AIRCARE digital humidifier or dehumidifier displays E1 and will not operate or shuts down shortly after starting.

Safety first: Unplug the unit before removing any covers. Dehumidifiers and some humidifiers contain high-voltage components.

• Step 1 – Power reset: Unplug the unit for 5–10 minutes to discharge the control board, then plug back in. If E1 clears temporarily and returns, continue with inspection.
• Step 2 – Access the control compartment: Remove the rear or side panel (on dehumidifiers) or top cover (on console humidifiers) by taking out the screws. Keep track of screw locations.
• Step 3 – Locate the thermistor: The temperature sensor is usually a small bead-type sensor on two wires, clipped near the air intake or evaporator coil (dehumidifier) or near the air inlet (humidifier). Follow the thin wire harness back to the main PCB.
• Step 4 – Check connections: Ensure the thermistor plug is fully seated on the control board. Look for corrosion, broken wires, or pinched harnesses. Reseat the connector.
• Step 5 – Inspect sensor physically: If the sensor bead is cracked, corroded, or broken off, it must be replaced. Order a replacement thermistor specified for your AIRCARE model.
• Step 6 – Replace thermistor (if needed): Disconnect the old sensor, route the new sensor along the same path, secure it with clips or ties away from moving parts, and plug it into the same board connector.
• Step 7 – Reassemble and test: Reinstall panels, plug in the unit, and power ON. Confirm that E1 is cleared and the unit runs normally.

If E1 persists with a known-good thermistor and wiring, the main control board is likely defective and may need replacement by a qualified technician.