R
Ray Stafford
18kw for the whole thing is crap though ray.
Why? We used to allow 8,000 or 10,000 BTUs (BTUs, not KW) for hot water, and everyone was happy.
Sure, if I had a 16kw heating load and an unvented cyl, I would opt for a 24kw boiler. But I don't think it would be miles better than an 18kw. Better, yes. Miles better? Not really...