Cordless vacuum displays E4 or flashes four times and suction is very weak even with a clean bin

Safety first: Remove the battery pack before cleaning internal parts. Do not operate the vacuum without filters unless specifically instructed for testing.

• Empty dust bin: Remove and empty the dust container. Tap it gently to dislodge fine dust from the cyclone.
• Clean pre-motor filter: Remove the foam or fabric filter located before the motor. If washable, rinse under lukewarm water until clear. Squeeze out excess water and allow to dry completely (24 hours) before reinstalling.
• Check wand and hose: Detach the wand and any flexible hose. Look through them against a light source. Use a broom handle or flexible rod to push out any blockage, taking care not to puncture the tube.
• Inspect exhaust/HEPA filter: Remove the rear or top HEPA filter. If heavily clogged or damaged, replace it. Some Medion models have non-washable HEPA filters—follow the user manual.
• Cool-down period: If the vacuum shut down due to overheating, allow it to cool for at least 30 minutes before testing again.