Fan speed lowered / weak suction — filter blocked
Where to look: Robot dustbin washable filter (and dustbin itself).
Official “fan speed lowered” guidance: check a blocked strainer/filter and replace the filter if cleaning does not restore suction. Wet filters must dry thoroughly before reuse.
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Quick answers
What is wrong?
Official “fan speed lowered” guidance: check a blocked strainer/filter and replace the filter if cleaning does not restore suction. Wet filters must dry thoroughly before reuse.
What you might notice
- Fan speed lowered alert
- Weak suction / dust falling out
- Filter looks grey or damp
Can I fix this myself?
Often yes with careful cleaning. Difficulty: medium · about 15 min + up to 24 h drying. If unsure or it returns after parts cleaning, use mail-in repair.
What you need
- Clean water
- Soft cloth
Do this
- Empty the dustbin. Remove the washable filter.
- Rinse the filter repeatedly and tap out dirt. Do not scrub the filter media with brushes or fingers.
- Allow at least 24 hours for the filter to dry thoroughly (use a spare filter if you have one).
- Wash the dustbin, dry it, reinstall filter and bin firmly.
- If the fan-speed / weak-suction error continues with a dry clean filter, replace the filter. If it still fails, request fan (Error 18 path) repair — do not open the fan housing.
Parts (only if cleaning fails)
- Washable filter
- Vacuum fan module (service if Error 18 persists)
Official references
- https://support.roborock.com/hc/en-us/articles/360035731751-What-should-I-do-when-fan-speed-lowered-error-occurs
- https://support.roborock.com/hc/en-us/article_attachments/900001170566
- https://support.roborock.com/hc/en-us/article_attachments/34928674877081