On July 27, 2020, I had a smart thermostat installed by ADT technician. Everything seemed to be working fine until October 27, 2020 the temperature dropped here in San Antonio, Texas so I turned on the heater but it only blew cold air. I had an AC person come and check my unit and they said the wires were not correct with the smart thermostat or it was not configured properly. I contacted ADT requesting the same technician that installed but I am assuming he was not available so they sent someone else that did not know much about the equipment and was not able to solve the problem. I called another AC company to come check and was informed the same information about the wiring or configuration. The two AC companies would not touch the smart thermostat because they did not install it and did not want to mess with it. ADT sent out another technician that was not able to solve the problem either and I had him put up my original thermostat since my heater was working fine prior to installing the smart thermostat. My complaint is the technicians sent to my home did not know much about the product you all are selling and in turn has cost me money to try to fix what was working fine prior to installation.