LG Oven F3 Error Code - Causes & Fix

LG Oven F3 Error Code — What It Means

The F3 error code on LG ovens and ranges does not have a single universal definition across all product lines. In LG’s U.S. support materials for ranges, F3 is identified as a Touch Pad Sensor Key Error, which points to a fault in the keypad or touch panel input. However, LG’s own troubleshooting video for ranges also describes F3 as indicating an open oven sensor. Because LG documents this code differently depending on the appliance family and specific model, you need to verify your exact model number and refer to the model-specific service manual to confirm which system is flagging the fault.

In practical terms, if your LG oven is displaying F3, it is usually either detecting a stuck, shorted, or contaminated touch key on the control panel, or it is seeing an open circuit in the oven temperature sensor. The fault may also stem from faulty wiring between the user interface and the main control board, or from a defective control board itself. LG support notes that some errors can reflect short circuits, communication failures, or overcurrent conditions, so professional inspection is recommended if the code persists after basic troubleshooting.

Jump to Fix

Common Causes

• Stuck, shorted, or contaminated touch keys Moisture, spills, food residue, or an object pressing on the touch panel can cause false key detection and trigger the F3 code.
• Open oven temperature sensor circuit On models where F3 maps to a sensor fault, an open or failed oven thermistor will produce this code.
• Faulty harness or connector wiring Loose pins, corrosion, damaged insulation, or pinched wiring between the user interface and main control board can interrupt signals.
• Defective control board or UI board A failed main control board or user interface assembly may falsely detect key presses or lose sensor communication.

Step-by-Step Fix

1. Power reset the oven by pressing the Power On/Off or Clear/Off button, then turning off the circuit breaker for about 30 seconds to a few minutes and restoring power to see if the code clears.
2. Inspect the touch panel area for moisture, spills, grease, or foreign material, and verify that no key is physically stuck or being pressed by trim or panel distortion.
3. Clean the keypad surface thoroughly with a damp cloth and dry completely, ensuring no residue is shorting the touch sensors.
4. Check the harness and connectors between the keypad and control board for loose pins, corrosion, damaged insulation, or pinched wires, and repair or replace the harness as needed.
5. Test the oven sensor circuit (if your model uses F3 for sensor faults) by isolating the thermistor and checking for an open condition, and replace the sensor if it is open.
6. Verify the touch panel assembly is not falsely closing a key circuit by disconnecting it and observing whether the code clears, then replace the touch pad or user interface assembly if inputs are abnormal.
7. Replace the main control board if the keypad, sensor, and wiring all test good, as the control board is the remaining likely fault point for persistent F3 errors.

Parts Often Needed

When to Call a Pro

Call a qualified appliance technician if the F3 code returns after a power reset, if you are uncomfortable working with live electrical connections, or if you cannot isolate the fault to the keypad or sensor. Because LG uses different fault definitions across product families, a technician with access to the model-specific service manual and diagnostic tools can quickly verify whether the code points to a touch panel fault, an open oven sensor, or a control board failure. Professional diagnosis is also recommended if you see corrosion or physical damage to wiring harnesses or circuit boards, or if the error appears intermittently and cannot be reliably reproduced.