Underfloor heating air-water heat pump. House too warm when the sun shines

We are not heating yet (NRW). But it won't be long now.

New building in solid construction, which was erected within 5 months of construction time starting from March until moving in. We are already heating diligently so that the place doesn't mold away despite [Kontrollierte-Wohnraumlüftung]...

Of course we heat ... otherwise it would be too cold for me in the bathroom in the morning ... and since we now have continuous rain for a few days anyway ... who wants to sit around in [klammer Kälte].

I now have the following settings for the heating curve: I have not done any adjustment yet

The return temperature at 0 degrees is too high, so the flow temperature should be somewhere around 40 degrees. Operating a heat pump at 40 degrees is like throwing money out the window.

Of course we stoke the stove, but it only heats the living dining area, there we have a constant 26 degrees

Of course we stoke the stove, but it only warms the living-dining area, there we have a constant 26 degrees

Haha obvious :-p But first make all the end-of-September heaters look like wimps