AL04
Fagor Ambient Temperature Sensor Fault

Freezer displays AL04; compressor may not start or may run erratically; temperature may drift.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Defective ambient NTC sensor, Sensor wiring damaged near control panel, Loose connector at display/control PCB, Faulty display/control PCB

How to Fix / Troubleshooting

Safety first: Disconnect mains power before removing the top cover or control panel.

  • Locate ambient sensor: On many Fagor upright freezers, the ambient sensor is near the control/display panel or behind the front grille, sensing room temperature.
  • Visual inspection: Check that the sensor capsule is intact and not broken or corroded. Inspect the cable for pinching where it passes through cabinet holes.
  • Check connections: Remove the control panel cover and verify the sensor connector is fully seated on the PCB. Clean any oxidation with contact cleaner and reconnect.
  • Test sensor: With the freezer unplugged, measure resistance at room temperature. Compare to expected NTC values (often 5–20 kΩ). Replace the Fagor ambient NTC sensor if readings are open, shorted, or unstable.
  • Control PCB: If a new sensor does not clear AL04, the display/control PCB may be defective and should be replaced as an assembly following Fagor service procedures.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Ambient NTC Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements