LG Range & Oven Error Codes: Complete 2026 Guide (F1–F13 and All Fault Codes)

Universal Reset Procedure for LG Range Error Codes

Every LG range error code should go through the same two-step reset before any diagnostic work is done:

1. Press CLEAR/OFF (or CANCEL). This key clears the displayed error and returns the panel to standby. If the code clears and does not return during the next cooking cycle, it was a transient event — no component has failed.
2. Circuit breaker reset. If CLEAR/OFF does not clear the code, or if the code reappears within minutes, turn the circuit breaker for the range to the OFF position for 30 seconds. This fully discharges the control board capacitors. Restore power and wait 2 minutes before operating the range.

If the error code reappears after a circuit breaker reset during normal use, a physical component has failed. The reset will not repair it — but it confirms the fault is genuine and not a one-time anomaly. That information alone saves a diagnostic service call in many cases.

Temperature Sensor Codes: F1, F2, F4, F5

Four LG range error codes are directly tied to the oven temperature sensor (thermistor). The thermistor is a small probe mounted in the upper rear interior wall of the oven cavity — the same physical location on virtually every LG range model manufactured since 2010. Understanding which code maps to which failure mode tells you exactly what to test first.

Sensor resistance baseline: At room temperature (~72°F / 22°C), a healthy LG oven thermistor reads approximately 1,080–1,090 ohms with a multimeter. To test: unplug the range, remove the two mounting screws holding the sensor probe to the oven rear wall, pull the probe 2–3 inches out through the cavity, and test resistance at the connector. Any reading significantly outside the 1,080–1,090 ohm range confirms sensor failure.

F1 — Upper Oven Thermistor Open Circuit

F1 indicates the upper oven temperature sensor has an open circuit — the resistance reading is infinite, meaning the sensor wire has broken or the thermistor element itself has burned out. With no temperature signal from the sensor, the control board will not allow the oven to operate.

Diagnosis: Remove the oven sensor (two screws, rear interior wall, upper cavity). Test resistance at the sensor's wire connector: if your multimeter shows "OL" or infinite resistance, the sensor element has failed. If the sensor tests correctly at the plug end but shows infinite resistance at the control board connector on the opposite end of the wiring harness, the harness itself has a break — check for any pinch points near the door hinge area.

Fix: Oven temperature sensor replacement — $20–50 for the part on most LRE and LRG models, approximately 15 minutes to swap with a screwdriver. All-in repair cost with a technician: $120–200. This is the most straightforward DIY repair in LG range error code diagnostics.

F2 — Upper Oven Runaway Temperature (Safety-Critical)

F2 is the most serious error code an LG range can display. It means the oven temperature has climbed significantly above the setpoint and the control board cannot stop it — the bake or broil heating element is being held energized by a failed relay even when the control board is commanding it off.

Safety action required: Press CLEAR/OFF immediately. If the code does not clear, or if the oven feels unusually hot above the setpoint, shut off the circuit breaker. Do not open the oven door while it may be overheating — the burst of superheated air presents a burn risk. Do not use the range again until a technician has inspected the temperature sensor, relay board, and main control board.

Root causes in order of frequency: (1) Failed thermistor reading near-zero ohms — the board interprets this as "oven is ice cold" and commands maximum heat indefinitely. (2) Welded relay on the control board — a relay contact has fused in the closed position, keeping the element permanently energized regardless of the board's commands. (3) Failed main control board — rare, but possible if the relay board has already been replaced without resolving the code.

Repair cost: $200–600 depending on root cause. A thermistor-caused F2 resolves for $120–200 (sensor replacement). A failed relay board runs $250–450 in parts plus labor.

F4 and F5 — Lower Oven Thermistor (Double-Oven Models)

F4 and F5 are the lower oven equivalents of F1 and F2, present specifically on LG double-oven ranges with independently controlled upper and lower cavities.

