Air-to-water heat pump sizing in new construction

Ah, he is supposed to do the comparison with the room valves fully open and you want to have the protocols!

Can this requirement really be made or are there possibly also legally regulated regulations regarding the "valve position"?

The valves are adjusted during the hydraulic balancing so that the previously calculated flows are achieved with fully opened actuators. This is the basic setting. Then, in the following heating periods, the thermal balancing takes place. Here, the flows are adjusted again according to the difference between the actual and desired room temperature. The actuators of the ERR partially interfere significantly with this system in underfloor heating. This is especially relevant at targeted low flow temperatures and in the case of heat pumps, this sometimes/often leads to cycling systems with rapid wear and premature failure of the compressor.

Our device is here. :)

Unfortunately not yet connected, because the electrician and the heating engineer were not allowed into the basement. The tilers had been working alternately in the hallway and the utility room.

Our device has arrived. :)

The same little darling was installed at our place a few days ago and fully connected today :)
The electrician especially "raved" about the cooling function or at least highlighted it positively, saying that he is very satisfied with his own at home.

We probably won't need the latter in the coming months, but now winter can come :)
I am curious.

The electrician had especially "raved" about the cooling function or at least highlighted positively that he is very satisfied with his at home.

Today I happened to have a conversation with one of the neighbors who has an identical system. When asked about the cooling function and his experience, he said that the cooling function has not yet been activated. The installer said that this may only be activated after the warranty period has expired!?!?!? I could only raise my eyebrows.... man oh man.

The installer said that these may only be activated after the warranty expires!?!?!?

He must have confused that with the self-destruct mechanism... ;-) No, seriously: Every owner of such a system should definitely make sure to learn how to change EVERY setting themselves. Whether one actually does it or not is another matter. But eventually the system gets old, and no one can guarantee that the active service technicians will still have a way to get the installer access running. Therefore, you should keep pestering the manufacturer until you get the installer access. Sometimes the codes for it can also be found online.