iRobot Roomba · updated 2026-07-06
Error 31: Internal communication error
What it means
An internal software communication error.
The fix
Press CLEAN to restart; reboot the robot if it persists.
Applies to
i and s Series (incl. S9)
Source
Official iRobot support article: https://homesupport.irobot.com/s/article/21048