LG Oven Error Code Displayed — Troubleshooting Guide

When your LG oven displays an error code, the control board has detected a specific fault condition and is communicating which system has failed. LG ranges and wall ovens use alphanumeric codes (typically "F" followed by a number) that map to specific sensor, element, or control failures. Understanding these codes helps you determine whether the issue is a simple sensor replacement or requires more significant repair.

LG Oven Error Code Reference

Temperature Sensor Codes

F9 — Open Oven Temperature Sensor Circuit The most common LG oven error. The thermistor sensor or its wiring has an open circuit — the ERC cannot read oven temperature.

• Immediate action: Oven may shut down heating as a safety measure
• Diagnosis: Test sensor resistance (should be ~1080 ohms at 70F). If open (infinity), check wiring first, then replace sensor
• Common cause: Wire harness break near where it enters the oven cavity (heat degrades insulation)
• Parts: $20–$50 (sensor)
• Repair cost: $150–$250

F10 — Shorted Oven Temperature Sensor / Runaway Temperature The sensor reads abnormally low resistance (high temperature) or actual oven temperature exceeded safe limits. This is a critical safety code.

• Immediate action: Oven shuts down all elements immediately
• Diagnosis: If oven was cool when code appeared: sensor is shorted. If oven was extremely hot: genuine overtemp occurred (check element relay stuck closed, or failed sensor giving false low reading causing over-firing)
• Common cause: Sensor shorted internally, or relay welded causing runaway heating
• Parts: $20–$50 (sensor), $150–$400 (control board if relay welded)
• Repair cost: $150–$550 depending on cause

Element and Relay Codes

F1 — Control Board Internal Fault The ERC's microcontroller detected an internal error (corrupted memory, failed self-test, or stuck relay).

• Immediate action: Press Clear/Off. If code returns after power cycle, board needs replacement
• Diagnosis: Power cycle (unplug 5 min). If F1 persists immediately on power restore: board failure confirmed
• Common cause: Aging control board, power surge damage, thermal stress from years above oven
• Parts: $150–$400 (ERC)
• Repair cost: $300–$550

F3 — Open Bake Element / Bake Circuit Failure The ERC attempted to activate the bake element but detected no current flow (element burned out or wire disconnected).

• Diagnosis: Test bake element continuity (disconnect leads, measure across terminals)
• Common cause: Burned-out bottom bake element — most common single component failure in ovens
• Parts: $30–$80 (bake element)
• Repair cost: $150–$280

F4 — Open Broil Element / Broil Circuit Failure Same as F3 but for the broil (top) element.

• Parts: $30–$80 (broil element)
• Repair cost: $150–$280

F5 — Door Latch Fault The latch motor activated but the position switch did not confirm lock/unlock within the expected time.

• Diagnosis: Latch motor gear stripped, switch failed, or wiring issue
• Parts: $40–$80 (latch assembly)
• Repair cost: $180–$300

Communication and System Codes

F7 — Stuck Key / Touchpad Fault A touchpad button appears continuously pressed to the control board.

• Immediate action: Press Clear/Off. If code persists, unplug and check for moisture on touchpad
• Diagnosis: Usually moisture in touchpad membrane or a failed key. Disconnect touchpad ribbon cable — if F7 clears with cable disconnected, touchpad needs replacement. If F7 persists with cable disconnected, board fault
• Parts: $80–$200 (touchpad) or $150–$400 (board)
• Repair cost: $200–$550

F11 — Communication Error (ThinQ-enabled models) The Wi-Fi module and main ERC have lost communication.

• Diagnosis: Usually not critical for cooking — oven functions normally, just smart features offline
• Fix: Power cycle. If persists, check Wi-Fi module connector. May require module reset or replacement
• Parts: $40–$80 (Wi-Fi module)
• Repair cost: $120–$200

LG-Specific Convection Codes

CF — Convection Fan Fault (some LG models) The ProBake convection fan is not spinning at expected RPM or is drawing excessive current.

• Diagnosis: Check fan for obstruction (food debris), test motor, verify wiring
• Parts: $40–$80 (fan motor)
• Repair cost: $200–$350

How to Clear LG Oven Error Codes

1. Press Clear/Off — this dismisses the alarm and attempts to reset the oven to standby
2. If code returns immediately: The fault condition still exists — repair needed
3. If code cleared but returns during next use: Intermittent fault — diagnosis needed to find root cause
4. Power cycle (unplug 5 min): Clears board memory. If code returns on power restore, hardware failure confirmed
5. After repair: Run a bake test to confirm code does not return

When Error Codes Mean Immediate Action

LG Smart Diagnosis for Error Codes

Before scheduling service, use LG's built-in diagnostics:

1. ThinQ App (Wi-Fi models): Open app, select range, run Smart Diagnosis — provides specific failure information
2. Phone Audio Method: Call LG at 1-800-243-0000, select Smart Diagnosis option, hold phone near control panel when prompted for audio data transmission
3. Smart Diagnosis can sometimes identify intermittent issues that don't trigger persistent codes

Prevention Tips

• Use a surge protector on the range circuit — power surges are the leading cause of F1 (board failure)
• Clean temperature sensor annually — grease buildup insulates the sensor, causing inaccurate readings
• Keep oven vent clear — blocked vents cause overheating that triggers F10
• Address intermittent codes immediately — they often indicate progressive component failure

FAQ

Q: My LG oven shows an error code then clears itself — do I need repair? If the code appears during specific conditions (high temperature, long bake, specific mode) and clears when conditions change, you have an intermittent fault. It will worsen. Schedule diagnosis before it becomes permanent.

Q: Can I still cook with an error code displayed? Depends on the code. F9/F3/F4 mean reduced functionality (some modes may still work). F1/F10 mean the oven should not be used until repaired. F5 only affects self-clean.

Q: My LG oven shows error code after power outage — is it damaged? Power outages can corrupt ERC memory, triggering F1. Power cycle (unplug 5 min). If code clears and doesn't return during normal cooking, no damage occurred. If persistent, the power surge during restoration damaged the board.

---

Error codes tell you exactly what failed. Our technicians decode LG error codes and carry sensors, elements, and control boards for same-visit resolution. Schedule a diagnostic →