Bought a house with @honeywell network-enabled thermostats. In order for me to control them, the previous owner has to unregister them. There isn’t a way from the device to unregister it. Seems like Honeywell missed a common use-case and made it far harder than it should be.

Hi Bil, we will be happy to assist you unregistering your thermostat from the previous owner. Please feel free to send us a DM with a picture of the screen of the thermostat and a picture of the back of the face plate showing the MAC ID and model number. - Maria