F4
OKP
Motor Speed Feedback / Hall Sensor Fault
F4 displayed, vacuum runs but speed fluctuates or pulses up and down.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Failed Hall effect sensor in motor, Loose motor feedback wiring, Faulty speed control circuit on PCB, Debris interfering with motor rotation
How to Fix / Troubleshooting
Safety first: Remove the battery before inspection.
- Clear airflow and filters: Ensure there is no heavy blockage causing the motor to surge (see E2 cleaning steps).
- Listen to motor: With the battery reinstalled, briefly run the vacuum. If you hear scraping or grinding, stop immediately; the motor bearings or fan may be damaged.
- Check for vibration: Excessive vibration can disturb speed feedback. If the unit vibrates strongly, see the vibration/noise symptom entries for brush and motor checks.
- If F4 continues: The main suction motor assembly (with integrated speed sensor) or main control PCB must be replaced. This is not a user‑serviceable repair.
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Repair Difficulty
Professional Required
5/5
Required Part
Main Suction Motor Assembly
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