Levoit humidifier shows E2 and stops producing mist or will not start.

Safety: Unplug the humidifier and remove the water tank before any disassembly.

Diagnostic and fix steps:

• Reset: Disconnect power for 5–10 minutes, then reconnect. If E2 clears temporarily and returns, the sensor is likely failing.
• Locate humidity sensor: On Levoit smart humidifiers, the humidity sensor is usually a small plastic module with vent holes, mounted near the air outlet or on the internal air path, connected by a 3–4 wire harness to the main PCB.
• Check for moisture and deposits: If the sensor is visibly wet or has white mineral deposits, gently dry it with a soft cloth and allow the unit to air dry for several hours. Do not use chemicals or soak the sensor.
• Inspect connector: Ensure the sensor plug is firmly seated on the control board. Unplug and re‑plug to improve contact.
• Replace sensor: If E2 persists, replace the humidity sensor module with a compatible Levoit part. Transfer any mounting brackets or clips from the old sensor to the new one.
• Control board: If a new sensor does not resolve E2, the humidity sensing circuit on the main PCB is likely defective and the board should be replaced or serviced by a technician.