Cordless vacuum makes a high‑pitched whistling noise during use.

Safety first: Turn OFF and remove the battery before close inspection.

• Localize the sound: Run the vacuum briefly (with battery) and listen carefully to identify where the whistle is loudest (bin, wand joint, filter cover).
• Inspect for cracks: Remove the dust bin and examine it under good light for hairline cracks, especially around joints and latches.
• Check seals and covers: Ensure the filter cover is fully latched and the rubber seals are seated correctly without twists.
• Test joints: While running, gently press on joints (wand to body, bin to body). If the noise changes, that joint is leaking.
• Replace damaged parts: Replace any cracked plastic components or worn seals. Do not attempt to glue pressure‑bearing parts, as this may fail and leak again.