Freezer displays E1 and temperature is not cold enough or fluctuates

Safety first: Unplug the freezer from the mains before removing any panels or touching wiring. Use insulated tools only.

Step-by-step checks:

• 1. Power reset: Disconnect power for 5–10 minutes, then reconnect. If E1 clears and does not return, it may have been a transient fault.
• 2. Locate the cabinet NTC: On most AEG freezers, the temperature sensor is clipped behind the inner liner, often near the evaporator cover or in a small plastic housing on the rear wall.
• 3. Inspect wiring: Remove the internal panel (usually held by screws or clips). Check the NTC leads for cuts, pinches, or signs of moisture ingress. Reseat any in-line connectors.
• 4. Test the sensor: With the freezer unplugged, disconnect the NTC from the harness and measure resistance with a multimeter. At room temperature (around 20°C), most AEG NTCs read roughly 4–10 kΩ. If it is open circuit (OL) or shorted (near 0 Ω), the sensor is faulty.
• 5. Check at the PCB: Access the main control board (often in a rear lower compartment). Verify continuity from the NTC connector to the PCB plug. Repair or replace damaged harness sections.
• 6. Replace the NTC: If readings are out of spec, install a genuine AEG freezer temperature sensor. Route the new sensor exactly as the original to avoid contact with moving parts or sharp edges.
• 7. Reassemble and test: Refit panels, restore power, and monitor if E1 reappears and if the freezer reaches set temperature.

When to call a technician: If the NTC and wiring test good but E1 persists, the main control board may be defective and should be diagnosed or replaced by a professional.