Incorrectly adjusted heating system - a case for warranty in new construction?

Especially since the OP still assumes his consumption is too high. Because you can heat 950sqm with 6 tons of pellets. If I were to go after anyone, it would be the one who put this idea in my head. Meanwhile, I am interested in whether the OP is (co-)owner of the apartment building or just rents.

1. AFAIK, you can usually only set a target flow temperature or a maximum flow temperature. The actual flow temperature cannot be specified but follows the control depending on the outside temperature and the settings on the thermostat.

2. Yes, usually the company owes not only the installation of a heating system but also its functionality, which naturally requires the correct settings. A window that is not properly adjusted would be equally defective and will, of course, be reworked. However, it always depends on what was agreed upon!

3. I find a flow temperature of 50 °C unusually high; which modern heating systems operate at that level? Something is wrong here.

Incidentally, the OP is stingy with information; at least he could have revealed the type of heating system (I find transfer of information from other threads difficult ...).

Fire does not exist in cold. Corresponding heaters heat water and then mix it down to the required temperature. If the supply line were too hot, the living rooms would be too warm even with the room thermostat set low. Is that the case?

@ OP have the heating engineer explain the background to you.
You should not arbitrarily lower the flow temperature on a heating system that, due to its principle, requires its operating temperature.
This causes the boiler to constantly turn on and off and not run continuously.
As a result, the lifespan of the burner decreases and the efficiency of the system drops.
I estimate the max flow temperature is set to a max of 55°C on your system.
Personally, I would not lower the max flow temperature on your system to less than 45°C.

Fire doesn't exist in cold. Corresponding heaters heat water and then mix it down to the required temperature.

Maybe it's my reading comprehension, but the opening post mentioned neither the type of heating system nor specified the temperature in more detail -- supply to the underfloor heating or output from the heat generator, both would be possible, with "Vorlauf" meaning the former to me. And an underfloor heating system with 50 °C is rather unusual.

I am fundamentally interested in the topic, but it's pointless to speculate based on incomplete information (is a valve stuck?).

Here, the only advice was indeed to contact the heating engineer, and the responses also pointed in that direction. Perhaps the OP will let us know what they end up doing and what comes of it.

see here: