The most likely cause is a jammed or overloaded front caster wheel. Hair and debris wrap around the axle, preventing it from spinning freely.
- Turn the robot over. Pull firmly on the front wheel module to remove it from the robot.
- Pull the wheel straight out of its housing.
- Remove all hair and debris from the wheel axle and the inside of the wheel cavity.
- Push the wheel back into the housing until it clicks into place. Reinstall the module.
If that didn't work, check the Edge-Sweeping Brush. Use a small screwdriver to loosen the screw, remove the brush, and clear any tangled hair or threads from its shaft. Reinstall and tighten the screw.
Heads up: A clogged front wheel that isn't spinning can damage your floor. If cleaning it doesn't fix the issue, contact iRobot Customer Care.