Cordless vacuum stops and displays E3 or flashes three times; suction drops suddenly during use

Safety first: Switch OFF the vacuum, remove the battery pack, and allow the unit to cool for at least 20 minutes before further inspection.

Step-by-step checks:

• 1. Empty the dust bin: Detach the dust container and empty it completely. Wipe the inside with a dry cloth to remove fine dust buildup around the cyclone shroud.
• 2. Clean the pre-motor filter: Remove the pre-motor filter (usually a foam or fabric filter near the dust bin). Tap it gently over a trash can to remove dust. If the manual allows, rinse with lukewarm water only, then air-dry for at least 24 hours until completely dry before reinstalling.
• 3. Check the cyclone and inlet: Inspect the cyclone cone and the inlet port for compacted dust or foreign objects. Use a soft brush to dislodge debris; do not use sharp tools that could puncture plastic.
• 4. Inspect the exhaust/HEPA filter: Locate the rear or top exhaust filter. Remove and tap out dust. If washable per the manual, rinse and fully dry. A blocked exhaust filter can cause heat buildup and trigger E3.
• 5. Verify airflow: With filters cleaned and the bin reinstalled, run the vacuum briefly (battery reinserted) and feel for strong airflow at the exhaust. Weak exhaust flow after cleaning suggests internal blockage or a failing motor cooling fan.

When to stop: If E3 recurs quickly after thorough cleaning and cooling, the motor’s thermal sensor or cooling fan may be failing. Continued use could damage the motor; seek professional service or replace the main motor assembly.