Robot vacuum will not start cleaning and reports E1 shortly after power-on.

Safety first: Power the robot OFF and remove it from the charging dock. If possible, flip the main power switch on the underside to OFF.

• Inspect the left wheel: Turn the robot upside down on a soft surface. Manually rotate the left wheel. It should spin freely with light resistance. Remove hair, threads, or debris wrapped around the wheel axle and inside the wheel well.
• Clean wheel cavity: Use tweezers and a soft brush to clear dust and debris from the left wheel opening and suspension area. Check for small toys or stones wedged above the wheel.
• Check wheel travel: Gently press the left wheel up and down. It should move smoothly in and out of the chassis. If it is stuck, clean around the suspension spring and pivot points.
• Reset the robot: Turn the main power switch back ON, place the robot on a flat floor, and press the power/clean button or start from the Ultenic app. Observe whether the wheel now turns.
• If the error persists: The left wheel motor or encoder assembly is likely faulty. Replacement of the left wheel module is recommended. This usually requires removing the bottom cover (small Phillips screws) and disconnecting the wheel module cable from the main board. If you are not comfortable opening the unit, contact an Ultenic service center.