This product would not link took customer Daniel Ichim multiple phone calls to get a case I'd number & the last call the service team went through linking it with him which took 20mins then after it failed said I'll have to speak to my supervisor disappeared for another 15mins eventually came back & told my customer she could not find her supervisor & that she would ring him back , well he's still waiting? In the meantime I the installer (Stephen Dove)have purchased another nest stat & replaced it which linked first time. So I'm out of pocket because I've had to make a second trip to the job which isn't local to myself. All in all not a good experience. There must be better technical helpline put in place.