain.

My concern is should I invest over £3000 in this new boiler with the chance that over time the water pressure may drop and render it insufficient. Would I be better off spending even more money on a system that does not rely on the mains pressure.

Any comments would be very welcome.

Thanks

 

[kevplumb]

you wont get the same presssure /flowrate in the loft

 

[Kingsway]

There are other ways to improve mains pressure without relying on the water company

 

[ChrisR]

BG presumably if you had room for tanks you wouldn't have a combi now?

I'd put an electric shower in the loft room. Even the biggest ones only use about 4 l/min, and they do give you a backup when the combi fails.

That bigger combi would be a waste of money I fear.

 

[milliemop]

There are other ways to improve mains pressure without relying on the water company

could you tell me how as I would like to fit a combi but the mains pressure is not too good (0.5 -1 bar)

 

[AdamW]

If (when) they do drop the pressure to 1 bar, that would be a bit of a problem for many people in London: round where I used to live, 4 and 5 storey townhouses were common, with high ceilings too. So if you have an all-mains pressure system then you can only have bathrooms up to the third storey. But if you have an attic tank then you are screwed, as 1 bar mains pressure won't reach!

The only solution would be to install a tank in the basement and pump water upwards with a big pump. But with space at a premium many people have their basements as "proper" rooms, quite often for a kitchen.

Especially wouldn't want to be the owner of a top-floor flat in a converted London townhouse after that! "The appartment has great views across the park, is within walking distance of the nearest tube, and has no running water."

 

[brumylad]

companies would probably not be alowed to do it because as with disconection it would be classed as a health hazard ?