Robot lawnmower shows E18 and stops; may indicate sensor error in the manual.

Safety first: Turn OFF the mower and disconnect the charging station before servicing sensors.

• Locate rain sensor: Find the rain sensor on the top housing (often a small grid or pad). Clean it gently with a soft cloth to remove dirt and algae.
• Check for trapped water: Ensure there is no standing water trapped around or under the sensor. Dry the area thoroughly.
• Inspect wiring: Open the housing and trace the rain sensor cable to the mainboard. Check for pinched, cut, or corroded wires and connectors.
• Test function: If the mower has a menu option to disable the rain sensor, temporarily disable it and see if E18 disappears. Do not operate long‑term with a known faulty sensor in wet conditions.
• Replace sensor: If cleaning and wiring checks do not resolve the error, replace the rain sensor module with an Einhell‑compatible part.