Vacuum runs for a few seconds then stops; battery indicator shows full; error LED blinks three times in a repeating pattern.

Safety first: Power OFF and remove the battery pack. Allow the unit to cool for at least 20 minutes before further inspection.

• Empty the dust bin: Remove the dust container from the main body. Empty all debris and wipe the inside with a dry cloth. Ensure the cyclone shroud holes are not packed with fine dust.
• Clean the pre-motor filter: Locate the foam or fabric pre-motor filter (usually inside or behind the dust bin). Tap it gently over a trash can to remove dust. If washable per Tristar instructions, rinse with lukewarm water only, squeeze out excess water, and let it air-dry completely (24 hours) before reinstalling.
• Check the HEPA exhaust filter: Remove the rear or top HEPA filter. Tap gently to remove dust. Replace if heavily discolored, torn, or if airflow remains weak after cleaning.
• Inspect airflow path: Check the wand, hose (if equipped), and nozzle for blockages. Remove any obstructions.
• Test again: Reassemble all components, reinstall a fully charged battery, and run the vacuum. If it still overheats and stops quickly with clean filters and clear airflow, the main motor may be failing and should be replaced by a technician.