The vacuum makes a high-pitched whistling noise during use.

Safety first: Turn OFF the vacuum and remove the battery before inspecting for cracks.

Step-by-step checks:

• 1. Localize the sound: Run the vacuum briefly and listen closely (keeping fingers and hair away from moving parts) to identify where the whistle originates—bin area, wand, or floor head.
• 2. Inspect seals: Remove and reseat the dust bin and filter covers. Check that all latches are fully engaged and that gaskets are not twisted.
• 3. Check for cracks: Examine the wand and main body for hairline cracks, especially near joints. Flex the wand gently; if the sound changes, a crack may be opening under load.
• 4. Temporary test with tape: As a diagnostic step, wrap suspected crack areas with masking or duct tape and test again. If the whistling stops, replace the cracked component.

When to stop: Persistent whistling with no visible damage may indicate an internal seal issue that requires partial disassembly.