Floor heating problem and question

Hi Everyone!

I rent a 3.5 room 150 square meter approx. 20-year-old apartment in a small town in Luzern canton Switzerland since this September and have a floor heating problem. The issue is the following:

There is only 1 thermostat in the apartment and it’s in the living room. I did not get any instructions from the owner, so I assumed that it controls the heating for the entire apartment. When i started heating in October, I set the thermostat to 24 degrees but the temperature did not rise above 21.5 degrees in the living room even after weeks and the other rooms were even colder. So i notified the landlord, who sent a technician, who opened the service door for the floor heating and turned all the knobs up a lot. He also told me that if this doesn’t solve the problem, just play with the knobs until i get the expected temperature in the rooms. Since this happened, i have 3 issues:

• There is a constant loud high-pitched noise that i can hear in the entire apartment and it is super annoying. I made a video, hope you can hear it. What do you think can cause this?
• Am i supposed to manually adjust these knobs at all? I thought i should only be controlling the thermostat in the living room, and that should take care of everything. But the reality is that in all other rooms the floor is ice cold, the thermometer shows 21.5 degrees but the air feels cold and humid (65-70%), so it’s possible that this temperature is only thanks to the neighbour’s heating. I took a picture of the heating manifolds; it seems only 2 of them are directly controlled by the thermostat.
• I also checked the heat meter and it shows 1.886 MWh energy usage between Sept 1 – Nov 21. Does this sound reasonable or do i need to worry, if i only started heating in mid October and tried to keep the apartment on 22-23 degrees max?

Thanks!