Our present boiler is a Geminox 10-50, about 10 years old. I am just toying
with the possibility of changing it, as I am concerned that there seems to
be only one maintenance company is the SE of England that can provide
maintenance.

I see that Vaillant have a 65KW Ecomax boiler in their commercial range. I
have used Vaillant boilers before, and I have found them excellent. The cost
is around 1800 to 2000 Pounds for the boiler, and there will be some fitting
costs.

I had someone around to estimate and he recommended a Keston C55 boiler,
which is a make I have never heard of. His all-in price, including fitting
was what seems to me to be a ludicrous 5500 Pounds. Leaving aside the price,
which I guess is negotiable, are Keston a decent brand, on a par with
Vaillant?