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Error code reference

LG Range Error Code F5

Warming drawer sensor shorted

LG codesLG range codes

Warming drawer sensor shorted — warm drawer thermistor shorted for over 1 minute after warming drawer operates.

First step from the service manual

Unplug range or disconnect power, check continuity of the sensor and Control (PCB), disconnect sensor from harness and measure resistance (approximately 50kΩ at 77°F/25°C for F5 per failure codes table; approximately 4.6kΩ per component test).

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

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What F5 means on a LG range

The F5 error code on an LG range indicates that the warming drawer thermistor has entered a shorted condition that persisted for more than one minute while the warming drawer was in operation. A thermistor is a temperature-sensitive resistor whose resistance changes predictably with temperature. When the thermistor shorts, it sends a signal to the control board (PCB) that falls outside the acceptable range, causing the board to interpret the reading as a fault. The warming drawer system relies on this sensor to regulate and maintain a safe, consistent low temperature.

The thermistor for the warming drawer should measure approximately 50 kilohms at 77 degrees Fahrenheit (25 degrees Celsius) according to the failure codes specification, while component-level testing references approximately 4.6 kilohms as a valid reading depending on test conditions. A shorted thermistor will typically read near zero ohms or significantly below the expected resistance value. This discrepancy is what triggers the F5 fault.

Common causes include a damaged thermistor with an internal short, wiring harness issues such as pinched or melted wires causing conductors to contact each other, a failed connector creating an unintended low-resistance path, or a defective control board that is misreading the sensor signal. Diagnosing the fault requires disconnecting power, isolating the sensor from the harness, and measuring resistance directly at the thermistor leads to determine whether the fault lies in the sensor itself or elsewhere in the circuit.

Source: manufacturer service documentation.

Common causes of F5

  1. 01

    Shorted warming drawer thermistor

    Part replacement

    The thermistor itself has developed an internal short, causing resistance to drop well below the expected value (approximately 50 kilohms at room temperature). Disconnect the sensor from the wiring harness and measure resistance directly at the sensor leads to confirm.

  2. 02

    Pinched or damaged wiring harness

    Part replacement

    Wires in the harness running to the warming drawer thermistor can become pinched, melted, or abraded, causing two conductors to contact each other and create a short. Inspect the harness visually for damaged insulation or contact points, especially near sharp edges or heat sources.

  3. 03

    Corroded or failed wiring connector

    Wiring / connection

    The connector between the thermistor and the harness can corrode or sustain damage, creating an unintended low-resistance path that mimics a shorted sensor. Check the connector pins for discoloration, corrosion, or melting.

  4. 04

    Faulty control board (PCB)

    Part replacement

    If the thermistor and harness both test within specification, the PCB may be misinterpreting the sensor signal due to a failed input circuit. This is diagnosed by elimination after confirming the sensor and wiring are good.

See the test procedure for each cause

Frequently asked questions about F5

What does F5 mean on a LG range?
The F5 code on an LG range means the warming drawer thermistor has shorted for more than one minute while the warming drawer was operating. The thermistor is the temperature sensor that the control board uses to regulate warming drawer heat. When the sensor signal falls into a shorted range, the control board flags the fault to prevent unsafe operation. The root cause can be the sensor itself, the wiring harness, or the control board.
Can I fix the F5 error myself?
A knowledgeable DIYer can tackle the initial diagnostics by unplugging the range, locating the warming drawer thermistor, disconnecting it from the harness, and measuring its resistance with a multimeter. A reading near zero ohms or far below approximately 50 kilohms at room temperature confirms a shorted sensor that needs replacement. Harness repairs and control board replacement are also possible for those comfortable with appliance wiring, but working inside the range does require safe power disconnection practices.
Is it safe to use my LG range with an F5 error?
You should avoid using the warming drawer while the F5 error is active, as the control board cannot accurately monitor temperature without a functioning thermistor. The rest of the range may still operate normally, but continued use of the warming drawer under this fault condition could result in unregulated heating. It is best to resolve the fault before relying on the warming drawer again.
How much does it cost to repair an F5 error on an LG range?
If only the thermistor needs replacement, parts typically cost in the range of $15 to $50 depending on the specific model. Professional labor to diagnose and replace the sensor generally adds $75 to $150 or more. If the control board is the cause, board replacement parts can range from $100 to $300 or higher, and total repair costs including labor may reach $200 to $450.
Will resetting my LG range clear the F5 error?
Unplugging the range or disconnecting power may temporarily clear the F5 code, but the error will return as soon as the warming drawer operates again if the underlying fault has not been corrected. A reset does not fix a shorted thermistor or damaged wiring. Permanent resolution requires identifying and replacing or repairing the faulty component.

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