Robot lawnmower shows E20 Docking Error; mower cannot align with or stay in the NAC charging station.

Safety first: Turn OFF the mower before manually moving it or adjusting the charging station.

• Check station placement: Ensure the NAC charging base is level, on firm ground, and installed according to the manual (clearance in front and sides).
• Inspect docking rails: Straighten any bent metal or plastic guides that help align the mower into the base.
• Verify guide wire: If your model uses a guide wire, inspect it for breaks and correct routing back to the base.
• Clean front sensors: Wipe any infrared or contact sensors on the front of the mower that help detect the base.
• Test manual docking: Gently push the mower into the base until it is fully seated. If E20 still appears, the docking sensor or base electronics may be faulty.

Warning: Do not modify the base mechanically beyond straightening guides; incorrect geometry can cause further docking issues.