Essick Air digital humidifier shows E2 and does not maintain humidity setpoint; may not run at all.

Safety first: Unplug the unit before opening the control housing.

• Reset the unit: Unplug for 5–10 minutes, then plug back in and test. Temporary glitches can trigger E2.
• Locate the humidity sensor: On many Essick Air digital consoles, the humidity sensor is mounted behind the front grille or integrated into the control board. Remove the control panel cover to access it.
• Inspect and clean: If the sensor is a small module or probe, gently clean around it with a dry, soft brush to remove dust. Do not use liquids directly on the sensor.
• Check connections: Ensure the sensor connector is firmly seated on the control PCB and that no pins are bent or corroded.
• Test operation: Reassemble, plug in, and set a humidity level. If E2 persists or the unit cannot sense humidity correctly, the sensor or control board must be replaced.

Because the humidity sensor is often integrated with the control board on Essick Air units, replacement may involve swapping the entire control assembly.