No its a large 4 bedroom house with two adults 2 growing children and a planned extension including a shower room. Its all about the DHW. But there are 11 radiators/towel rails and I wanted to fit a smart TRV on each one and create a few zones. Looks like I may be in trouble.

The other option is the Vaillant ecoTEC plus combination 938 but the opentherm mod on that is non UK supported.

Buying a new boiler and making the right decision is far more complicated than expected!