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Error code reference

LG Refrigerator Error Code F5

Failure of middle compartment defrosting sensor

LG codesLG refrigerator codes

Failure of middle compartment defrosting sensor - sensor is disconnected or shorted.

First step from the service manual

Check wiring of the middle compartment defrosting sensor.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
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What F5 means on a LG refrigerator

The F5 error code on an LG refrigerator indicates a fault with the middle compartment defrosting sensor. This sensor is a thermistor, a temperature-sensitive resistor that monitors the defrost cycle in the middle section of the refrigerator. The control board uses readings from this sensor to determine when defrosting has reached the appropriate temperature and when to terminate the defrost cycle. When the board detects that the sensor signal is outside the expected range, either because the circuit reads an open (disconnected) or a short (shorted), it triggers the F5 code.

The two primary electrical failure states are an open circuit and a short circuit. A disconnected sensor or a break in the wiring harness causes an open circuit, which the control board reads as an implausibly high resistance value. A short circuit occurs when wires contact each other or when the thermistor itself fails internally, causing resistance to drop near zero. Both conditions produce an invalid temperature reading, making the control board unable to manage the defrost cycle correctly.

Left unaddressed, an F5 fault can cause frost accumulation in the middle compartment, reduced cooling efficiency, and potential food spoilage. The first step in diagnosis is inspecting the wiring harness connected to the middle compartment defrosting sensor, checking for visible damage, corrosion, loose connectors, or pinched wires. If the wiring is intact, the sensor itself should be tested with a multimeter to confirm whether its resistance is within the expected range for the compartment temperature.

Source: manufacturer service documentation.

Common causes of F5

  1. 01

    Loose or disconnected sensor connector

    Wiring / connection

    The wire harness connector attached to the middle compartment defrost sensor may have come loose, especially after moving the refrigerator or during a previous repair. Inspect the connector at both the sensor end and the harness end for a secure fit.

  2. 02

    Damaged wiring harness

    Part replacement

    The wiring between the control board and the sensor can become pinched, frayed, or broken over time, particularly at points where the harness bends or routes through panels. A visual inspection and continuity test with a multimeter will identify any breaks in the circuit.

  3. 03

    Failed defrost sensor (thermistor)

    Part replacement

    The thermistor itself can fail internally, resulting in either an open or shorted condition. Testing the sensor with a multimeter and comparing the resistance reading to the expected value for its current temperature will confirm whether the sensor has failed.

  4. 04

    Corrosion at connector terminals

    Wiring / connection

    Moisture inside the refrigerator compartment can cause corrosion to build up on the sensor connector terminals, increasing resistance and disrupting the signal. Look for discoloration or oxidation on the metal pins and clean or replace the connector as needed.

  5. 05

    Faulty control board

    Part replacement

    If the sensor and all wiring test within normal parameters, the control board itself may be misreading the sensor signal due to an internal fault. This is the least likely cause and should only be considered after all other components have been ruled out.

See the test procedure for each cause

Frequently asked questions about F5

What does F5 mean on a LG refrigerator?
The F5 code on an LG refrigerator signals a failure of the middle compartment defrosting sensor. The control board has detected that the sensor circuit is either open (disconnected) or shorted, meaning the sensor is not providing a valid temperature reading. This prevents the refrigerator from properly managing the defrost cycle in the middle section of the unit.
Can I fix the F5 error code myself?
In many cases, yes. Start by checking the wiring harness connected to the middle compartment defrost sensor for loose connectors, visible damage, or corrosion. If the wiring looks intact, use a multimeter to test the sensor's resistance and check for continuity through the harness. Replacing a sensor or repairing a connector is a manageable repair for someone comfortable working with appliance wiring.
Is it safe to keep using my refrigerator while the F5 code is showing?
Continued use with an active F5 error is not recommended for extended periods. Without a functioning defrost sensor, the refrigerator cannot properly control its defrost cycle, which can lead to frost buildup, reduced cooling performance, and potential food spoilage. Address the fault as soon as possible to avoid further issues.
How much does it cost to repair the F5 error on an LG refrigerator?
If the fix is a loose connector or minor wiring repair, the cost can be minimal, covering only your time and possibly a small wiring repair kit. Replacing the defrost sensor itself typically costs between $15 and $60 for the part. If a professional technician is needed, expect total repair costs ranging from $100 to $250 depending on labor rates in your area.
Will resetting my LG refrigerator clear the F5 error code?
A reset may temporarily clear the F5 code from the display, but the error will return if the underlying fault with the middle compartment defrost sensor has not been corrected. Resetting without repairing the sensor or wiring does not fix the problem and can allow frost accumulation and cooling issues to continue. The code will only stay cleared once the sensor circuit is functioning correctly.

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