• F4 — Lower Thermistor Open Circuit: Same failure mode as F1, but the sensor is in the lower oven cavity. Test resistance at the lower sensor connector — target is ~1,080–1,090 ohms at room temperature. Sensor replacement cost: $20–50 in parts. Single-oven ranges do not display F4.
• F5 — Lower Thermistor Short Circuit: The lower oven sensor is reading near-zero ohms rather than the expected 1,080 ohms — a short circuit in the sensor element or wiring. A shorted thermistor makes the control board believe the oven is far hotter than it actually is, causing the board to cut heat prematurely. Sensor replacement resolves F5 in the same way as F4.

On single-oven LG ranges, F4 and F5 are not active fault codes — only F1 (open) and F2 (runaway) apply to the single oven cavity.

Heating Failure Codes: F6 and F9

F9 — Oven Not Reaching Temperature (Most Common LG Range Code)

F9 is by far the most frequently reported LG range error code in the field. It triggers when the oven temperature fails to increase by at least 5°F (3°C) within the first few minutes of a cook cycle. The control board commanded the heating system on — but the cavity is not warming. The cause differs meaningfully between electric and gas range platforms:

Electric ranges (LRE, LSE series): The bake element has failed. Visually inspect the element for cracks, blistering, or burn marks — a failed element almost always shows visible damage. If no damage is visible, test with a multimeter: a healthy bake element reads 15–30 ohms; an open circuit (OL / infinite resistance) confirms failure. Bake element replacement: $30–60 in parts. This is a beginner-level DIY repair — unplug the range, remove 2 screws holding the element to the oven rear wall, disconnect 2 wire connectors, install the new element, reconnect, test.

Gas ranges (LRG, LSG series): The oven igniter is drawing insufficient current to fully open the gas safety valve. A healthy igniter must draw approximately 3.2–3.6 amperes to open the spring-loaded gas valve. An aging igniter may draw only 2.0–2.8 amps — still enough to glow visibly, but not enough to open the valve. This is why a glowing igniter that takes more than 60–90 seconds to light the burner is a failing igniter, not a working one. Gas range igniter replacement: $40–80 in parts; $150–280 all-in with labor.

F9 on Broil setting only: If F9 appears exclusively when using the Broil setting — normal Bake works fine — the broil element (top of cavity) has failed separately from the bake element (bottom). Test the broil element with a multimeter using the same 15–30 ohm target.

F6 — Upper Oven Over-Temperature Alarm

F6 indicates the upper oven temperature exceeded its safe operating threshold — distinct from F2 in that F6 is a threshold alarm that may or may not indicate a sustained runaway condition. F6 can appear transiently when the oven is used at maximum temperature for an extended period, or when a self-clean cycle temperature temporarily exceeds the sensor alarm point. It is also associated on some LG models with a defective thermal cutout (a one-shot safety fuse on the bake circuit) that has tripped prematurely at a lower-than-rated temperature.

First step: a 30-second breaker reset followed by a normal bake test cycle. If F6 recurs during normal cooking at standard temperatures, have the thermistor resistance and thermal cutout continuity tested before assuming the control board is at fault.

Mechanical and Physical Codes: F7, F8, F10, F12

F10 — Upper Door Lock Error (Self-Clean Cycle)

F10 appears when the oven door lock mechanism fails to complete the locking sequence required for a self-clean cycle. LG ranges automatically lock the door at the start of self-clean because cavity temperatures reach approximately 900°F (482°C) — the door cannot be opened safely during this process. F10 means the lock motor did not drive the latch to the fully-locked position within the expected time window.

DIY check first: Press CLEAR/OFF to cancel self-clean. Manually open and firmly close the oven door, ensuring it latches securely with no bounce. Check for any food debris or buildup around the door frame or latch receptor that might prevent full mechanical engagement. Start self-clean again. If F10 returns immediately, the door lock motor assembly has worn and needs replacement.

Repair: Door lock motor assembly replacement — $60–120 in parts depending on model, $200–300 all-in with a technician. On most LG freestanding ranges, the lock assembly is accessible from the top-rear of the range after removing the rear panel. Some slide-in models require partial disassembly of the door inner panel.

