I'd choose Faillant over Wooshitter, although only in the same way as I'd choose stubbing my toe over breaking my ankle.Thanks muggles. So assuming I had a choice of only Vaillant or Worcester, how many kw boiler do you recommend for around 13-14 radiators and a shower?
As for the kW output required, that depends on whether you go for a combi or the sensible route of having a smaller boiler and a hot water cylinder. If you have the latter, which would be my recommendation, then something with a max rating of around 18kW would probably be appropriate (although I've not done a heat loss calculation on your house so it's hard to be accurate). If you're going for a combi, size it to the hot water requirement and accept that the heating won't be as efficient and you'll only be able to use one shower at a time