LG Microwave Error F3
⚡ Quick Answer: The F3 error on LG microwaves indicates a malfunction in the temperature sensing system or control panel circuitry. This error often causes the microw... ✅ DIY Fixable
What Does Error F3 Mean?
The F3 error on LG microwaves indicates a malfunction in the temperature sensing system or control panel circuitry. This error often causes the microwave to stop heating and may display during startup or cooking. If the F3 error persists, it’s essential to check for foreign substances on the touch panel or potential issues with the temperature sensor.
Common Symptoms:
- F3 error displayed on the microwave screen at startup or during cooking
- Microwave may stop heating or cease operation when the error appears
- Error persists after normal operation without clearing
Possible Causes
- Foreign substances or contamination around touch button panel (medium)
- Faulty or malfunctioning temperature sensor (thermistor) (medium)
How to Fix Error F3
DIY Fix Clean and inspect control panel
- Unplug the microwave from power.
- Wipe the touch button panel with a soft, dry cloth to remove possible contamination.
- Plug back in and check if the F3 error clears.
DIY Fix Perform power reset
- Unplug the microwave from the electrical outlet for at least 5–10 minutes.
- Plug it back in and test operation to see if error persists.
Technician Only Inspect and test temperature sensor and wiring
- Disconnect power and remove microwave cover.
- Locate the temperature sensor/thermistor and check wiring integrity.
- Test sensor resistance with a multimeter; replace if out of specification.
- Check and secure or replace damaged wiring harnesses.
Parts needed: Temperature sensor/thermistor, Wiring harness/connectors
Technician Only Inspect control board and touch panel circuitry
- Visually inspect control board for burnt components or damage.
- Test control panel and related circuits for proper operation.
- Replace control board or panel if diagnostics indicate failure.
Parts needed: Control board, Touch/control panel assembly
- If the F3 error persists after basic cleaning and reset attempts.
- If unusual smells, smoke, or signs of electrical damage are observed.
- If you are not comfortable performing internal diagnostics involving high voltage components.
Next step
Choose the next step for F3
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Temperature Sensor
Monitors the internal temperature to ensure correct operation and prevent overheating.
- Typical part-only price
- $15 - $35
- DIY difficulty
- Easy
- Estimated time
- 15-30 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
Thermistor
Measures precise temperature changes and sends resistance feedback to the control board.
Wiring Harness
Connects controls, sensors, motors, and other electrical components inside the appliance.
Main Control Board
The central brain of the appliance that controls all components, cycles, and timings.
Model-compatible Microwave parts
Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.
Technical Specifications
| note | The previous model-independent part specification was removed. Verify the full model number and diagnosis in the manufacturer's official parts catalog before ordering. |
|---|---|
| part_number | None |
Common Questions
What does F3 error mean on LG microwave?
F3 indicates a malfunction in the temperature sensing system, causing heating failure.
Can I fix LG microwave F3 error myself?
Yes, try cleaning the control panel and performing a power reset.
How much does it cost to fix F3 error?
Repair costs for the F3 error are typically moderate.
When should I call a technician for F3?
Call a technician if the error persists after basic troubleshooting or if you notice unusual smells.
Sources & References
- LG Microwave - Troubleshooting an F3 Error (official)
Data last verified: 2026-07-31
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