For effective cleaning, Roomba® takes the time to clean along the edges of the room, including around chair legs and other furniture. If you prefer a quicker clean and do not require this level of precision, Edge Clean mode can be disabled. The default setting is “on”.
If this setting is disabled, Roomba® may not cover the entire floor. To change this setting, use the iRobot® HOME App and select 
Cleaning Preferences ➔ Edge Clean.
NOTE: Edge Clean Mode is exclusive to the Roomba 900 Series of robots.
