Robot mower shows E5 and refuses to start mowing; often after rain or washing.

Safety first: Switch OFF the mower and disconnect from charging station.

• Dry the mower: Move it to a dry, sheltered area. Wipe the top panel and rain sensor area with a dry cloth. Allow the mower to dry for several hours at room temperature.
• Check storage location: Ensure the charging station is under a canopy or in a place where rain does not constantly fall on the mower.
• Disable rain mode (if supported): Some Hecht models allow disabling the rain sensor in the settings menu. Only do this if you are sure the mower will not be used in heavy rain.
• Inspect for visible cracks: Look for cracks around the rain sensor window or top cover seals that could allow water in. Replace damaged Top Cover / Rain Sensor Window if needed.
• If E5 persists when dry: The Rain Sensor Board or main PCB input may be faulty. A technician should test the sensor resistance and replace the rain sensor module if it is shorted or open.