LG Oven Error Code F4
F4 is the companion code to F1: the control saw an oven sensor circuit stay open after cooking started. On double-oven models it is usually the lower oven sensor; on some control platforms it is simply how the same sensor-open fault is reported.
Also shown as: F-4
Common causes
- Second (lower) oven temperature sensor has failed open
- Sensor connector worked loose from vibration or heat
- Sensor wiring harness open or broken
- Failed electronic control board sensor circuit
What to check, in order
- Press CLEAR/OFF, turn the breaker off for a few minutes, then restore power and retry the oven that showed the code.
- On a double oven, confirm which cavity was running when the code appeared; F4 covers the sensor circuit the control pairs with F1, most often the lower oven.
- With power off and the cavity cool, check the sensor probe mounting and its connector at the back of the oven.
- Test the sensor with a multimeter; roughly 1,080 ohms at room temperature is normal, while an open reading means replacement.
- If the sensor and harness check out, the control board is the likely fault and needs a technician.
Clear the code and test
- Fix what the checks above found first. Clearing the code without fixing the cause only brings it back.
- Plug the appliance back in and restore its water supply if it has one.
- Run the shortest programme and watch the point where the code appeared before.
- If the programme finishes with no code, the fault is cleared. If the code returns, write it down before calling a technician — it speeds up the diagnosis.
When to call a professional
Most cases are solved by the checks above. Book a technician if any of these apply:
- The code comes back after you have run the checks and a test cycle.
- You smell burning, see sparks or scorch marks, or the breaker trips.
- Water is leaking and you cannot stop it at the tap.
- The fix needs panels opened beyond what your manual describes, or a part tested with a meter, and you are not set up for that.
When you call, give the brand, the code F4, your model number (on a label inside the door or on the back) and the checks you already ran. It shortens the visit.
Parts that may be involved
Oven temperature sensorSensor wiring harnessElectronic control board
Parts are model-specific. Find your model number first — usually on a label inside the door, on the door frame or on the back — and match the part to that number before ordering.
Questions people ask about F4
What does F4 mean on a LG oven?
F4 means: Oven sensor error: second sensor circuit is open. F4 is the companion code to F1: the control saw an oven sensor circuit stay open after cooking started. On double-oven models it is usually the lower oven sensor; on some control platforms it is simply how the same sensor-open fault is reported.
Can I fix LG F4 myself?
Start yourself: the checks on this page cover the causes you can reach without opening the machine up. If they point to a faulty part, testing or replacing it is usually a technician job.
How do I clear LG F4?
Fix the cause first — clearing the code on its own brings it straight back. Then restore power and water, run the shortest programme, and watch the stage where the code appeared. If the programme finishes with no code, it is cleared.
Sources checked
- LG Help Library: washing machine error codes
- PartsTown Resource Center: LG washing machine troubleshooting codes
The meaning and checks for this code were checked against the sources above in November 2026. Codes vary by model and region; if your manual lists a different meaning for your exact model, follow the manual.