These coincidences always occur - I was looking at the handbook for my
CH boiler using a Riello 40, when lo and behold someone else asks
questions about one. Well, hijacking a post is just plain bad manners
so here's my question.

My Riello is fitted to a Camray II Model 15/21 boiler by Boulter -
they were taken over a few years back by Worcester Bosch. The
Technical data lists 4 apparent model types - 15kW through to 21kW
with no physical differences to the boiler body, etc.. Does anyone
know what defines the different power outputs as the only thing that
seems to vary is the nozzle and the oil pressure ? I'm wondering
quite which one I have (can't find the original receipt) and then if
I've got the 15kW one, can I just upgrade with some easy component
change ?

Thanks
Rob