I sit for about 9 months, the Max heating control. I started with my office, which is outside my apartment. Since I am only the hour there, the control is just great by the iPhone. Lack comparative data from previous years, I can not confirm that the savings so happen, but if you only heats to 16h per week instead of always have to give so what, alas! As Eco-temperature I chose 17 degrees, as you can then quickly heat up again to about 20 degrees. Even at home I put Max! now a. There too comfortable control. Replacing the controller was pretty easy at various thermostats. I had to replace Zehnder, Danfoss and Oventrop. Only the Zehnder towel warmers were a bit difficult because you badly behind the cover and the cover rankommt mounted must be before you can mount the thermostat; it is larger than the hole to the valve. One must note: the controls are quite large. Approximately 2 cm longer and min. 1 cm "thicker" than the manual thermostats. I just runtergeregelt at a heating no place for this Brummer, there I have the heater - this heater is probably only theoretically necessary. Another thing you should be aware. I do not even know if that's good or bad now: the union nut with which the thermostat is mounted, is made of plastic, as well as the entire casing. My 2-year-old has been repeated to me the thermostat simply pried - ie broken from the mother. Because everything is plastic, the nut screwed you again, puts it on the bracket at the thermostat and screwed everything turn again - goes without tools. No harm happens. Meanwhile, my son has (hopefully forever) figured that he "fix" is not the thermostat. Despite a slightly smaller thermostat module would be better, because not easily pry. Still, the idea is great, the Internet control works well, the design is absolutely first class. If it still an actual Themperaturfühler would ... would be great for my office. At home I look at the thermometer.