Properly setting the air-to-water heat pump with underfloor heating

I do not know it, but I assume that the display indicates from which pressure difference it opens, so increase the pressure

Do not complain about the service providers. The best they can do is to set a calculation as the default setting. Everything else will happen later.

Isn't the heating load calculation a bit strange to you? I mean, if I compare the bathroom and the bedroom... They should have definitely laid a few more meters in the bathroom!

So, the technician was here today! What was done? - Parallel shift +2 degrees (bathroom too cold) - Pump from 60% to 80% (flow rate too low) - Temperature difference from 7 to 5 (no idea) - Timer switch for circulation pump installed - Hot water from 50 degrees to 48 degrees I am now waiting for the heat pump to start so I can see the flow rate. My black box is a bypass valve. When the ERR are disconnected, it can be set to 500 mBar. If not, it should be set to 250-300 mBar, something about defrosting the outdoor unit. So, in my opinion, a "proper" hydraulic balancing was not carried out; it was only checked manually whether the return flow is cooler than the supply flow. Let's see how the temperature develops in the bathroom now; otherwise, I could still install a heating element in the towel radiator.

About the bypass valve and defrosting. For defrosting, the heat circuit is reversed. This uses the heat of the screed to de-ice. Furthermore, a minimum flow is required. To guarantee this, there is the bypass valve, which opens when too many heating circuits are closed. If all heating circuits remain open (deactivated ERR), you can set it to maximum. There is no fully closed position; it only opens at a higher pressure difference between flow and return. With a well-designed heat sink (= underfloor heating), it is practically closed. No thermal short circuit during heating and defrosting.

Yes, that's what he told me too and I shortened it a bit! My flow is now definitely >2l everywhere. So I’ll fiddle around with it for now!