Vacuum makes a high-pitched whistling noise during use.

Safety first: Remove the battery pack before inspecting joints and seals.

• 1. Localize the sound: Run the vacuum briefly and listen around the bin, wand, and nozzle to identify where the whistle originates. Then power off and remove the battery.
• 2. Check connections: Ensure the dust bin, wand, and nozzle are fully inserted and locked. Re-seat each connection firmly.
• 3. Inspect seals: Look at the rubber seals around the bin and filter cover. If they are deformed or hardened, replace the seal or the associated part.
• 4. Inspect wand/hose: Look for small cracks or pinholes. Replace the wand or hose if damaged.