Dehumidifier runs briefly then stops and shows E2 on the display

Safety: Unplug the Bionaire unit before opening the cabinet. The compressor and fan can start unexpectedly if power is applied.

Diagnostic steps:

• Reset: Disconnect power for 5–10 minutes, then reconnect and check if E2 returns.
• Locate the ambient sensor: On most Bionaire dehumidifiers, the room temperature NTC sensor is clipped near the air intake grille or on the evaporator inlet area, connected by two small wires to the main PCB.
• Inspect wiring: Check the sensor leads for cuts, pinches, or disconnection. Ensure the plug is fully seated on the control board.
• Check sensor resistance: With the unit unplugged, disconnect the sensor and measure resistance with a multimeter. At room temperature (~25°C / 77°F), most NTC sensors read between 5 kΩ and 20 kΩ. A reading of 0 Ω (short) or infinite (open) indicates a bad sensor.
• Replace if faulty: If the sensor is out of spec, replace it with a compatible Bionaire ambient temperature sensor (match connector type and resistance curve).
• Control board check: If a known-good sensor still triggers E2, the main control PCB’s sensor input circuit may be defective and require replacement.