Underfloor heating on the upper floor - one room always remains too cold

yellow = office (10sqm) TARGET = 20, ACTUAL = 22.2 green = bedroom (17sqm) = TARGET = 21.5, ACTUAL = 21.5 red = child 1 (17sqm) = TARGET = 21.5, ACTUAL = 19.9! purple = child 2 (12sqm) = TARGET = 21.5, ACTUAL = 21.5 blue = bathroom (12sqm) = TARGET = 22, ACTUAL = 21.9 Thermal balancing done 2 weeks ago, I had a friendly heating technician over. Since there was no result, reset to factory settings. I also don’t understand why heating circuit 2 in the bedroom is usually closed and only heating circuit 1 is running. Also, the KNX shows the actuator of the office as closed although the motor is open in the heating circuit distributor. *Edit The heating pump is running at full power (40W).

I have become a bit alert now that you wrote KNX. Are you sure that it doesn't turn off in between? Night setback or something like that? And above all, how do you measure the temperatures? With my KNX sensors, the deviations were very high. Compare that with an external thermometer. And please check that the flow display is not simply stuck.

Note the green taco setters. One open, one closed? They should receive the signal from a thermometer and always move together. What’s the point if there are two heating circuits in a room and one compensates for the other?

Then for the children's room, if everything is wired correctly "as I saw it in the bedroom someone made a mistake" an undersupply of the flow can occur if the heating pumps are undersized. So please set all actuators permanently to open or remove them and perform the hydraulic balancing again.

I have become a bit suspicious now that you wrote KNX. Are you sure it doesn’t close in between? Night setback or something like that? And above all, how do you measure the temperatures? With my KNX sensors, the deviations were very high. Compare that with an external thermometer. And please check that the flow indicator is not simply stuck.

No, they are open continuously. I was definitely at the heating circuit distributor about 20 times in 3 hours, it was always open, or I manually set it to "open" for two days so that they wouldn't close. The temperatures are measured by the SMT glass push buttons in the rooms, which hang at a height of 1.5m. Comparison with an external thermometer also showed no significant deviations (<0.5 degrees).

Note the green taco setter. One open, one closed? They should receive the signal from a thermometer and always move together. What use is it if there are two heating circuits in one room when the other compensates it.

Yes, I had already mentioned that. It doesn't make sense to me. I have assigned the electrician to it.
But it was not about green at the beginning, rather about red. Continuous flow and yet only just under 20 degrees.
All actuators had already been manually opened for days and it is getting warmer everywhere, just not in the red circuit.

I will now bring this to our expert and put it on the list of defects. I'm really getting annoyed by this. My time didn't just fall from the sky either.

*Edit:
The heater can currently make excuses because it was planned with standard temperatures and I am not running those.
Sure, at 35 supply I throttle 22 out of 23 heating circuits. Bravo.

No, they stay open constantly. I was definitely at the heating circuit distributor about 20 times in 3 hours, it was always open or I manually set it to "open" for two days so they wouldn’t close.

And if you close them via KNX, does the flow indicator change (to zero)?
Or does it stay there?

The temperatures are measured by the SMT glass switches in the rooms, which hang at 1.5m height. A comparison with an external thermometer also showed no significant deviations (<0.5 degrees).

I suspect you mean not SMT but MDT?
That exact gauge I have installed at my place.
Sometimes they need a 1-degree correction!
So measure again with an accurate thermometer.

I will now bring this to our heating technician and put it on the list of defects. I’m really getting annoyed by this. My time didn’t just fall from the sky either.

*Edit:
The heating technician can currently excuse himself because it was planned with standard temperatures and I’m not running those.
Sure, at 35 supply temperature I throttle 22 of 23 heating circuits. Bravo…

You won’t have any chance with an expert if you don’t raise the supply temperature and show that it still doesn’t get warm...

Basically, I have the feeling you’re looking here for that one, all-solving answer.
But thermal balancing is diligent work over several weeks.
So proceed as follows:
- Calibrate all thermometers or use accurate external ones
- Make sure the Taco setters display correctly
- Disconnect the KNX control or set all actuators to permanently on
- Then start throttling the room that is too warm a bit
- Do this until the temperatures are right everywhere.

What’s already noticeable is that the smaller purple room has more flow than the significantly larger red one.
That can’t be right.