Christian McArdle wrote:

I have pondered for a while the idea of a mains pressure hot water system
but am really concerned about the lack of pressure at the upstairs shower.


Assuming that the mains pressure and flow is good, I'd do it the other way
round. Have the shower (and possibly kitchen tap) off the combi, and run the
bath from the cylinder, possibly using the pump.

Of course, you shouldn't rule out a mains pressure storage system which
gives the best of both worlds. I've just collected such a system this
morning, a 180l DPS Pandora. I'll let everyone know if it works once it is
finally connected up.


I've got one. Shoehorned the HW tank into the loft. Saves a lot of
space. Plumbing is more intricate - lots of safety pipes to dump
pressure outside etc, but overall performance is better than anything
else. Combis have pressure, but no flow rate IMHO, unless you go for a
really BIG one. Combis need to have heating capacity for peak hot water
flow. Mains pressure tank? You have three or four baths worth on tap all
teh time. Boiler needn't be as big.

I'd only use a combi on a strict budget, or in a small house with no
room for a HW tank.

I'd never use a gravity fed header tank unless teh local water supply
was known to be highly unreliable.

Here, water is 100% reliable, but electricity is not. No sparks means no
boiler. But HW tank is good for several baths, aga needs no psarks to
cook, and open fires take cxare of heating, and candles just about sort
out lighting. And battery radio allows local news coverage of 'national
electrical crisis'

AND I can recharge its batteris from the car.