Cordless SEBO vacuum makes a high-pitched whistling noise during use.

Safety first: Turn off the vacuum and remove the battery before inspecting for cracks or loose parts.

• Localize the sound: Run the vacuum briefly and listen for where the whistle is loudest (bin area, wand, nozzle). Then power off and inspect that area.
• Check bin seal: Remove the dust bin and inspect the rubber gasket around its rim. If it is twisted, dirty, or damaged, clean it and reseat carefully. Replace if torn.
• Inspect wand and hose: Look for hairline cracks or splits, especially near joints. Flex the wand slightly and watch for openings. Replace the wand or hose if cracked.
• Verify filter covers: Ensure the pre-motor and exhaust filter covers are fully latched. A loose cover can create a whistle and reduce suction.