You may need to reset a Powered Room Thermostat if you are swapping which Genius Hub device is included onto, or if you are trying to clear some of the error codes.
To factory reset a Powered Room Thermostat:
When rES is no longer displayed, the device is factory reset.
The Powered Room Thermostat is now factory reset to a default state, to add it back onto the system again go to the 'Doctor' on the app which is under the 'Main Menu'.
For more information see this article.