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

Heating curves are set slightly differently for each device, 28 22 0 doesn't say much now... For you, the values seem to be understood such that at 18°C you have a flow temperature of 28°C and at -12°C 40°C. That is already quite high.

Heating curves are set slightly differently on each device; 28 22 0 doesn’t say much on its own... It seems that in your case the values mean that you have a flow temperature of 28°C at 18°C and 40°C at -12°C. That is quite high.

What values would be considered normal?

Depends on the house and the energy consumption.

It depends on the house and the energy consumption.

The house is a new build, 170 sqm with underfloor heating, and I don't know the energy consumption yet because we only moved in this week.

The data should be in your energy certificate.

The data in the energy certificate have no significance regarding the actual heating load...