When a Dyson SV12 (V10) vacuum:

• Revs up five to seven times, then stops, and
• The filter light flashes,

this usually means there is a problem with airflow or the filter sensor — even if the filter looks clean.

• Remove the purple filter (on the back end).
• Inspect the rubber gasket/seal for dust, hair, or damage.
• Wash thoroughly under cold water — both the inner cone and outer foam.
• Shake out water and allow to dry completely for 24–48 hours.
• Reinstall securely (turn clockwise until it clicks).

Tip: A slightly damp filter will trigger the same fault again.

Even after general cleaning, inspect these often-missed spots:

• Wand and cleaner head: Look through for obstructions or compacted dust.
• Cyclone assembly: Tap gently or use compressed air to remove fine dust.
• Bin inlet flap: Ensure it opens and closes freely.

• Remove the wand and head — run the vacuum with only the main body and filter.
• If it runs normally: blockage or restriction is in the wand or head.
• If it still revs and stops: issue is in the main unit (filter, seal, or motor).

• While running, feel for air escaping around the filter joint.
• If you feel a leak, the filter may not be sealing tightly.
• Temporary test: wrap a thin band of tape or rubber around the seal.
• If this fixes it, replace the filter or filter housing.

• Filters can fail internally or trigger false sensor readings.
• Borrow one from another Dyson V10/SV12 if possible, or replace yours.
• Genuine Dyson filters work best — avoid cheap knockoffs.

If none of the above resolves the issue:

• The motor or mainboard airflow sensor may be faulty.
• Contact Dyson Support — they often replace the main body for a fixed fee (≈$100–$150), cheaper than buying new.