LG Oven Error Code F5

LG Oven F5 Error — What It Means and Why It Happens

The LG oven F5 error code typically indicates a fault in the oven’s temperature sensing or control/communication system. On many LG electric ranges and wall ovens the F5 code is reported when the control board detects inconsistent temperature feedback, a short or open circuit in the temperature sensor (thermistor/RTD), or failed communication between the user interface and the main electronic control board. Symptoms can include the oven refusing to heat, shutting off unexpectedly, wildly inaccurate temperature readings, extended cooking times, or an error message that prevents normal operation. Left unresolved, the problem can lead to unevenly cooked food, wasted energy, and in rare cases safety risks (overheating or uncontrolled heating) if the thermostat or safety cutouts fail to operate properly.

Common Causes

• Faulty temperature sensor (NTC thermistor / RTD) giving incorrect resistance readings
• Loose or damaged wiring harness/connector between sensor and main board
• Defective electronic control board (main PCB / EOC) or failed components on the board
• Malfunctioning touchpad or user interface sending incorrect commands
• Thermostat or thermal fuse/limit switch tripped or failed
• Power surges or intermittent power causing communication errors
• Cooling fan or relay failure causing overheating/protection triggers
• Corrosion or moisture in connectors or sensor terminals

Troubleshooting Steps

1. Power cycle the oven: Turn the range off at the breaker for 60 seconds and restore power. Sometimes transient faults clear and the F5 message will reset.
2. Note additional symptoms: Does the oven fail to heat, display other error codes, or make unusual noises? Documenting behavior helps pinpoint the component at fault.
3. Inspect visible wiring and connectors: With power off, check the oven sensor connector, harness, and the main control wiring for burns, loose pins, or corrosion.
4. Test the oven temperature sensor: Remove the sensor probe and measure resistance with a multimeter at room temperature (typical NTC sensors read ~1000–1100 ohms at 25°C for many models — check your model’s spec). An open circuit or wildly out-of-spec reading suggests replacement.
5. Swap or reseat the sensor connector: If the sensor reads correctly but the code persists, reseat connectors and inspect harness continuity. Replace wiring if damaged.
6. Check thermal fuse/limit switch: Use a multimeter to test for continuity. A blown thermal fuse will often cause protection faults and must be replaced.
7. Reset or recalibrate the control (if available): Some LG ovens have diagnostic modes or calibration options. Consult your model’s service manual to run diagnostics — this can reveal sensor faults or EEPROM errors.
8. Inspect the control board: Look for burnt components, swollen capacitors, or visible damage. If the board shows damage or diagnostics point to board failure, replacement is usually necessary.
9. Replace suspect parts one at a time: Replace the temperature sensor first (most common & inexpensive). If the issue continues, replace the wiring harness or control board as diagnosed.
10. When in doubt, call a certified technician: If tests point to control-board repairs, or the oven needs live-voltage work, arrange professional service to avoid shock, fire, or warranty voiding.

Maintenance / Prevention Tips

• Keep oven interior and sensor area clean to avoid debris affecting sensor readings.
• Avoid using harsh liquids or sprays near the control panel to prevent moisture intrusion.
• Check and reseat connectors during routine cleaning or repairs to prevent loose connections.
• Use a surge protector or whole-home surge suppression to reduce control board damage from spikes.
• Replace the oven sensor at first sign of inconsistent temperatures or after 5–8 years as preventative maintenance.
• Inspect the wiring harness periodically for chafing or heat damage, especially around heating elements.
• Run a self-clean or high-heat cycle sparingly and follow manufacturer guidance to avoid overheating sensors or boards.
• Keep vents and cooling fans free of grease and dust to maintain proper cooling of electronics.
• Use manufacturer-recommended replacement parts to preserve compatibility and safety features.
• Record error codes and conditions when they occur — that history helps technicians find intermittent faults faster.
• Schedule professional maintenance if your oven is older than 8–10 years to catch aging electronics early.

FAQs

Conclusion & Safety Notice

The LG F5 oven error most commonly points to sensor or control communication problems that affect cooking accuracy and safe operation. For simple checks (power cycle, visual wire inspection, sensor resistance test) a confident DIYer can often identify the issue, but any troubleshooting requiring live-voltage probing, control-board replacement, or major disassembly should be handled by a licensed appliance technician. Working on high-voltage components without proper training can cause electric shock, fire, or further damage and may void warranties.

If you’ve run basic tests and the F5 persists, stop using the oven and contact LG support or a certified repair service. Replacing the correct part after proper diagnosis is the fastest way to restore safe, accurate oven performance.