Error 42: Dock maintenance brush jammed
Where to look: Dock cleaning sink — high-speed maintenance brush module and water filter.
Error 42 — dock maintenance brush jammed. Left-side stop = physical jam; right-side stop = water filter blocked or not seated (S8 Pro Ultra / Saros manuals).
Picture
Quick answers
What is wrong?
Error 42 — dock maintenance brush jammed. Left-side stop = physical jam; right-side stop = water filter blocked or not seated (S8 Pro Ultra / Saros manuals).
What you might notice
- Error 42 voice/app alert
- Mop wash interrupted
- Brush module stuck left or right
Can I fix this myself?
Often yes with careful cleaning. Difficulty: medium · about 15-30 min. If unsure or it returns after parts cleaning, use mail-in repair.
What you need
- Soft cloth
- Tweezers
Do this
- If the brush module stopped on the left, remove debris jamming it.
- If it stopped on the right, clean or reseat the water filter in the cleaning sink until it clicks.
- Wipe the cleaning tank dry of grit. Retry mop washing.
- If Error 42 returns with a clear brush path and locked filter, request dock brush-module repair.
Parts (only if cleaning fails)
- Cleaning sink water filter
- Maintenance brush module (service)
Official references
- https://support.roborock.com/hc/en-us/article_attachments/18342044174873