Well, further to the thread I started on the 23rd, system's been upgraded by
a Worcester Bosch Combi 30 Si running 11 radiators, 9 of which have been
fitted with TRV's. Rads are piping hot when the TRV's are set at maximum but
obviously they're now all being adjusted down to a comfortable level. It's
going to take a bit of time but we are happy with it. The bath doesn't take
that much longer to fill than before but we have to remember to fill with
hot water first then once it's at a level close to where we want it, we top
up with cold.

After much debate at home, and comments from this NG, we have decided to
continue with the fitting of the Mira Sport shower tomorrow. It gives us
that extra flexibilty if something happens to the gas supply at any time.