Underfloor heating flow temperature 20 degrees? Return temperature? Solar support?

Hello. Maybe someone can give me some advice. My new underfloor heating raises some questions. -Flow temperature only 20 degrees??? Kfw70 new building with solar support. Return flow also 20 degrees? The surface temperature (laminate) is between 23 and 21 degrees! The heat meter shows consumption. The thermostat controllers are set to 20 degrees. -A glass tube in the distribution box appears as if it contains no water. All the others show a water level! Allegedly a balancing was done for acceptance. According to the installer, the heating should be adjusted. Apparently, I don't need to do anything. Just regulate via room thermostat... I am at a loss...

The flow temperature should depend on the outside temperature. The colder it gets, the higher the heating curve goes. In my opinion, all your little tubes are turned up to the maximum, as the float is at the top everywhere.

Doesn't that mean that the circles are closed?

That makes sense to me. The set temperature is 20 degrees, the room is above 20 degrees (otherwise the floor wouldn’t be above 20 degrees), so the RTR turns "closed," meaning the tubes indicate "closed." There is no need for heating, so the supply line stays somewhere near room temperature.

UPS sorry.... yes of course flow rate is everywhere at 0.0. For testing, turn all room thermostats fully up, then the floats should go down after a short time.

UPS sorry.... yes of course the flow rate is showing 0.0 everywhere. For testing, turn all room thermostats fully up, then the floats should go down after a short time.

Thanks for your tip!

Am I understanding the underfloor heating correctly? This is my first...

So if I set the room thermostats above 20 degrees (then a light turns on), the flow temperature must increase. The liquid in the tubes must then go down so that the float lowers. The more I turn up the room thermostat, the more the float sinks because it indicates the flow rate.

How can I test whether the balancing has been set correctly? I received a tip (not tried yet) to turn all thermostats fully up and measure the room temperature. If this seems too high to me, throttle back the heating circuit of that room a little. Test every room like this... And then set all room thermostats to zero...

Best regards