Error 4 Moderate Easy DIY

Roborock Robot Vacuum Error 4 — Cliff sensor dirty or robot on dark surface

Roborock Robot Vacuum · Error code Error 4

What Error 4 Means

The downward-facing cliff sensors detect what they think is a drop-off. Caused by dirty sensors, very dark flooring, or actual stairs.

Symptoms

  • Voice prompt 'Cliff sensors are dirty, please wipe them'
  • App shows Error 4
  • Robot stops at black rugs or dark floors
  • Robot stops near stairs

Common Causes

1
Dust or smudges on cliff sensor lenses

Sensors on the underside collect dust, dulling reflections.

2
Very dark or black floor/rug

Dark surfaces absorb IR; sensor reads as no floor.

3
Reflective/glossy floor

Highly reflective surfaces can confuse the IR sensor.

4
Robot near an actual drop

Working as intended — stop before falling.

5
Sensor failure

Faulty IR LED or receiver in a cliff sensor.

How to Fix It

  1. Flip the robot upside down.
  2. Locate the small black/clear lenses around the front and side edges (cliff sensors).
  3. Wipe each lens with a dry microfiber cloth, then a slightly damp cloth, then dry again.
  4. Place the robot on a normal, well-lit floor away from stairs.
  5. Cover very dark rugs during cleaning or use the app's no-go zones around them.
  6. Restart cleaning. If error persists on normal floor, contact support.

More Roborock Robot Vacuum Codes

Error 1 Error 1 — LDS laser distance sensor blocked or stuck Error 10 Error 10 — Filter blocked Error 11 Error 11 — Magnetic strip / no-go interference Error 12 Error 12 — Battery low, returning to dock Error 13 Error 13 — Charging error / contacts dirty Error 14 Error 14 — Battery error

All Roborock codes → All robot vacuum codes →

Verified against manufacturer documentation: global.roborock.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.