So I got a two pack of ecobee sensors yesterday, it is a good idea but don't work the best as it averages out the temperatures and prioritizes the room you are in. So as I was downstairs it was warmer and the heat did not kick in making the temperatures upstairs drop slightly but more in my room as no heat was running. I usually keep my heat at 21.5 but the temperature in my room was 20, so when occupied the furnace had to run long and hard to get it up to 21.5. As I prioritize that room it keep that room at 21.5 while the rest of the house was hot. But as it averages out on the main thermostat it will read a wrong, 21 as you can see. I had my other thermostat above and it was 24 degrees.. while in my room was 22 because it overshot. Don't recommend them. The ecobee thermostat itself is great with a proper set schedule, do not use these sensors.

Product will not mount on the wall using the supplied wall mount. This failure turns a great idea into a waste of money

There is a firmware issue causing these not to pair with some older thermostat models. Ecobee has known of this issue for at least 10 months and is still only "colleting data". Meaning they are not actively prioritizing or developing a solution. If your thermostat is running an older version of firmware, do not buy. You will likely spend a ton of time troubleshooting only to be told it's a firmware issue. An honest company would note this on the product page to prevent customers the headache.

Way ways to expensive and not worth buying. The technology is old and should be using mmave at this point!!!!!