Thought some of you might like to know the best buys in Which?
Best combis:

Baxi Duo-tec
Potterton Gold
Vaillant ecoTEC
Vaillant ecoTEC(Larger model)

The Baxi and Vaillant were the only two boilers that met the claim of
91% efficiency.

Bottom of list we
Ideal Isar
Worcester Junior (Always thought these boilers had an over- inflated
opinion)
Potterton performa
Forgot the rest, but these boilers did not meet efficiency claim.

No open vent boilers were best buys but the top of list was the
Vaillant and at the bottom was the Potterton promax

The next boiler after the 4 best buys was a Boulter Buderus