After reading through the manual, I have made myself to the assembly. After a few minutes I noticed that the Rondostat does not fit on my valve. The instructions are too scarce respect. The various valve types. And, the illustrations of the valves are much too small for the included adapter, so you do not really recognize what.
After some research on the internet I have found that the radiators have a Oventrop M30x1 fine thread valve. The Rondostat contrast, a M30x1,5 thread. Here a corresponding note in the instructions should have been that there are also various M30 thread for radiators. The unfortunately this was not the case, I was already on the verge return the Rondostat because it does not fit. Luckily I was able to get an adapter at Conrad.
Installation from Rondostat with the adapter runs smoothly. However, I then found that the heater was not completely cold, the valve was therefore not completely closed. A bit of WD40 on the tip of the valve and reciprocate with the tongs solved this problem.
