After the "predecessor" of another manufacturer flew repeatedly from the heating valve as a result of cheap Kunstoffmutter, I became aware of this thermostat with metal nut. Initially everything was great: large display, easy to program and quiet. In operation then somewhat sobering: The window to function would not start even in frost out of the so-called optimization function showed no discernible effect.. For 2 weeks, however, total failure time and again with an error message "E3". Multiple Re-assembling and greasing of the heating valve remained without effect, the "engine issue" seems to lie at the gear drive with frayed and bent teeth ... Definitely not a recommendation, at least I could with the beautiful metal nut now my old thermostat back safely mount .. ,
