I have 2 Heat Pumps, and live in the very hot summer climate of Phoenix, AZ. So I purchased 2 T9 thermostats to update the systems to WiFi. Installation for the first one was pretty easy and I only needed some help with a couple of things from "Support". When I attempted to install the 2nd thermostat, I didn't recognize the wiring that appeared behind the cover of the existing thermostat. I happened to have had a maintenance appointment around that time and the serviceman told me that that was a "Communicating" thermostat and if I wanted to replace it with a WiFi enabled one, it too would have to be communicating. The only one, he said, that would accommodate my system is made by "Trane", the same as my heat pumps. So, grudgingly, I had to return my 2nd T9 thermostat. The one I did install is working perfectly, does what I want it to do and looks great on the wall. I also installed a sensor that came with the thermostat. Also, an easy installation and it too works as it should.
Check your system to see if it can use all of its features before you buy this product. It does not control multi-stage equipment. Also, the command strips on the back of the remotes aren't very strong, so your sensors may fall off the wall.