Cordless vacuum shows F4 and runs only for a few seconds before shutting off

Safety first: Remove the battery immediately. Do not continue to attempt operation if you smell burning or see smoke.

• Inspect for liquid damage: Check the main body, dirt bin, and motor vents for signs of moisture or residue. If the vacuum was used on wet surfaces (non-wet/dry models), internal shorts may have occurred.
• Check wiring: Remove the nozzle and wand. Inspect visible wiring for cuts, pinch points, or melted insulation. Replace any damaged harnesses.
• Test without accessories: With only the main body and battery, attempt to run the vacuum. If F4 still appears, the fault is likely in the motor or main PCB.
• Do not bypass protection: Never attempt to bridge fuses or bypass safety circuits. Replace the motor assembly or main control board as needed.
• Professional evaluation: Due to fire risk, F4 faults related to short circuits should be evaluated by a qualified technician, especially if liquid damage is suspected.