Hydraulic balancing air-water heat pump + efficiency circulation pump

If all the circles are closed as mentioned, more than half of the water volume is missing, then you have a different hydraulics.

Before you test more things, I would first continue as planned.
So throttle the rooms so that you have the desired temperature everywhere.

If you have a 2 K differential at 900 mbar, increasing the volume flow won’t help much anymore because the differential will decrease even further.

More flow rate than the 749 l/h apparently cannot be achieved with the hydraulics. Yes, that is probably true, I will start throttling today. I can't go any lower with the heating curve, so throttling is the only option left. I will then throttle the hallway, guest room, and possibly the bedroom today.

Is the bathroom still too warm? Then first lower the desired temperature before throttling. This way you change the heating curve again. And only throttle one room/heating circuit at a time, then wait again.

Almost all rooms had at least 20.0 - 20.8°C this morning

Living room, dining room, kitchen 21°C fully open
Hallway 20.8°C fully open
Guest room 20.3°C fully open
Bedroom 19°C fully open
Bathroom 20.4°C fully open
Utility room 20°C (is throttled)
Guest WC 19.7°C (is throttled)

The consideration would be either to increase the curve from 0.10 to 0.15 so that the bathroom reaches 21°C just to be safe and then throttle the rest again.

Or should I better increase the slope?
In theory, I would even have to go to 0.15 because the underfloor heating is designed for 30° flow temperature at -12°C... But theory and practice...
Attached is the original Vaillant heating curve
[ATTACH alt="Heizkurve-Header.png" type="full"]56026[/ATTACH]

I would leave the curve as it is below, and if the bathroom fits like that, throttle it.
In addition, record daily consumption and flow temperature in comparison to the outside temperature.
It's not just about the values but also about an efficient heating system.
Observe and wait for now.

Okay, let's try it