you really want to get some opinions/quotes from local engineers tbh.
There are some questions that need looking at before you can say for sure what/if can be fitted. Where will the condense go? is the gas undersized? will the flue in the same position now be against the regulations? anywhere to put a magnetic filter and is one needed to protect the new boiler? does there need to be a scale reducer or mini expansion vessel fitted? can pipework route behind boiler? Is the wiring suitable for wanted new boiler?
these are the sorts of questions that an engineer looking at your job will questions and answer and suggest idea's on.
Thanks to all including jefaz and plumber0808
National company visited and agreed thir "exclusive" range would not fit.
Finally got a helpful local plumber to call who suggested a GlowWorm 35cx, We discussed personal discounted price but total seems a bit excessive even though I work for a national construction company and I spoke to his plumb centre account manager, perhaps thats why!.
He recommended several reasonable extras, and possible additional works, but taking all that into account, I feel the boiler install may be a tad excessive
Condensate could go to waste pipe under worktop below, gas is 22mm, flue is to gable wall (high enough to need step ladders), willing to include filtration though as heating is not fit to run, the flushing options are partly limited. Electricity was good enough for old pump and mechanical clock to run off dedicated std 3 pin socket in cupboard.
Cupboard is 600 wide (1500mm high from worktop upward to apex ceiling) so pipes could run up either side subject to clearance, thus Ideal+ is not out of the question, also from wall to door centre is more like 350 so depending on cover/controls the choice may be better than I feared.
Am trying to source more quotes in GL56 area this weekend, prior to decision early next week, but approved plumbers seem thin on the ground locally ??
Thanks again