Roborock Robot Vacuum Error 4 — What It Means & How to Fix It
Roborock Error 4 is a cliff sensor error — the downward-facing sensors are dirty or the robot is sitting at a drop.
What this code means
In the Q5 manual the entry is "Cliff sensor error. Clean cliff sensors, move robot away from drops and restart." The cliff sensors stop the robot going down stairs. The manual also notes that after any sensor error you should clean the sensor and retry.
Taken from the Errors table in Roborock's Q5 user manual. Roborock reuses these low numbers across many models, but the lists are not identical — higher numbers in particular differ — so check the manual for your robot.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Dust on the cliff sensor windows | Very common | Yes — dry cloth |
| Robot stopped at the top of stairs or on a ledge | Common | Yes — no tools |
What you can try yourself
- Move the robot away from any stairs or drops.
- Turn it over and wipe the cliff sensors on the underside with a soft, dry cloth.
- Set it on level floor and restart.
When to call a technician
- The error persists on flat floor with clean sensors.
- A sensor window is cracked or missing.
Typical professional repair cost: Free. Persistent sensor faults go to Roborock customer service.
Frequently asked questions
Where are the cliff sensors on a Roborock?
On the underside, around the front and sides of the robot, facing the floor.
What should I clean Roborock cliff sensors with?
A soft, dry cloth. They are optical sensors, so the aim is simply to remove the dust film.
Sources checked
Error meanings can vary by model. This guide was checked against the documentation above; use the manual for the model number on your own appliance when it differs.
Related Roborock codes
- Roborock Robot Vacuum Error 1 Roborock Error 1 means the LiDAR turret on top of the robot, or its laser, is blocked.
- Roborock Robot Vacuum Error 2 Roborock Error 2 means the front bumper is stuck in its pressed position.
- Roborock Robot Vacuum Error 3 Roborock Error 3 means the wheels are suspended: the robot has been lifted or is hung up on something so its wheels are off the floor.
- Roborock Robot Vacuum Error 5 Roborock Error 5 means the main brush is jammed and needs to be taken out and cleaned.
More: all Roborock robot vacuum codes · all Roborock codes · search by symptom