I want to compile a shortlist of suitable boilers to replace my 1987 Worcester Heatslave Highflow (23kW). The current installation is "Open Flue" and gravity fed. The radiators are on a microbore circuit from a manifold and have the Yorkshire Maxitwin valves - so Thermostatic valves can't be readily fitted (I don't like them anyway)
The boiler is in an airing cupboard upstairs - and has a flue through the roof - with 2 right angle bends. Vents from the loft space supply air to the boiler. (The Gas Board service the boiler annually and are always critical of the ventilation although it passes the tests)
I want a suitable combi that will be suitable for vent / flueing through the roof. (Does the average gas fitter have the ability to get onto a roof to install a new flue and deal with the flashing?).
I will be happy to convert to sealed primary to get rid of the loft tank.
The airing cupboard is not on an outside wall so condensate removal will be a consideration.
Will I be able to get someone to change the boiler as I really don't want the upheaval of replacing my system (yet) in order to fit new radiator valves?
Any comments on what to aim for - what to avoid - how to just change the boiler and not the whole system, etc.