Geothermal heat pump single-family house 200m² underfloor heating kfw55 - setting/optimization

I would still appreciate an answer to the question of whether it makes sense, for example in the bedroom, to open the valve slightly. Currently, it is still closed and at about 20 degrees in there, I find it rather too warm. With even more intensive ventilation, we might be able to maintain 19 or at least 19.5 degrees, but I wouldn’t know why I should create a small flow here?

And a completely different question. The heat meters built into such devices, are they standardized, calibrated, tested? If I assume that these values are correct, then during summer (i.e. for hot water) I reach a COP of about 4, and now during the heating + hot water phase over 6. Overall, since the start in May, I am at a COP of 5.4 with a tendency to rise quickly. Is this due to manufacturers’ optimistically measured heat quantities or is this realistic?

Better values in winter are normal, as only hot water is produced in summer (short cycles, high temperature difference).

Whether your values are correct often depends on whether the electricity meter also counts the pump power, controller, etc.

If you achieve a COP of over 4 with a brine heat pump over the course of a year, that is already good.

Whether your values are correct very often depends on whether the electricity meter also counts the pump current, controller, etc.

That would be my next question. The meter is a secondary meter (with special heat pump electricity and thus blocking times) "only for the heat pump." Some heating components, however, run on household electricity. For example, the heating pump. The heat pump itself is also connected to household electricity. This means that in summer only consumption for the compressor and primary pump, i.e. for hot water preparation, is counted. Passive cooling, heating pump (e.g., for flushing when cooling is off) is not. Although there is a separate fuse/RCCB at the household meter, I do not have a separate submeter for the heat pump. Should these consumers be "included" for a realistic consideration of the COP, or are they excluded? But this means that the heat quantity meters in these heat pumps can be trusted, or are they exaggerated? Should they be remeasured for realistic calculations? If yes, how?

Would these consumers have to be "priced in" for a realistic consideration of the COP...

Yes
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If you achieve a COP of over 4 with a brine heat pump over the course of a year, that is already good.

I can't quite believe that now: our heating is probably not super optimized because I somehow lack the motivation due to the ridiculously low consumption. Nevertheless, since commissioning, we have had a COP of 4.2 for hot water, 5.9 for heating, and 5.6 mixed.