It looks like you're new here. If you want to get involved, click one of these buttons!
I've had a total of 3 ecobee Smart Si units. The first one works great, no need to talk about it.
The 2nd one was giving me wildly erratic temperature readings. Even playing with the offset, I would get erratic numbers. By comparison, my old OEM thermostat sitting right next to the ecobee would consistently show the correct temperature while the ecobee would show anywhere from +2 to +9 degrees off. It's the summer, so not sure what it would do in the wintertime, my guess is the same in reverse. If my OEM thermostat showed "68 degrees", the ecobee mounted right next to the OEM unit would show anything from "72" to "75" degrees. I'd have the Cool setting set to "70 degrees" and the ecobee would be cranking all day long trying to get there, always stuck between 72-75 degrees and meanwhile it's freezing in my house at 66 degrees.
I exchanged this unit for another unit with ecobee.
Same exact problem on the 3rd unit.
So, I don't know what to make of this. Do I have the equpment selected wrong? Would that make a difference? What would be causing this? My only guess is it's defective.