Solar thermal domestic hot water additional heating support?

Completely forgot: just forget it, it's not worth it. Despite funding from [Bafa]

Just like other extras in the house. Ventilation system, fireplace (with heating support), ETICS insulation, KNX, batteries (accumulators).

With the small difference that some extras are sensible and at least have some kind of cost/performance ratio, while others are pure money burning...

Heating support (underfloor heating etc.) through solar thermal systems unfortunately belongs to the latter...

Very interesting. Everyone knows that it’s not worth it. No one asks him about the heated area or last year’s consumption. For a 100m² house, I wouldn’t push it on anyone either. For a larger property, 10% could possibly become interesting under certain conditions.

Sure. The design of the heating system depends, among other things, on the usable area. How big the house is, how good the insulation is, how much reserve capacity the new system has? Don't know. An 800-liter combined stratified storage tank is becoming interesting. The 9.36 m² of its collectors (there have to be four) is somewhat tight. With 800 liters, five collectors would be better.

Exactly. We have a 1000-liter combi, 15 m² solar, and two completely separate heating circuits (low and high temperature). My goal is to only need gas in winter. My planning was not about "saving"... but about maximum self-sufficiency.

Here as an example 1000 liters and 14 m². From the end of April until today, mid-June, 1 m³ of gas per week, where it rained all week. (erste Grafik) That all the "not worth it" might maybe, possibly, under certain circumstances be worth it can be seen in the second graphic. That it is not a 100 m² house can be seen from the numbers, much more interesting is the comparison to similar households.

Hmm, I see no heating support at all... so completely off topic here...