Andy Hall wrote:
On Tue, 12 Oct 2004 11:00:57 GMT, "John Orrett"
wrote:



Thanks for that. Don't know why the guy in the shop insisted we need
a combi. They are not plumbing merchants, so there would be no extra
finacial gain for them.


OK. Basically what he is saying is that the taps are of a design
that is intended to run on mains pressure (hot and cold) rather than
from a roof tank arrangement. The path for the water through the
tap is smaller in those intended for mains use.

This is quite a typical scenario for taps orginating from countries in
continental Europe - often Italy, Spain, Denmark.

Not actually sure where the taps originate from Andy, they were just part of
the showroom layout for that particular suite (whose name escapes me
anyway).

snip
At present we need both the immersion and the boiler to give us a
decent bathful of hot water.

OK. Is that because the boiler on its own heats the water too
slowly or not to a high enough temperature or some other reason?

Basically because the immersion tank itself does not give enough hot water
due to its volume. The boiler is the 'top up'


If your new bath is a similar size to the old one, and you can
happily fill it at the moment, you don't need a new boiler.

My wife wants one of these 'shower baths', the ones with a bulge at
one end. I don't know capacities or volumes of our standard bath
compared to a shower bath, but it looks to me like it would need a
lot more hot water or end up with half a bath!

Ah... that's new information.

Does your wife's love of baths mean that she is like to want a good
flow rate on the shower, e.g. for washing hair etc.?

No, the shower is for me!

If so, and you are thinking about a combi, then look very carefully at
performance. An 11lpm model would produce enough water in the
winter to run a small shower head with fine jets but not particularly
good flow. If she would like good flow, then you need something
producing a good 15lpm. Is this bath/shower likely to be the only
use of HW simultaneously in the house, or do you have a second
bathroom or other substantial use of water? If so, and simultaneous
use is needed, then a larger combi would be needed and may be
marginal.

Just the one bathroom. If we need a top up of water then as said previously,
I turn the central heating down for an hour so the boiler has enough hot
water to finish off the bath.
snip


Then the crucial question is how deep does she like the water to be? I
am pretty sure I know the answer to that question. Don't forget to
factor Archimedes into the equation, but of course be diplomatic with
your wife about that :-)

Duly noted :-). But yes, on the full side.

If you work on the premise that a simple combi, without any form of
storage will produce its specified rate of bath temperature hot water
in the winter, then that will give you the worst case time for filling
the bath.

Many thanks again Andy for your help.
Cheers
John