If a room already has an ecobee or Honeywell T9/T10 smart thermostat, there is no need for a Puck in that room. Flair will use the temperature data from your thermostat as if it were a Puck.
If you connected your Works with Nest and Flair accounts before August 31, 2019, you will not need a Puck in the room with your Google Nest thermostat. After August 31, 2019, you will need a Puck in the room with your Google Nest thermostat. For more information, see our article on how Flair works with Nest after the Google transition.