Machine emits a high-pitched whistling noise during use

Safety first: Unplug the machine before checking connections.

• Check all joints: Inspect hose-to-body, wand-to-hose, and wand-to-head connections. Ensure they click or twist-lock fully.
• Inspect seals: Look at rubber cuffs and O-rings for cracks or deformation. Replace worn SEBO seals or cuffs.
• Check nozzle: Examine the floor nozzle opening for small objects (coins, toys) that can cause whistling. Remove any obstructions.
• Bag door and filter covers: Ensure these close fully and latch. Replace damaged latches or seals.

Persistent whistling often indicates a minor air leak that can reduce suction efficiency over time.