Dehumidifier shows E3 and stops dehumidifying; compressor does not start.

Safety: Disconnect power before opening the control panel. Avoid static discharge when handling electronic boards and sensors.

• Locate the humidity sensor: On many Midea dehumidifiers, the humidity sensor is mounted behind the front grille near the air intake or integrated into the control panel area, connected by a small harness to the PCB.
• Inspect sensor and wiring: Remove the front bezel or control panel cover. Look for a small plastic module or PCB labeled as humidity sensor. Check for dust buildup, corrosion, or broken wires.
• Clean the sensor area: Use a soft brush or compressed air to gently remove dust from the sensor vents. Do not use liquid cleaners directly on the sensor.
• Reseat connectors: Unplug and replug the humidity sensor connector on both ends (sensor and main PCB) to ensure good contact.
• Functional check: Reassemble enough to power the unit safely. Plug in and see if E3 clears. If it returns immediately, the sensor is likely defective.
• Replace humidity sensor: Order a "Midea humidity sensor" or "RH sensor" for your model. Swap the module, matching orientation and connector. Route wires as originally installed.
• If new sensor does not fix E3: The main PCB's humidity input circuit may be faulty. Replace the main control board.