Dehumidifier stops and displays E1 on the control panel; fan may still run but no dehumidification

Safety first: Unplug the dehumidifier from the mains before removing any panels. Do not work on the unit while it is connected to power.

Steps to check and address E1 (room sensor):

• 1. Power reset: Unplug the unit for 5–10 minutes, then plug back in and power on. If E1 clears and does not return, it may have been a transient fault.
• 2. Access the control area: Remove the front or top cover (on many Ariston dehumidifiers the control PCB is behind the top fascia). Keep track of screws and avoid pulling on ribbon cables.
• 3. Locate the ambient NTC sensor: This is usually a small thermistor probe on two thin wires leading from the front air intake area to the main PCB, often clipped near the evaporator inlet or behind the front grille.
• 4. Inspect wiring and connector: Check for broken wires, pinched harness, or corrosion at the connector on the main PCB. Reseat the connector firmly. If any wire is cut or insulation is damaged, repair or replace the harness.
• 5. Test the sensor (if you have a multimeter): Disconnect the sensor from the PCB and measure resistance at room temperature. Typical NTC sensors will read between 5–50 kΩ at ~25°C (exact value depends on model). If the reading is open (infinite) or near 0 Ω, the sensor is defective.
• 6. Replace the sensor if faulty: Order a compatible Ariston ambient NTC sensor using the model number. Mount it in the same location and route the wires away from sharp metal edges and moving parts.
• 7. If sensor and wiring are good: The fault may be on the main control board’s sensor circuit. Inspect the PCB for burn marks or corrosion. If present, the main control board will likely need replacement by a qualified technician.

When to call a professional: If you are not comfortable testing resistance or accessing the control board, or if replacing the sensor does not clear E1, contact an authorized Ariston service center.