High-pitched whistling noise and reduced suction.

Safety first: Unplug before handling internal parts.

• Check tank seals: Ensure the dirty tank lid is fully latched and gasket is intact.
• Inspect hose: Flex the hose and listen for changes in the whistle. Replace if cracks are found.
• Check nozzle seal: Inspect the rubber skirt or seal at the nozzle. Replace if torn or deformed.
• Use hand over joints: While running (for brief tests), move your hand around joints to feel for escaping air, then unplug and correct leaks.