new heat pump as a replacement for oil heating with existing radiators

Did you find the settings for the heating curve? What is currently set there?

I didn’t manage today, will be tomorrow. Thanks, tireless helper!

mixed with the boiler water

In the heating circuit for the practice (the one with the mixer) I have no problems. My daughter heats very consciously and never more than necessary. Son-in-law controls everything via WLAN and corresponding valves. For the apartment, I have avoided such effort so far.

Well, it’s happening after all. Thumbs up for that. You are now taking the right step. The system is still running, you can find out the lowest flow temperature. Please familiarize yourself with the thermal balancing. You can still get a lot out of it. If you deal with it now, you can have a [PASSENDE] heat pump installed in the spring. Then you would have achieved something sustainable for your family and increased the value of your property. Please don’t lose patience.

A quick question for the heat pump experts. Are there heat pumps with two heating circuits, HT and NT, for a combination of radiators and underfloor heating in the house? With gas boilers, this does exist.

That exists with gas boilers.

At least with the major German manufacturers, nothing has changed in that regard. Behind the burner or the hydraulic station, it does not matter how the heat was generated. The heating circuit with the higher flow temperature is then unmixed; in the other, its own return flow is mixed in. This requires an additional pump group with a mixer and circulation pump. The control is basically the same as with the burner as well.

A quick question for the heat pump experts. Are there heat pumps with two heating circuits? HT and LT for a combination of radiators and underfloor heating in the house?
With gas boilers, this is possible.

Yes, you can do that. Or you can simply have one circuit if the temperature difference for underfloor heating and radiators is not that large. It can then be operated with an average temperature and accordingly adjusted hydraulics. You may then possibly forgo additional pumps, mixers, buffers, valves & co.
But yes, two circuits are also quite feasible.

The heating circuit with the higher supply temperature is then unmixed, the other one has its own return mixed in. This then requires a pump group with a mixer and a circulation pump in addition. The control is basically the same as with the burner.

So I then have the heat pump completely in the high temperature range and not such a good annual performance factor. Thanks for the feedback.