How to Fix Roborock Main Brush Error
If your Roborock keeps stopping with a main brush error, the problem is usually mechanical rather than electronic.
This guide explains the most common causes, the exact fixes to try, and how to prevent the error from returning.
The main brush system is one of the most heavily used parts of a Roborock robot vacuum, so even small obstructions can trigger a fault.
In many cases, you can resolve it in minutes without replacing parts.
What the Roborock main brush error means
The main brush error is usually a safety alert from the robot vacuum’s brush motor or brush cover detection system.
Roborock models monitor brush rotation and resistance, so if the brush cannot spin freely, the robot may stop and display an error.
This can happen on many Roborock models, including S-series, Q-series, and older devices that use a central roller brush.
The error often points to one of three issues: debris buildup, a misaligned brush assembly, or wear in the brush, bearings, or end caps.
Common causes of a main brush error
Hair, string, and debris wrapped around the brush
Long hair, pet fur, thread, and ribbon are the most common causes.
These materials can tighten around the brush core and create enough drag to trigger the error.
The brush is not seated correctly
If the main brush is not fully inserted or the end caps are not aligned, the vacuum may detect abnormal resistance.
This is especially common after cleaning the brush manually.
The brush cover is not closed properly
Roborock models rely on a secure brush cover.
A cover that is clipped in incorrectly, warped, or blocked by debris can interfere with the sensor or brush movement.
Worn brush bearings or end caps
Over time, the small bearings or end caps at the ends of the roller brush can wear out.
When that happens, the brush may spin unevenly or create friction that causes repeated errors.
Foreign objects trapped in the brush channel
Small items such as twist ties, toy parts, pet litter, cardboard, or hardened dirt can get stuck in the brush chamber and stop the roller from turning smoothly.
Sensor or firmware issues
Less commonly, the error may be caused by a dirty sensor, temporary software glitch, or a firmware bug.
These issues are worth checking after you have ruled out physical obstructions.
How to fix Roborock main brush error step by step
1. Power off the robot and remove the dustbin
Turn off the robot vacuum before touching the brush system.
Remove the dustbin so you can access the brush compartment more easily and avoid accidental movement during inspection.
2. Remove the main brush
Open the brush cover and lift the main brush out of the chamber.
Check whether it comes out smoothly or feels stuck, which may indicate debris in the ends or housing.
3. Clean the brush thoroughly
Use scissors, a seam ripper, or a brush-cleaning tool to remove hair and fibers wrapped around the roller.
Clean the central shaft, both end caps, and the brush ends, since buildup there can create hidden drag.
- Cut hair carefully without damaging the bristles
- Remove sticky dirt from the brush core
- Inspect the rubber fins or bristle sections for damage
- Wipe away dust from the brush housing
4. Check the brush end caps and bearings
Spin the end caps by hand if your model allows it.
They should move freely without grinding or sticking.
If one side feels rough or locked, the end cap or bearing may need replacement.
5. Inspect the brush chamber for obstructions
Look inside the brush cavity with a flashlight.
Remove any debris caught near the motor shaft, side walls, or brush supports.
Even a small object can create enough resistance to trigger the error.
6. Reinstall the brush correctly
Place the main brush back into position with the end caps aligned to the proper slots.
The brush should sit flush and rotate freely when turned by hand.
7. Close the brush cover securely
Make sure the cover clicks into place and lies flat.
If it does not close fully, check for trapped debris, bent tabs, or a damaged latch.
8. Reboot the robot vacuum
Power the device off and on again.
On some models, a restart clears temporary fault states after the brush has been cleaned and reinstalled.
9. Test a short cleaning run
Run the vacuum for a brief test cycle on a hard floor.
Watch for unusual noise, hesitation, or repeated stopping, which can indicate a deeper mechanical problem.
When the error keeps coming back
If the error returns after cleaning, the problem may be related to wear or hardware damage rather than surface debris.
A recurring main brush error often points to a brush that is no longer rolling freely, a damaged cover, or a failing motor drive.
Check these likely failure points:
- Cracked or warped brush cover
- Flattened or damaged brush bearings
- Misshapen roller brush ends
- Loose or noisy motor shaft movement
- Heavy wear on the brush itself
Replacing the main brush with an OEM or compatible Roborock part is often the fastest fix if the current brush is worn.
If the robot still reports an error after a replacement, the issue may be inside the brush motor assembly.
Model-specific checks worth trying
Different Roborock models can show slightly different brush behavior, but the troubleshooting logic is similar.
Some models are more sensitive to dense carpets, pet hair, or third-party brushes that fit poorly.
Use the correct replacement brush
Make sure the roller brush is designed for your exact model.
A brush with the wrong dimensions can create friction or fail to sit properly in the chamber.
Inspect after carpet-heavy cleaning sessions
Thick rugs and high-pile carpet can pack debris tightly around the brush.
If the error appears after carpet cleaning, clean the brush and chamber more frequently.
Update firmware if problems are intermittent
If the hardware looks clean and intact but the error appears randomly, check the Roborock app for firmware updates.
Software updates occasionally improve sensor handling and fault detection.
How to prevent future main brush errors
Routine maintenance is the best way to reduce brush errors and preserve suction performance.
A clean brush spins more easily, puts less strain on the motor, and helps the robot navigate carpets more reliably.
- Clean the main brush weekly if you have pets or long hair
- Inspect the brush ends and cover during every dustbin emptying
- Replace worn brushes and end caps before they fail
- Avoid vacuuming strings, cords, and loose fabric scraps
- Keep the brush chamber free of compacted dust and grit
Regular maintenance also helps other parts of the vacuum, including the side brush, suction path, and drive system, because the robot spends less time fighting resistance in the brush assembly.
When to contact Roborock support
If you have cleaned the brush, confirmed correct installation, tested with a new brush, and the error still appears, the motor or internal sensor may need service.
In that case, contact Roborock support or an authorized repair center with your model number, error details, and a description of the steps you have already tried.
Provide photos of the brush chamber and brush cover if possible.
Clear documentation helps support teams determine whether the issue is a consumable part, a sensor fault, or a hardware repair case.
