An F3 error is almost always caused by a faulty oven temperature sensor probe that has internally shorted. To fix it, unplug the oven and test the sensor with a multimeter. It should read approximately 1090 ohms at room temperature; if it is significantly lower, replace the sensor.
An F3 on your LG oven kills your cooking right now, and honestly that's frustrating, but don't panic. It's almost always the probe itself, not the control board. A $20-30 part and an hour of your Saturday usually fixes this completely. Ignore it though and you're risking a runaway oven that overshoots temp badly, and that's genuinely dangerous.
Phillips #2 screwdriver, Multimeter with ohms/resistance mode
What Does the F3 Code Mean?
Think of the sensor as your oven's thermometer. When it dies, the control board can't read the temp, so it shuts everything down for safety and throws F3. Homeowners always assume they need an expensive new board, but honestly nine times out of ten it's just the probe. I've swapped dozens of these things. It's a high-success DIY fix with a cheap part.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Failed oven temperature sensor probe75%
Wiring harness damage or shorts15%
Main control board (PCB) fault10%
Symptoms You May Notice
F3 displayed on control panel
Oven will not heat at all
Oven temperature is wildly inaccurate (burns food or never reaches set temp)
Oven heats then shuts off with F3 mid-cycle
Broil works but bake does not (or vice versa)
Can you reset a Lg oven to clear the F3 code?
To clear the F3 logic from the board memory, flip your circuit breaker for at least a full minute. Once you restore power, press the Clear or Off button. If the sensor is still faulty, the code will likely pop back up the moment you try to start a bake cycle. If the code stays gone after a reset but the oven still cooks unevenly, that is your sign to test the sensor resistance regardless.
Tools Required for Diagnosis
Phillips #2 screwdriverMultimeter with ohms/resistance modeFlashlight or headlamp1/4 inch nut driver or socket (for back panel screws)Needle-nose pliers (for harness connector clips)
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
ComponentComponent Under Test
Expected Range1050–1100 ohms
ConditionIf Open (OL) or infinite, replace component.
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
Part Name
OEM Number
Estimated Price
RTD Oven Temperature SensorEBG61106803 · $15–$30
EBG61106803
$15 – $30
Frequently Asked Questions
What is the correct resistance for an LG oven RTD sensor?
For almost every modern LG range, you're looking for about 1090 ohms at room temperature, roughly 70 degrees Fahrenheit. As the oven heats up, that resistance climbs proportionally. If your meter shows anything below 900 or above 1200 while the oven's cold, the sensor's sending bad data to the board. I usually tell people that if it's off by more than 50 ohms from the target, just swap it. The part's cheap enough that it's not worth the guesswork, honestly.
How long does an LG oven temperature sensor last?
Most of these sensors live about a decade under normal use, but the self-clean cycle is a known killer. You're cranking that oven up to 900 degrees, and that puts serious thermal stress on the internal wire inside the probe. If you use self-clean a lot, don't be surprised if you're swapping this sensor every 5 or 6 years. It's a cheap part, usually $20-30, so I keep a spare in my truck for common LG models. Way less downtime for the customer when I've already got it on me.
Can I verify the repair by recalibrating the oven temperature?
Yeah, always do a calibration check after a sensor swap. Put a good oven thermometer on the middle rack and set the oven to 350. Let it run for at least 20 minutes so the walls soak up heat and the temp stabilizes. If the thermometer's within 15 degrees of the display, you're good. If it's off, LG lets you adjust the temp offset through the Settings menu, usually up to plus or minus 35 degrees. It's listed in the manual under temperature calibration and takes about 30 seconds.
Is the RTD sensor the same as the oven thermostat?
Not the same thing. Old ovens used a bulb-style thermostat that basically acted like a simple on/off switch. Modern LG ovens use this RTD sensor, which works more like a continuous digital thermometer, sending constant resistance data to the control board so it can make precise adjustments on the fly. That's why the F3 code is pretty sensitive. The board notices even small deviations from expected resistance values and shuts things down fast. It's actually a solid safety design, just annoying when the cheap part finally gives out.
My LG oven shows F3 but still heats. Is it safe to use?
Don't use it. Seriously. If F3 is on screen, the board's already flagged that it can't trust the temperature data it's getting. Even if it seems to heat normally, it's lost the ability to cut power accurately when it hits your target temp. That means it can overshoot badly, way hotter than you set it, and that's a real fire risk. Flip the breaker off until you get that probe swapped out. I know it's inconvenient but it's genuinely not worth gambling on.