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

A problem in winter is definitely also the low sun; in summer it stands higher and may be prevented from shining in unhindered by the roof overhang.

Make sure that the underfloor heating is generally running at the lowest possible temperature. That is more effective than a possibly existing thermostat, because the underfloor heating then physically is no longer able to heat the room further when the sun is shining.

Thank you very much for your answer. We have the heating system from the brand Novelan. But if we lower it by 0.5 degrees, for example, doesn’t that also make the water warm up more slowly? Take a look at the attached picture; this is the current setting:

Window open. It’s sometimes quite nice – even in winter

We have a residential ventilation system, so the windows basically always stay closed.

The flow temperature is centrally set by the heat pump via the heating curve configured there and is not defined at the thermostat. With the thermostat, you may at most throttle it, and the underfloor heating initially remains warm. Thermostats are not useful in new buildings - but that is another matter.

Underfloor heating basically has little influence on overheating caused by the sun.

Roller blinds and/or venetian blinds at the bottom are not a good solution for us in rooms where people are currently staying because we like to have an unobstructed view outside and both bother us. Venetian blinds are certainly a bit better than roller blinds, but it’s still not really great from the inside when they are down. When you are absent, it is of course the best solution to simply close the shutters so that it doesn’t heat up.

We have now built a terrace roof over most of the south side with an extendable awning underneath. In strong sunlight, simply extend the awning... okay, you can’t look up at the sky anymore, but you have a completely free field of view straight ahead and the sun doesn’t shine into the windows, yet it remains pleasantly bright inside. Since the awning is 4.5m deep when fully extended, we can almost independently of the sun’s position shade the windows from the outside when necessary.

Regarding residential ventilation: we have that too, but if more energy comes in from outside than is needed inside... what is wrong with opening the windows? You can’t get the heat out any faster, and the ventilation system has absolutely no problem with that.

The flow temperature is set centrally by the heat pump according to the heating curve configured there and is not defined at the thermostat. With the thermostat, you may only throttle it off, and the underfloor heating remains warm for the time being. Thermostats are not useful in new buildings - but that's another topic.

Underfloor heating basically has little influence on overheating caused by the sun.

How can I view the heating curve? Our plumber for the sanitary area is currently not responding; they are all overloaded. I have already asked a few times how the heating curve is set. We have a heating system of the brand NOVELAN.