Robot vacuum shows E3 and stops, often near stairs or edges.

Safety: Turn the robot OFF and flip it over on a soft surface.

• 1. Clean cliff sensors:
  • Locate the downward-facing sensors along the front underside (usually 3–6 small dark windows).
  • Use a dry microfiber cloth or cotton swab to gently clean each sensor window.
  • Do not use liquids directly on the sensors.
• 2. Test on different flooring:
  • Move the robot to a light-colored, non-reflective hard floor.
  • Turn it ON and start a cleaning cycle to see if E3 clears.
• 3. Check for physical damage:
  • Inspect the sensor windows for cracks or deep scratches.
  • If a sensor is visibly damaged, it will likely need replacement.
• 4. Internal check (advanced):
  • Remove the bottom cover screws to access the cliff sensor board.
  • Verify the sensor board connector is firmly seated on the main control board.
• 5. When to replace:
  • If E3 persists after cleaning and relocation, replace the cliff sensor module or consult a technician.