The idea of when we leave the house heating turns down, and then turns up again as we return seems a good idea when taking loads of caravan holidays, where our time away is not fixed, weather turns bad we return home, having a good time and we extend. A Energenie MIH0014 3 kW Remote and App Controlled Relay costs around £22 I already have the hub, and remote controls all I would need is a plastic box to mount it in. So cost is low, but how well does the phone app work is the question. I assume you would be able to program in more than one phone? So if either my wife or I approach home it turns on, likely would need 70 miles radius, average of 35 MPH means turns on two hours from arriving at home, we could one also hopes over ride it when we are on motorway, or camping within the radius. However this is the point, I don't know, I have never tried geofencing. Other option is more Energenie MIH0013 TRV heads, although kitchen and hall would remain warm so stopping house from freezing, fitting these to bedrooms as well as living and dining room where already fitted, we could turn down rooms to 16 degs C while away. Third option is Nest which can be linked to Energenie MIH0013 TRV heads with follow command, and use the geofencing with Nest. Energenie MIH0014 is cheapest option, but questions, I have MIHO007 sockets, and any power cut and they auto switch off, I set timers to switch off/on so at those times they would switch on again, but a power cut of 2 minutes would mean using the Energenie MIH0014 the heating would remain off, could a by-pass switch be fitted, or would it detect phone within range and turn it back on anyway? My idea is the Energenie MIH0014 would replace the central heating programmer. I can still set on/off times 3 a day, and select which days of the week these are valid for, and using the three existing remote controls and the button on the Energenie MIH0014 over ride it. Or use phone, tablets or computer. It all looks OK, but would like to hear from anyone who has used geofencing as to how well it works first.