F12 — Lower Door Lock Error (Double-Oven Models)

F12 is the lower oven equivalent of F10, found only on LG double-oven ranges where the lower cavity has its own independently locking door. Same diagnostic approach as F10 — check mechanical latch engagement first, replace the lower door lock assembly if latch is clear but F12 returns.

F7 — Upper Convection Fan Error

F7 indicates the convection fan motor in the upper oven has stopped operating or the control board is not receiving the expected feedback signal. The convection fan circulates heated air evenly through the oven cavity, enabling convection bake and convection roast modes. F7 does not disable the oven's heating elements — standard bake and broil will function — but all convection-dependent cooking modes will fail.

Initial inspection: With the range unplugged and the oven cavity fully cooled, look through the rear interior oven wall at the convection fan blade. Check for grease accumulation, a baked-on food obstruction, or any foreign object. Attempt to spin the blade manually — resistance or stiff rotation indicates a failed motor bearing. Fan motor replacement: $80–140 in parts, $240–380 all-in with a technician.

F8 — Meat Probe (Temperature Probe) Error

F8 means the oven temperature probe — the metal sensor used to monitor internal food temperature during probe-guided cooking — is absent, not properly seated in its jack, or has failed. Critically, F8 only appears when the range is in Probe cooking mode. It will not appear during standard bake or broil cycles.

If the probe is not in use: The probe input jack inside the oven cavity may have a bent contact pin, debris, or a foreign material causing a false short circuit. Inspect the jack with a flashlight and clear any debris. Run a normal bake cycle (not probe mode) to confirm the range otherwise functions correctly.

If using the probe: Confirm the probe plug is fully and firmly seated in the oven jack. If F8 persists with the probe fully inserted, the probe cable or probe tip has failed. A replacement probe is a user-replaceable part — $25–60 depending on model — requiring no tools or disassembly.

Control Board and Communication Codes: F3, F11, F13

F3 — Touchpad Sensor Key Error

F3 triggers when the control board detects that one or more keypad buttons has been continuously active for more than 60 seconds — indicating a stuck, shorted, or contaminated key contact. The most common scenario in the field is a liquid spill (cooking spray, steam condensation, cooking liquid overflow) soaking into the membrane switch layer under the glass or plastic control panel surface.

First response: Press CLEAR/OFF and inspect the panel surface for sticky residue or visible spill deposits. Try pressing each button individually and note whether any feel mechanically stuck or produce no click. A 30-second circuit breaker reset is the next step. If F3 clears after the reset and does not recur during normal cooking, the event was transient. If F3 returns as soon as the range is powered on — particularly if a specific button area appears stuck — the keypad membrane switch or touchpad control board has a permanently shorted contact and needs replacement.

Parts: Keypad membrane switch panels: $80–150 on most LRE/LRG models. Integrated touchpad + display assemblies (where both are a single unit): $200–350. Labor: $80–120 additional.

F11 — Communication Error Between Control Boards

F11 means the range's main control board (located behind the rear panel, near the bake element wiring) has lost communication with the display and user interface board (located behind the front control panel). These two boards communicate continuously during operation; F11 signals that they have stopped talking to each other.

Power surges, brownouts, and utility events are the most common trigger for F11. Always perform a 30-second circuit breaker reset first — it resolves a significant share of F11 occurrences that were triggered by transient power events. If F11 returns after two resets during normal cooking, the wiring harness connecting the boards or one of the boards itself has failed. Identifying which board is at fault typically requires a service technician with a test harness. Main control board replacement: $250–450 in parts; all-in $380–580 with labor.

F13 — Lower Oven Runaway Temperature (Double-Oven Models)

F13 is the lower oven equivalent of F2 — a runaway temperature safety event in the lower cavity of a double-oven range. Apply the same safety protocol as F2: press CLEAR/OFF immediately, shut off the circuit breaker if the code persists or the oven feels abnormally hot, and do not operate the range until a technician has inspected the lower oven sensor, relay board, and main control board.

Gas vs. Electric: Code Differences That Matter in the Field

Most LG range error codes apply identically to both electric and gas models. The one important exception is F9 — the most common code — where the root cause and repair are platform-specific:

Gas ranges also exhibit one additional condition that does not produce an F-code but generates the most service calls: surface burner igniter clicking continuously without lighting. This is caused by misaligned burner caps (most often after cleaning) or clogged burner ports — not a fault code situation. Confirm burner caps are seated flat and ports are clear before scheduling a service call.

