Air-water heat pump combined with underfloor heating does not work properly

Our technician told me that I should turn down the volume flow in the rooms where it should get colder and increase the volume flow where it should get warmer.

Our technician told me that I should turn down the volume flow in the rooms where it should get colder and increase the volume flow where it should get warmer.

Well... something along those lines. Look up Thermal Balancing.

Whether you need to train as a heating expert is up to each individual, but you should at least read up a bit on the basic principle.

The energy source has nothing to do with the problem that you can't get large temperature differences in different rooms in a new building.
There are some things to be aware of in a new build or underfloor heating (usually the effect is stronger the better the insulation standard).

Temperature differences in the rooms. Depending on the constellation, you can achieve some difference. But since the interior walls are usually not insulated and thus offer little resistance to heat, you always end up heating the neighboring room as well (or the one below or above). A classic example is a bathroom next to a bedroom. Bathroom set to 24 degrees, bedroom set to 18 degrees. The bathroom doesn't reach 24, but the bedroom reaches 21. Flow in the bedroom turned down, flow in the bathroom fully on.
Now some might say that this worked in their old house. Yes, that may be, but that’s because more heat was lost through the exterior walls/windows, so this loss outweighed the heat gain through the interior wall.

Inertia. Underfloor heating is sluggish. Especially when combined with good insulation and low flow temperatures.
So if the room is too warm and I think I’ll turn down the thermostat to cool it briefly, I might only notice the effect the next day. Why? Good insulation retains heat in the room, and the heat in the screed remains relatively long.

If you want a lower temperature in one room than in another, yes, then you should adjust the flow rates. But keep in mind that with the new building/underfloor heating constellation, this is only possible to a limited extent.

Edit: This is by far not complete and simplified. In detail, there are often more factors that additionally come into play.

Thank you again for all your tips. I read into the topic a bit last night and came across the following product. The Homematic IP underfloor heating actuator seems to control everything automatically or takes over the manual adjustment and thermal balancing. Does anyone of you know it or can assess whether it makes sense?

Do you have the lengths of the heating coils and the heating load of the individual rooms? There are calculators or formulas on the internet that you can use to calculate the (rough) flow rates. Then you can roughly check whether the Homeatic is working correctly.

Thanks again for all your hints. Yesterday evening I read up a bit on the topic and came across the following product. The Homematic IP underfloor heating actuator seems to control everything automatically or takes over manual settings and the thermal balancing. Does anyone of you know it or can judge if it makes sense?

I know the company, we had the radiators in our old apartment equipped with wireless thermostats from them. That worked quite well.
I cannot judge how the heating actuator works. I haven’t read it in detail, only saw something about stepless flow control. To achieve that you’d either need actuators that can do that (rather rare) or the actuator controls it via something like pulse control. No idea, I’m not technically familiar with the details.
The question is: Do you need that?
To make the whole thing controllable you usually need an access point with Homematic. So you’re spending another 300-400€ on devices that consume power and can break down. Thermal balancing is no big deal. It will cost you a bit of time during one winter, but that’s it. If you do it right, you’ll never have to touch your room thermostats again.

I have KNX installed. I integrated the actuators into KNX (it just happened this way for different reasons, not because I said I needed it). So I could program every crap there. Like when the third full moon of the year, more than 4 hours of sunshine before 4 PM and more than 1.5 m/s wind from the southwest, the temperature in the living room will be raised by 0.5 degrees, but only if someone is present.
And you want to know what I did? One winter season of thermal balancing. All actuators are always fully open, the rest regulates itself. Maybe I have to fine-tune a bit this winter (second season in the house). But so far totally trouble-free. Now that it got cooler, the heat pump started by itself and lo and behold, the temperatures are +/- 0.3 degrees as I balanced them last season.

Yes, there are indeed a few details. When the sun shines a lot, it’s very windy, etc. But you can’t regulate that because the system is too slow for that.

I am surprised every time as a layperson that you apparently have to have studied in order to operate an air-to-water heat pump (-:

If I had known that, I would have gone with gas, the 10 euros more per month would have been worth it to me so that I could just have peace and now also just turn it up during the transition period…. I am a woman and it is practically unbearable that the heating does not come on because of some hysterics blah blah (my husband says) … On the ground floor I turn on the stove, in the bathroom I am freezing (-: Women, you know….