Hi, I would like some opinions & recommendations from heating engineers on the subject of a replacement boiler please,we have an ageing open vent baxi wall mounted boiler in the garage that must be 25-30 yrs old but keeps chugging away but I'm sure is hopelessly inefficient,the rest of the heating system has been upgraded in recent yrs with new rads,trv's etc. we have a 3 bed detached house 1950's era, hot water tank in upstairs airing cupboard,water tanks in loft etc.we don't want to go down the combi boiler route but would like to stick with an open vent boiler again keeping things simple & costs bearable. My no1 concern would be reliability & customer support in the event of a breakdown etc, after lurking on this forum for the last 12 months & reading many similar posts I've narrowed down the choice ( in no particular order) intergas,viessmann,valliant,ideal. I fully understand that an engineer that installs a certain brand will have a preference for that brand but also that installation can make all the difference to the longevity of a new boiler aswell. So please if you could give me the benefit of your industry experience on a choice of open vent boiler that would be great,