Robot mower shows E20 and stops; may be associated with rain or wet grass.

Safety first: Avoid working on the mower in thunderstorms or heavy rain. Turn OFF power before opening covers.

Steps to check:

• Dry conditions: Move the mower and charging base to a dry area. Allow them to dry for several hours.
• Inspect rain sensor: Locate the rain sensor on the top housing (often a small recessed area). Clean off dirt, pollen, and debris with a soft cloth.
• Check wiring: Open the housing and ensure the rain sensor connector is firmly attached to the main PCB.
• Adjust settings: In the app or menu, verify rain delay settings and ensure they are not preventing operation longer than expected.

When to call a technician: If E20 appears in dry conditions with a clean sensor, the rain sensor module may need replacement.