Firstly as long as the boiler is under 70kw ie not a commercial boiler then you can install it, note worcester product you are looking at is a domestic boiler but a large one and is based on commercial design so that's where people can get some confusion. I'm pretty sure also that worcester insist on putting anything above a certain size (I think it's 40kw but don't quote me on it) into a low loss header so as the boiler can keep up with demand.
The 50 and 65kw one's don't. Only if you use the RC35 control
The 50 and 65kw one's don't. Only if you use the RC35 control