Full LG Range & Oven Error Code Reference Table

All-in costs are 2026 US estimates including parts and labor. Actual costs vary by market, model, and service provider. Safety codes (F2, F13) require professional inspection regardless of cost.

DIY vs. Call a Tech: Decision Guide

Always reset first — press CLEAR/OFF, then 30-second breaker off — for every code before doing anything else. F3, F6, and F11 are frequently transient and may not return after a clean power cycle.

Safe to diagnose and repair yourself:

• F1, F4, F5 (sensor codes): Test thermistor resistance with a multimeter — should read ~1,080–1,090 ohms at room temp. Sensor replacement is a 2-screw swap with the range unplugged. Beginner-level repair.
• F8 (probe error): Check that the meat probe is fully seated. Inspect the jack for debris. Replace the probe if needed ($25–60, user-replaceable, no tools required).
• F9 on electric (bake element failure): Visual check for damage, then multimeter test. Bake element swap is a beginner DIY — unplug, 2 screws, 2 connectors. Always confirm the range is unplugged before touching the element wiring.
• F10 / F12 (door lock) — after confirming latch is mechanically clear: Moderate DIY difficulty; the door lock assembly is accessible but varies by model. Confirm model-specific disassembly steps before ordering parts.

Call a technician:

• F2 or F13 (oven runaway): Do not attempt to diagnose yourself. Turn off the breaker and call a professional — relay board inspection and potential board replacement cannot safely be done without proper diagnostic tools.
• F9 on gas (igniter replacement): Competent DIYers can replace a gas oven igniter, but any work near gas connections requires a leak test after reassembly. If you do not have leak test solution or are not comfortable testing, use a licensed technician.
• F7 (convection fan) returns after visual inspection: Motor access requires disassembly of the oven rear interior panel on most LG models — better handled by a professional on the first attempt.
• F11 (board communication) returns after two resets: Main board or wiring harness fault — requires diagnostic equipment to determine which board is the source of the communication failure before ordering a $250–450 part.

Repair vs. Replace: The 50% Rule Applied to LG Ranges

The appliance industry's standard threshold is the 50% rule: if the all-in repair cost exceeds 50% of a comparable replacement unit's price, replacement is typically the better financial decision. In 2026, comparable LG freestanding ranges run $900–$1,600 (electric) and $1,000–$1,800 (gas), with slide-in models reaching $1,400–$2,400. The 50% threshold lands at $450–$1,200 depending on the model tier.

• F1, F4, F5 (thermistor): $120–200 all-in — almost always worth repairing. Thermistors are inexpensive and the repair doesn't touch any other system.
• F9 (bake element or igniter): $130–280 all-in — worth repairing at virtually any range age. These are the most common wear items on any oven.
• F8 (meat probe): $0–60 — repair is essentially always warranted; it's a user-serviceable part.
• F10, F12 (door lock): $200–300 all-in — worth repairing on units under 10 years old. The door lock is isolated from the main electrical system so this repair does not age the range further.
• F7 (convection fan): $240–380 all-in — repair on units under 10 years; borderline on older units. A range still heating correctly but lacking convection may not warrant a $380 repair if the unit is 12+ years old.
• F2, F13 (runaway / relay board): $300–600 all-in — evaluate against unit age. If the relay board and main board both need replacement on a 12+ year old range, total repair cost may approach or exceed the 50% threshold.
• F11 (main control board): $380–580 all-in — evaluate against unit age. A 3-year-old range is clearly worth repairing; a 15-year-old range may not be.

The key variable is the range's manufacture date, not the purchase date. An appliance purchased 3 years ago may have sat in a warehouse for 1–2 years, making it effectively older. Use the LG serial number decoder guide to extract the exact manufacture date from your serial number, or look it up instantly at /product/serial-decoder. Then run the repair-vs-replace math with the correct unit age before committing to a repair.