Heat pump, water storage tank, instantaneous water heater, wfK, underfloor heating, heating and cooling

I would say "what's not there can't break," and by the way, you neither have to pay for it nor install it nor manage it nor maintain it.

Every fireplace is a luxury hobby, to make it look good with a water jacket, no way. Heating element just to get rid of excess photovoltaics? I also have photovoltaics but with a photovoltaics surplus I don’t even turn up the flow temperature because what use would I have for three hot full baths in summer?

So yes, a lot is possible, but not everything makes sense.