Vacuum runs but suction is very weak, and an E3 indicator or red LED appears when switching to high power mode.

Safety first: Turn off the vacuum and remove the battery before disassembling any parts. Do not operate the vacuum without filters unless the manual explicitly allows it for testing.

• Step 1 – Empty the dust container: Remove the dust bin from the Princess cordless vacuum and empty it fully. Tap the bin gently to dislodge compacted dust.
• Step 2 – Clean the cyclone assembly: Detach the cyclone unit from the bin. Use a soft brush to remove fine dust from the cyclone cones and mesh. Do not immerse the cyclone in water unless the manual states it is washable.
• Step 3 – Wash the pre‑motor filter: Remove the foam or fabric pre‑motor filter. Rinse under lukewarm running water until clear. Do not use detergents. Squeeze gently and allow to air‑dry for at least 24 hours.
• Step 4 – Check/replace the HEPA exhaust filter: Access the rear or top HEPA filter (often behind a grill). If heavily grey or deformed, replace it with a genuine Princess HEPA filter cartridge. If washable, rinse gently and dry completely.
• Step 5 – Inspect wand and hose: Look through the wand and any flexible hose for blockages. Push out debris with a broom handle or flexible rod, taking care not to puncture the tube.
• Step 6 – Reassemble and test: Refit all filters and the bin. Install the battery and test suction on low and high modes. If E3 still appears with clean filters and clear airflow, the airflow sensor or control PCB may be faulty and require professional replacement.