The iPhone App gives you the ability to designate an active sensor during preset (by Nest) time periods. It also supposedly gives you the ability to change the sensor at least until the next time interval (9 PM, 7 AM, 11 AM, or 4 PM). So, if you want to be in a room with a sensor, but that's not on the usual schedule, you're supposed to be able to tell the thermostat to use the sensing device in that room for now. However, for at least the last month, whenever I do that, it will register the change and the heating system will respond. Then a short time later, sometimes less than 10 minutes, it reverts to the predesignated sensor. It's like the app is telling me that I don't know what I want. Any suggestions?