Heating settings as well as room temperature measurement

Good day,

we have received a new heating system. Model Buderus Logamax. Due to various circumstances (illness, corona pandemic, etc.), I unfortunately did not receive any instructions. Maybe someone here can help?

In the menu under "Heizung," there are the options "Heizen" and "Absenken" with a temperature behind them (currently set to 22°C Heizen and 15°C Absenken).

An outdoor temperature sensor is apparently installed because this value is displayed in the info menu. For example, today 15.5°C. There apparently is no room temperature sensor. This value is not displayed.

Now I wonder: How does the heating system detect the room temperature? Because if I understood correctly, I set the desired room temperature for day (heating from 6 a.m.) and night (lowering from 11 p.m.) with "Heizen" and "Absenken," right? But how does the heating system know when this value is reached? The radiators do not get really warm either. At most lukewarm. All have been bled. With the old oil heating system, they got very hot.

Regards
deep

Gas or oil?

It does not matter at first how warm the radiators are; what matters is whether the room reaches its desired temperature.

Otherwise, the "detection" is done by the heating curve and possibly by the return or flow temperature.

The new heating system is gas

The heating system detects this via the return flow, that is, how much the water cooling down returning compared to what goes into the room.
Heating curve is probably set incorrectly.

Then the heating system does not recognize the room temperature at all in that sense.

It regulates based on the outside temperature and the set heating curve.

Has a hydraulic balancing been carried out?

A thermal balancing is then done by you.

The heating detects this via the return flow, that is, how much the water returning cools down compared to what goes into the room. The heating curve is probably set incorrectly.

That would be unusual; most heaters with outdoor temperature controllers operate solely based on the heating curve, outdoor temperature, and flow temperature.