Of course I should have mentioned that cost is a factor.

Those thermal stores look a great idea but they look pricey.

I suppose a combi is the cheapest option, but I have a feeling it won't be
up to the job, simultaneous use, bath filling. I only have 3 bed semi - but
for resale and our own use, perhaps combi isn't the way to go.

I guess if I go for anthing other than combi and consdidering I'm doing the
whole system, except rads & pipework, I should not replace with old hat tank
& cylinder. I suppose I can get a decent regular boiler for not much, is
condensing worth it?

What are those German boiler manufacturers alluded to?

What sort of cost am I looking at for boiler, heat store, controllers?

--
Mike W