Redundant heating system for water-carrying pellet stove?

Then a bit more constructively: It is not advisable to let the house cool down. Depending on the construction style - very light, for example in the Scandinavian style, or heavy with screed, bricks, etc. - briefly reheating a cooled-down house does not bring any benefits, has negative effects / works well.

Of course, we have already looked at some pellet stoves that are in operation in advance, and I was even positively surprised because I probably approached it with the same attitude as you.

I also excluded hot water generation in summer via pellet stove in my 1st post.

Best regards Judyyy

In summer, the hot water demand should ideally be generated by a solar thermal system.

Yes, here you are talking about solar thermal. And that will not work.

@ I am not quite sure about this now The idea is to cover the basic requirement of 19° C (which should not be cooling down) with a heat pump to improve efficiency and to use the pellet stove if necessary, which distributes the heat more or less in the house via Multiair/controlled residential ventilation/water. Since we want to integrate the staircase in the living room, the pellet stove will probably be placed very centrally. Is it possibly to connect a pellet stove with a fan to the controlled residential ventilation in order to better distribute the heat this way?

Oh, now I know what you mean

Since I'm not completely resistant to advice, I have already informed myself about it and wrote in my 3rd post...

Die Solar-Thermie fällt wohl aus aber dafür wollen wir eine 10 kWp Photovoltaikanlage, eventuell mit Warmwasser-Wärmepumpe.

But you can easily overlook something like that.

Regards Judyyy

Just a stupid quick question: why go through this quite extensive effort? The additional costs for the entire pellet system would probably power your heat pump with electricity for several years.