Display shows E1; freezer may continue to run but temperature control is unreliable.

Safety first: Unplug the appliance before removing any covers or touching wiring.

• Power cycle: Disconnect power for 5 minutes and reconnect. If E1 returns, proceed with sensor checks.
• Access sensor: Locate the internal temperature sensor cover inside the Fagor freezer (often a small plastic cap on the rear wall). Remove it carefully.
• Inspect and reseat: Check the sensor body and wiring for moisture or damage. Follow the cable to the top or rear where it connects to the control board and reseat the connector.
• Measure resistance: With a multimeter, measure sensor resistance at room temperature. Replace the Fagor internal NTC sensor if readings are out of specification or intermittent when the cable is flexed.
• Control board check: If a new sensor does not clear E1, the control PCB may be defective and should be replaced.