I'm just about to start an extension on my house and as I will need to re-locate my current boiler, I wonder if it may just better to replace with a new one. It's a 3 bed semi of approx. 2000 sq ft and the boiler is a 15-20 year old Worcester Bosch 12/14 running 14 rads. The boiler has just been serviced and has no probs (the service sheet says it was running @ 97% efficiency!). The new extension will be approx. 1000 sq ft and I can either use rads or underfloor heating both up and downstairs. Would you think my current boiler is up to the task of heating the extra space or is it time to invest in a new one? If so, what type of oil boiler? thks