"Dave" wrote in message
...
Thanks to all for the responses.
It looks like the answer is a Worcester Greenstar

Good choice.

running vented into a
direct heatbank

Sounds good.

with a zone
valve for the rads

Errm no. The rads taken off the heat bank using a pump and a check valve.

and a second zone valve for
the towel rails and airing cupboard rad.

Taken from where? The boiler primaries? Could be. Is there a need for the
zone valve when you want these on all year around? If off the boiler
primaries (flow and return) then the rails only operate when the bioler
does. If you want them on 24/7 then take then off the heat bank and use a
pump and check valve.

The boiler and cylinder (of
whichever type) will be in the garage
so the F&E tank will need to be in the
loft and the DHW will need a return pipe
to ensure hot water doesn't take
too long to reach the taps.

Can be done with a couple of check valves and DHW circulation pump.

Any other comments?

See above.