Vacuum display shows E09 or a filter icon with an exclamation mark; suction is reduced.

Safety first: Remove the battery pack before removing filters.

• 1. Remove and inspect filters: Take out the pre-motor foam/filter cartridge and the HEPA exhaust filter. If they are visibly dirty or grey, they need cleaning or replacement.
• 2. Clean or replace: If your Grundig model uses washable filters, rinse them under lukewarm water until clear. Do not use detergents. Allow at least 24 hours to dry completely. If non-washable, replace with genuine Grundig filters.
• 3. Clean sensor ports: Some models have small holes near the dust bin or filter housing for airflow sensing. Gently blow air or use a soft brush to remove dust from these ports.
• 4. Reset indicator: After reinstalling dry filters, press and hold the filter reset button (if available) according to the user manual to clear the E09 warning.
• 5. If E09 persists with new filters: The airflow/pressure sensor or its wiring on the main PCB may be faulty and should be checked by a technician.