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Source-backed error-code guide

Reviewed

LG Microwave F3 Error Code

F3 is a touch-control-area error on the LG microwave/lightwave models covered by the manufacturer guidance. LG recommends cleaning only the exterior touch-button area and then checking the display again. If F3 persists after one power reset, professional inspection is the safe next step.

Applies to LG microwave or lightwave oven with an applicable electronic display

What the appliance detected

Detected condition

LG says an F3 error on applicable lightwave ovens can occur when foreign substances are around the touch-button panel.

What may contribute

Possible causes

  • Food residue, grease, moisture, or another foreign substance may be affecting the exterior touch-button area.
  • A temporary control error may have occurred.
  • If the code persists, the keypad, control electronics, internal wiring, or another component may require professional diagnosis.

Start conservatively

Safe preliminary checks

Work in order and stop whenever a step is not supported by the documentation for your model.

  1. Record F3 and confirm the LG model

    • Photograph the complete display before clearing it and record the full model number from the appliance label.
    • Use the model-specific LG manual or support page to confirm that F3 has the same meaning for your microwave or lightwave oven.

  2. Clean only the exterior touch-button panel

    • Disconnect power and let the appliance cool if it was recently used.
    • LG says foreign substances around the touch-button panel can trigger F3. Wipe the accessible exterior control surface using the cleaning method allowed by the model manual, then let it dry completely.
    • Do not pry up buttons, flood seams with cleaner, spray liquid into openings, remove trim, or open the control panel.

  3. Try one LG-documented power reset

    • If there is no smoke, burning odor, arcing, visible damage, wet electrical condition, or repeated breaker trip, disconnect power once and reconnect it after the brief power-off interval described by LG.
    • If F3 returns, stop using the microwave and request service rather than repeating resets.

Actions not recommended

  • Do not remove the outer cabinet, control panel, waveguide cover, vent housing, or any microwave service panel.
  • Do not touch or test the high-voltage capacitor, transformer, inverter, magnetron, internal fuses, relays, sensors, door-interlock wiring, or control boards. Dangerous voltage can remain after power is disconnected.
  • Do not perform live-voltage, resistance, continuity, capacitor-discharge, or internal connector testing as a homeowner troubleshooting step.
  • Do not bypass, bridge, tape, defeat, or adjust a door-interlock switch, and do not operate a microwave with a damaged or misaligned door.
  • Do not replace a keypad, sensor, control board, relay, switch, or wiring harness from a display message alone.

When to stop and request service

  • Request qualified microwave service if F3 returns after the exterior panel is clean and dry and after one power reset.
  • Leave power disconnected and seek service immediately for smoke, burning odor, repeated arcing, abnormal overheating, a damaged door, visible wiring damage, liquid inside electrical openings, or repeated breaker trips.

Documented source

Official information reviewed

Our summary is based on manufacturer support material and stays within the limits of that material.

Source reviewed by Appliance Help HQ: September 24, 2026.

Appliance Help HQ is an independent informational site and is not affiliated with or endorsed by LG.

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