Vacuum displays E13 and motor speed surges up and down without user input

Safety first: Remove the battery and wait for the motor to stop completely before opening the housing.

• 1. Clean motor area: Open the housing and gently blow out dust from around the motor and any small sensor boards attached to it. Avoid spinning the fan excessively with compressed air.
• 2. Inspect tachometer wiring: Locate the small wires leading from the motor to the control board (separate from the main power leads). Ensure the connector is secure and wires are not damaged.
• 3. Check sensor mounting: Verify that the speed sensor board or pickup is firmly mounted and correctly aligned with the motor rotor or magnet ring.
• 4. Test operation: Reassemble and test the vacuum. If E13 persists and the motor still surges, the tachometer sensor or control board is likely defective.
• 5. Replace sensor or control module: Replace the motor speed sensor assembly if it is a separate part. If integrated into the motor or control PCB, the entire motor assembly or control electronics module must be replaced by Festool service.