Dehumidifier displays E1 and will not operate normally

Safety first: Unplug the unit before removing any covers.

Steps to resolve E1:

• Power reset: Unplug the dehumidifier for 5–10 minutes, then plug it back in and power on. Temporary glitches can sometimes trigger E1.
• Locate the ambient sensor: Remove the front grille or top cover as per your Whynter manual. The ambient thermistor is usually near the air intake or on the control panel housing.
• Check connections: Find the small two-wire connector from the thermistor to the main control board. Reseat the connector firmly. Look for corrosion or bent pins.
• Inspect the sensor: Ensure the thermistor bead or probe is intact and not broken off. Check the wire insulation for cuts or pinch points.
• Reassemble and test: Put the covers back on, plug in, and test. If E1 persists, the thermistor is likely defective and should be replaced with a compatible Whynter sensor.

Note: Replacing the thermistor usually requires basic tools and careful handling of small connectors. If you are not comfortable opening the cabinet, contact a technician.