This is the port of the ST Nexia Thermostat Manager with the added capability of using the American Standard login. It has been tested with XL850 and the XL824 thermostats, but may also support other devices. The solution requires the app:
https://raw.githubusercontent.com/thebearmay/hubitat/main/STPorts/nexiaThermMgr.groovy
and the driver:
https://raw.githubusercontent.com/thebearmay/hubitat/main/STPorts/nexiaThermostat.groovy
These can be imported manually or via HPM.
Related thread: