Step-by-Step DIY Fix Guide
- SAFETY: No electrical hazard for probe connection checks.
- If the meat probe is inserted in food, ensure the probe plug is fully seated in the oven wall socket — push firmly until it clicks.
- If you are not using the meat probe, cancel the current cooking mode and start a standard bake cycle instead of a probe cycle.
- Inspect the probe cable for any kinks or visible damage near the plug.
- If F18 occurs with the probe fully inserted and undamaged, the probe thermistor has failed — replace the probe.
If the warning comes back after restart
- If the warning returns immediately after a clean restart, the sensor or wiring path becomes more likely than a one-time glitch.
- F18 persists with a new probe fully inserted — probe socket in the oven wall may be damaged
What This Error Means
Error F18 on your LG oven means: The meat probe (temperature probe) is either not connected correctly, has been left in its storage holder while a probe-required mode is active, or has failed. The range's self-diagnostic system has detected this condition.
The most frequent cause is meat probe not fully inserted into the probe socket inside the oven cavity. Work through the causes and fix steps below in order — many LG oven errors are resolved without a service call.
Error F18 is DIY-safe. No tools are required and the fix typically takes under 10 minutes. Follow all steps in sequence.
The oven will not complete the affected function until the condition is resolved. Work through all steps before contacting LG Support.
What users usually notice before this code
LG oven warnings like this often appear after interrupted heating, control resets, sensor mismatch, or a fault that returns during warm-up rather than during a stable cook cycle.
Common misdiagnoses
- Assuming the display code proves one exact failed part before the safe first checks are done.
- Treating a sensor-related warning as a guaranteed board failure before checking the simpler model-family causes first.
Most Likely Cause by Symptom
The LG oven may stop, pause, or refuse to complete the cycle normally.
Likely cause: Meat probe not fully inserted into the probe socket inside the oven cavity
Check first: SAFETY: No electrical hazard for probe connection checks.
Common Causes
- Meat probe not fully inserted into the probe socket inside the oven cavity
- Meat probe used in a cycle that does not require a probe — disconnected during a probe-required mode
- Meat probe cable damaged — bent at the socket end or the cable is kinked
- Meat probe sensor has failed — thermistor inside the probe tip is open-circuited
What Not to Do
- Do not immerse the meat probe in water for cleaning — the thermistor sensor at the tip is not waterproof
Model and Display Variation Notes
Model-family notes
- LG oven display wording and code formats can vary by series.
- If your model behaves differently, check the owner manual before trying any deeper maintenance step.
Display and panel differences
- Panel wording can vary by series, so confirm the exact code pattern before buying parts.
Parts, Tools and Service Options
Common parts
- Meat probe/temperature probe if probe sensor has failed ($15–$40)
Manual and model check
Check your exact model and manual before ordering any LG oven parts.
Suggestions in this section are organized to support the troubleshooting flow first. Any future affiliate relationships should be disclosed clearly.
When Not to Keep Troubleshooting
F18 persists with a new probe fully inserted — probe socket in the oven wall may be damaged
How to Prevent It Recurring
- Store the meat probe in the oven compartment storage drawer when not in use — do not leave it plugged into the oven socket during standard baking
Related Error Codes
F1
The upper oven temperature sensor (thermistor) is reading an open circuit — its resistance is outside the valid range, meaning the oven cannot monitor temperature in the upper cavity.
F3
The oven's control panel has detected a faulty key or touch sensor — a button is either stuck in a continuously pressed state, or a touch pad sensor is malfunctioning.
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When not to keep pushing DIY troubleshooting
Use the code page for one careful first pass, then stop if the same warning returns or the appliance still cannot get back to normal operation.
Extra notes
- This page is based on LG support material and stays conservative where model-specific guidance may vary.
- The goal is to help you identify safe first checks before you move into parts, service, or model-specific manual lookup.
Source and model notes
Last reviewed: 2026-04-08
Based on: Based on LG support material and edited into consumer-safe guidance for the exact code family on this page.
Model coverage note: LG oven code meanings can vary by series, control panel, and model family, so use this page as a safe starting point rather than a replacement for the model-specific manual.
Important: FixThisError is an independent guide, not the manufacturer. Use your model-specific manual when the panel wording or behavior differs.
Always disconnect power before inspecting appliances. If unsure, contact a licensed appliance technician.