Hello Anton,
yes, I have implemented the solution with the Stiebel LWZ8.
It has a solar connection and controls a circulation pump for the buffer tank depending on the temperature of the sensor at the top of the buffer tank.
I have been running the screed heating program since mid-February and have heavily used the stove in the process. Around 700kWh have already transferred from the buffer to the Stiebel alone. That is about 240 euros less in electricity costs for operating the heating element.
For example, with the Stiebel, you can also set the domestic hot water temperature slightly higher when operating with solar. Or better, you set the domestic hot water preparation to the times of day when the buffer has temperature.
I recommend you download and study the operating manual as well as the commissioning instructions for the Stiebel as a pdf from the Stiebel website. That makes you smarter than any opinion on the internet.
There is a strict opinion circulating on the internet that the low-temperature system of an air-water heat pump is technically and economically not sensibly compatible with the high-temperature system of a water-bearing wood stove anyway.
That may be true for heat pumps without a solar connection.
I, for one, am convinced that with my system at AT from down to -5°, I can get through the night with no more than 5kWh electricity consumption if I fire the stove in the evening with 10-15kg of beech.
My 27kWp photovoltaic system delivers between 1.5-2.5 kW during a cloudy winter day. That is enough to heat.
If you have further questions, just get in touch.
Regards Gaucho