The heat pumps I’ve seen pictures of look enormous compared to the boiler we have. It looks as if they need a bit of space around them, too, and the pictures I’ve seen have them located outside. We don’t have adequate free wall space outside, from what I can see of them, and if they can go in a garage, it would need to be a lot bigger garage than the one we have, because I actually use my garage for the car and there’s no way I would get the car in around the bulk of the present heat pumps I’ve seen pictures of. Maybe they have various sizes, I don’t know, but if not, I would say they could do with a re-design if there is only the one standard, bulky size I’ve seen, or people just won’t go with them.
I’m imagining there would be lots of upheaval to homes in order to fit them too, replacing pipework, installing adequate insulation, changing radiators (?), redecorating, etc. I don’t think a £5000 grant will go far in sorting all that out. I haven’t done any research into them, to be honest, so maybe some of my thoughts I’ve voiced won’t be the problem I think they are.