What if...

[Nix]

Anything is possible NR!

To simplify my set up so that even the missus can do it, I simply need to isolate the mains completely (NB - you'd have to do this, even in a SHTF situation/blackout), and connect my inverter to the house and I'm away! Takes about 30 seconds. Then you can treat the house as normal but avoiding the big hitters like kettles, washing machines, electric cookers, etc.

Those plastic speedfit jobbies are brilliant, I've used them quite a few times now and, yes, they would be a preppers dream to use. Only problem with pumpless HW/CH set up utilising a boiler is that the boiler would be too hot ie it has to have a fast flow of water to stop it from over heating and cutting out. A gentler heat source would probably do the trick ie those solar water panels. Matter of fact, I think I remember some of those set ups are capable without a pump anyway? I'm pretty sure of that when I researched them many years ago. Definitely worth checking again.