"Suz" wrote in message
...

Still chewing over with hubby what way to do CH and DWS.

Learnt a lot from all of you boys in the last few weeks - thanks. Reading
with interest the "Thermostatic or electric shower from combi" thread
posted
by Eno. Makes a lot more sense when you understand the terms without a
dictionary of gas and plumbing terms!

The latest brainstorm from us is thus:
Replace oil boiler and all tanks with condensing gas combi.
Leave crappy water supply of 15mm as is - (11 litres per minute) and plumb
it to all kitchen equipment - sink, dishwasher etc.
Bring in new 35mm water supply and plumb all "upstairs" stuff with new
water
supply through combi (and kitchen hot tap). Will feed 2 loos, 2 showers
and
1 bath.
This is after friendly plumber's advice that just upgrading the supply as
is
mightn't be enough for our needs as a family of five.

35mm will not be enough? See the water company, and see what they will
deliver in flow and pressure.

Combi will do CH and one large underfloor heating area and bathroom stuff.

Big story, one small question:
To avoid digging up lovely new tarmac drive, we would like to bring it
through grass to near the front door and then dig across paved step area
which would be relatively simple to re-lay, in under door area and
straight
up the hall (needs levelled anyway to tile, its like a dog's hind leg at
mo). But can we? Is it silly to bring 35mm water supply through a
hallway
in case of leaks etc? Is it stupid to put a gradual bend in the pipe just
to save a drive?

No it is not. See the water company first. Some only allow the shortest
route from the water mains to the house.

Like John's idea of the Mira 415 shower valve. Avoids Bart-Homer-esque
moments in the shower, and singed kiddies. Any drawbacks?

Ok that's 4 questions, I'll stop now.

Suzanne,

If you are bringing in a new 35mm water main, then why are you leaving the
existing 15mm main? The water company will charge you extra for two mains
entering a property. 35mm will be fine, assuming you will have the pressure
and flow, which most 35mm pipes do. See the water company.

2 showers, one bath, 5 people. I would go for a heat bank and a gas
condensing boiler. See Christian McArdles posting on the current thread Hot
water System. He has bought a new DPS Pandora heat bank and is fitting it
in his loft. The same price as a Megaflow unvented cylinder and no
overflows. This will do all you want in a hot water mains pressure system
and no cold water storage tank. Then fit a condensing boiler. The UFH side
is easy enough. See the Polyplumb or Speedfit web sites.
http://ww.heatweb.com

A combi will do what you want, but it will be a top of the range
state-of-the-art very expensive job. It may work out cheaper though and you
save space.

Yes fit the Mira 415 shower, or the Screwfix job - I posted the details. I
fitted a 415 for a friend 13 years ago. I have used it occasionally and it
operates very well. It reacts very quick to pressure fluctuations in the
system. You notice a pressure change rather than a temperature change.

Another suggestion will be to install a pressure equalising valve at the
main stop cock. One pie directly to a heat bank, or combi, and the other,
to the cold outlets. Then cheaper shower mixers can be used. The
equalisation valve will do all the house, inc the two showers. You will
have to price up two 415s and two shower mixers and a 22mm equalisation
valve. The valves are available from Plumb Center.



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