Dehumidifier stops and displays E2; fan may still run briefly.

Safety warning: Disconnect the appliance from mains power before opening any panels. Sharp metal edges around the coil can cause injury; wear cut-resistant gloves.

Steps:

• Unplug and allow to thaw: If there is visible ice on the coil, let the unit sit unplugged for at least 30–60 minutes so the evaporator can defrost.
• Remove front or side cover: On most Challenge dehumidifiers, remove the water bucket, then undo screws at the back and sides to lift off the front housing and access the evaporator coil.
• Locate the evaporator sensor: Look for a small NTC probe clipped directly to the evaporator fins or copper tubing, usually wrapped or taped in place, with two wires leading to the PCB.
• Check the sensor and wiring: Ensure the sensor is firmly clipped to the coil and not hanging loose. Look for damaged insulation, corrosion, or broken wires. Reseat the connector on the PCB.
• Test with a multimeter: Disconnect the sensor and measure resistance. It should show a stable kΩ reading (not 0 or infinite). If it reads open or short, replace it.
• Replace if needed: Purchase a compatible Challenge evaporator temperature sensor (NTC). Remove the old sensor clip or tape, install the new sensor in the same position on the coil, and reconnect to the PCB.
• Reassemble and test: Refit the covers and bucket, plug in, and run the unit. The E2 code should clear if the sensor circuit is restored.

Note: If the sensor tests good but E2 persists, the main PCB may have a defective sensor input circuit and may require replacement.