Air-water heat pump current consumption and data

The air-water heat pump does produce 640mbar after all?!

Where does it say that? :D

No, according to the datasheet you can turn it down to 600. Heimeier Hydrolux DN 20.

Did you actually get an additional pump?

Doesn't look like it. The heat pump can also deliver the required volume flow with the readjustment.

The ERR must be deactivated and the overcurrent valve closed to the maximum. Only in this way do you ensure that all the heat produced by the heat pump ends up exclusively in the underfloor heating.

Regarding legionella protection. This is a very controversial and much-discussed topic. If you observe a few points, legionella do not play a role in single-family houses. The most important point is no dead pipes with standing water. Consequently, if a circulation is installed, it should be flushed at least once a day, 5 minutes is sufficient. Secondly, the hot water storage tank should be adapted to the needs and regularly completely renewed with fresh water. A 600l hot water storage tank for one person would, for example, be problematic. For a family, 200-300l is not a problem. Even better is, of course, a fresh water station. A legionella switch actually only makes sense if not only the storage tank is heated to over 60°C, but this temperature is simultaneously reached at all points in the system, so all hot water taps must also be opened at the same time. Otherwise, in the event of an infestation, only heat-resistant lines are selectively favored, and there are also studies on this. If you look at it closely, you need significantly more than 60 °C in the system. During my clinical work for over 10 years in a pulmonary department, which also manages the internal intensive care unit of the hospital, there was not a single case of legionella pneumonia among residents of a single-family house.

The ERR must be deactivated and the overcurrent valve closed as much as possible. Only in this way do you ensure that all the heat produced by the heat pump ends up exclusively in the underfloor heating.

At 4°C outside temperature, the pump ran at least throughout the night and the temperatures are roughly within the target range.

I’ll talk to the heating engineer about why only the valve with a 350 mbar setting range is installed. Until just before completely closed, you can clearly hear flow through the valve, and that can’t be intentional.

You can't hear anything from me. Volume turned all the way up.

until just before fully closed, you can hear a clear flow at the valve and that cannot be intended.

Yes, that is the sad reality. In my case, both the supply and return were throttled, and the bypass valve was set too slack, even when heating the screed with the heating rod.
I don’t even want to know how much extra electricity that cost me because the heating was mainly running in its own juice.

Never trust a heating engineer ;)

where does it say that? :D

Just google your pump. Under technical data you will find the pump volume flow and the residual delivery height in parentheses.

No, according to the data sheet you can close it down to 600. Heimeier Hydrolux DN 20.

But you have the "standard" Vaillant thing with up to 350 mbar?
However, that should be enough.
I think it just has to be higher than the circuit with the greatest resistance.
How long was your longest circuit again?

It doesn’t look like it. The heat pump can also deliver the required volume flow by readjustment.

What volume flow do you need according to the calculation and what is the pump achieving now?