"Dave Fawthrop" wrote in message
...

I am thinking of replacing my conventional central heating and hot
water system with a gas combination boiler, for my four bedroom
extended semi, with one bathroom. My present system is 25 years old,
when I did the heating calculations and ended up with a 10kw boiler,
which works perfectly well with ample heat output, even in the coldest
weather. When I did the heating calcs, the house was *very* well
insulated, and I have continued adding insulation/double glazing over
the years, so it is now *extremely* well insulated. I am therefore
looking for a combi with less than 10kw output to central heating,
plus enough say 10l/m to the DHW.

Objective is to save space.

I have looked in Google Groups for old threads, and tried to answer
the questions which may be asked.

Kitchen tap gives 16l/m
Bath tap hot water gives 9l/min
Soft water.

Googleing for combination boilers only gives huge 20+kw models does
anyone here know of anything smaller?

As I will now be pressurizing the central heating pipes (copper with
Yorkshire fittings) does anyone expect problems with this?

firstly ignore the heating requirement and concentrate on the hot water
side - 40kW gives 16 litres per min approx - look for one that will modulate
down to your 10kW for the heating
FWIW - I have just had an Alpha CD50 fitted and am well impressed - this
modulates from 6.3 to 29.7 kW on heating and upto 32kW for water, it has a
small store for instant hot water and is wall mounted ( in loft on gable
end )
LMK if you want more info

Regards Jeff