Air heat pump is not heating, but the hot water works

Then just wait for the winter first. If the outdoor unit freezes.

Exactly for this case, I had a chimney with a fireplace installed. I was briefly annoyed about the coal to be spent, but when I read something like this, it does make a bit more sense to spend the money.

I wish you a quick fault repair.

Check all settings. Are all summer settings turned off? Has the summer cassette (if installed) been replaced? What temperatures, heating times, etc. are set? If everything is okay, maybe adjust the heating curve. The operating manual states how to set it.

As already said, I do not think it is a matter of settings. The employee from Tecalor had accepted the system and made all the settings in my presence and also explained them to me. Then the sanitary worker was on site and could not get it running. Unfortunately, I exclude the possibility of it being a settings issue for myself.

The question I hoped to get answered is more in the direction of whether I can or should take action towards Tecalor or the sanitary company. I am not looking to start a legal dispute here. I just don’t want to be sitting in the cold house without heating in December and then hear, "Well, you should have put the people in default in writing, etc., etc. They would have had to provide you with temporary heating because of § 0815."

Just wait for the appointment on Monday first. If the technician doesn't find anything or can't do anything, there's still plenty of time to pull out the big guns if needed. You can then bring up the topic of a temporary heater if he indicates that he won't be successful today.

But is it normal for new buildings to be this cold? Because of residual moisture or something? We (apartment from the early 2000s) turned on the heating today, but more so to get rid of the dust smell than because it was really cold. It was still probably around 20 degrees everywhere.

I also find it a bit strange.. we didn't have to heat yet, in the bedrooms it was once 20° in the morning as the lowest temperature.

So, I'll put it this way, our specialist company that installed the system has no idea about the settings. Everything was done by the field service. I also once had a question and just got "Try that, I’m not doing it, or call xxx." When was the setting and acceptance carried out?