I replaced a builder-installed Honeywell T4 Pro (TH4210U2002) because it was too basic and lacked Wi-Fi/app capability. The Lyric T6 has been a very nice upgrade overall. It offers far more functionality, scheduling flexibility, and smart features, and installation was simple—almost plug-and-play since it used the same wall plate and wiring as the existing T4.
What keeps this from being a perfect experience is a persistent “Indoor temperature sensor error” message that appears on the thermostat display. There is little to no guidance in either the thermostat interface or the Resideo app explaining what this message means or how to clear it. The thermostat appears to function normally despite the warning, but seeing a constant error message on a new device is frustrating and undermines confidence.
Also worth noting: the utility rebate process tied to this model can be more complicated than expected and may be difficult to get approved depending on your energy provider.
Overall, I like the T6 and its capabilities, but clearer error messaging and better support documentation would significantly improve the user experience.
It is smart but missing features from competitors. There is no schedule for circulation fan, either on or off. I can't create customize temperature schedule. There is no Heat+Cool mode. Either Heat or Cool. The runtime usage has one day lag to display data.