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

Endpoint for me is 28 degrees, enough.

Endpoint for me is 28 degrees, enough.

Return flow yes. Supply flow would be quite optimistic. But you will only find that out when it actually gets really cold.

The heating curve looks quite normal, very strange that it shows you any VT's of 65°...

I just discovered this here:

The endpoint for me is 28 degrees, that's enough.

I just found this, it is probably the actual value:

chewbacca, didn't someone write here that he spent a few hours intensively studying the [Gebrauchsanweisung] so that he can set his heating optimally? I think you won't be able to avoid that either.

30.9 degrees at 3 degrees outside temperature is way too high. The return temperature is only 0.2K below the supply, meaning the heating energy stays in the water. Probably all ERR closed?!

I would complain about the system. Nothing is right.