Hi All, I'm after a bit of advise from people who possibly know...... and even from those that don't . We are having a new extension built and need to move a 30+ year old standard boiler. Therefore we have decided to remove the old boiler and install a condensing combi in the new location. We have had four quotes, all roughly the same price but with different size and brand recommendations, hence this post. Quote one, 32kw Worcester Bosch CDi Quote two, 34kw Worcester Bosch CDi classic Quote three, 28kw Vaillant Eco Tec Pro Quote four, 36kw Worcester Bosch CDi What I don't understand is why the difference in capacity? It's only two or three l/minute hot water delivery difference between all of them. According to the latest guy, we get 18 l/minute mains water. All quotes were from apparently ex boiler engineers. Any advice appreciated.