new boiler for a boilermate11

Hello to all, My customer has a suprima 120 and a 200ltr boilermate 2, installed a few years back, they need a new boiler of 36kw and have 110,000 btu/hr in radiators, my dilemer is, the boiler i've sized is 130,000 btu/hr and even if i drop the boiler kw, the boilermater states ''use upto 100,000 btu/hr only'' which is less than my minimum, should the whole system be scrapped or can i get round this with the existing 200L thermal store and a higher btu/hr than stated in the manual.

I think you need to read the book
Down load from Gledhill.
But I think you have got it wrong.
4 bed house 1 bathroom
At THetford 40.000 BTU boiler.
Bit tight but works.
My self would have said a 50,000 on that one.
See what I mean!
Mike.