Yes, I have already gained some initial experience with it. My system has been running since 8/18. After the outside temperature dropped accordingly, the Bien-Zenker has been running all day long (77 starts since then). In summer, I couldn’t use much heat.
I have now received my first electricity bill and consumed more than 1000 kWh less electricity and got money refunded.
The gas bill is still outstanding. The heating system itself is very sensitive compared to my Eurola from 1998. That means, after the hydraulic balancing, initially almost no heat or hardly any heat reached one room. But we have managed to fix this by now. However, I had to completely relearn with regard to the valve control on the radiators.
Customer support from Viessmann is more than poor, but I am not used to it being any different.
The APP for "control" can at best be described as poor. It constantly crashes and only provides access to the temperature and switching times of the heating/hot water preparation. The fuel cell or the energy produced is not visible.
Initial technical defects in electricity meters and errors on the BUS are not problematic. Spare parts are still not available after 8 weeks!
So far, however, I am satisfied.
Regards Heiko