Humidifier/dehumidifier shows E3 and will not regulate humidity correctly.

Safety: Unplug the Argo appliance before opening the control panel or front cover.

Steps:

• Locate the humidity sensor: On many Argo units, the RH sensor is behind the front grille or integrated into the control panel area, exposed to room air via small vents.
• Visual inspection: Check for heavy dust, lint, or signs of condensation damage on the sensor module. If dirty, gently clean with compressed air or a soft brush. Do not use liquid cleaners directly on the sensor.
• Check wiring: Follow the sensor harness to the main PCB. Ensure the connector is fully seated and free of corrosion. Straighten any bent pins.
• Functional test: If you have another compatible Argo unit, temporarily swap the humidity sensor to confirm the fault follows the sensor. Otherwise, if E3 persists after cleaning and reseating, assume sensor failure.
• Replace sensor: Install a new Argo digital humidity sensor module. Mount it in the same orientation and location so it can sense room air correctly.
• Reassemble and test: Refit covers, power on, and set a humidity level. Confirm that E3 is cleared and that the displayed humidity changes when you introduce moist or dry air near the intake.