Have only a first thermostat ordered because I am a layman and Electrical hardly have a clue. The connection was easy, but it should be noted that there are three wires needed here. The old thermostats were only Two Wire, but as for me basically five-core cables have no no problem. A little Umklemen the manifold and everything works great. Operation is also extremely easy. The first time no longer be needed the beiligende manual, but after that. Nice that you can define multiple start and stop times per day, so it is possible the heating for example to turn on in the morning, during working hours back down to drive and to go after work back to heating mode. The optics are against my old mechanical thermostats Surface course Hammer: D The backlight can be had, contrary to what the other raters also permanently on (extended menu). After I was fully satisfied, I have now changed all room thermostats in the home. Fully recommended!