Lg Oven: not heating, inconsistent temperature

Professional Repair Guide

What is this symptom?

Experiencing issues with your LG oven not heating or maintaining temperature? This could result in uneven cooking, long preheat times, and fluctuating heat levels. Discover the common causes and solutions for your LG oven's heating problems.

Urgency: Medium

Important Tips for Lg Models

LG provides official troubleshooting steps for ovens that are not heating or cooking properly, including performance checks and guidance before requesting service. LG also notes the unit is properly calibrated from the factory, implying calibration should be used primarily when verified temperature offset exists rather than random swings.

Possible Causes

Failed or weakened bake heating element (electric models) causing poor or no heat and wide temperature swings

How to Identify: Oven may broil but not bake properly; visible blistering/breaks on element; element does not glow red during bake (in models where visible; continuity test fails.

Part: Bake element

Faulty oven temperature sensor (RTD/thermistor) causing incorrect temperature readings and unstable cycling

How to Identify: Oven temperature consistently off from setpoint when verified with a thermometer; temperature overshoots/undershoots; may show error codes on some models; sensor test may be out of spec.

Part: Oven temperature sensor / RTD sensor probe

Igniter failing to draw enough current (gas models) leading to delayed ignition, low heat, or no heat

How to Identify: Gas oven takes a long time to ignite, may ignite intermittently, or does not ignite at all while control indicates heating; weak/dull glow from igniter; inconsistent heating during bake.

Part: Bake igniter (hot surface igniter)

Electronic control board / control module failure causing improper power delivery to element/igniter or incorrect cycling

How to Identify: Element/igniter tests good but oven still does not heat or cycles erratically; intermittent heating; may accompany display/control anomalies.

Part: Main control board (PCB) / control module

Door gasket leakage or door not sealing properly causing heat loss and temperature instability

How to Identify: Heat escaping around door edges; visible gasket damage, flattening, or gaps; oven struggles to maintain temperature and runs longer.

Part: Oven door gasket / door hinges/closure alignment

Oven temperature calibration offset needed (unit heats consistently but actual temperature differs from display/setpoint)

How to Identify: Oven repeats the same offset when verified with a thermometer, but otherwise cycles normally.

Part: Temperature calibration setting (software offset)

DIY Solutions

Verify actual oven temperature and run LG temperature calibration (if consistently off)

Easy 20-40 minutes

Tools Needed: Oven-safe thermometer

Place an oven-safe thermometer in the center of the oven cavity (on the middle rack).
Preheat to 350Â°F and allow the oven to cycle for at least 20 minutes after it claims it is preheated.
Record thermometer readings over several minutes to see the average temperature and how much it deviates from the setpoint.
If the oven is consistently high/low by a similar amount, use the LG oven temperature adjustment (calibration) procedure in the owner's manual or LG support guidance to apply an offset.

⚠️ Safety First: Avoid touching hot racks and thermometer; use heat-resistant gloves.

Inspect bake element for visible damage (electric models) and test for continuity

Moderate 30-60 minutes

Tools Needed: Screwdriver, Multimeter, Work gloves

Turn off power at the breaker (do not rely on the control panel being off).
Visually inspect the bake element for blisters, cracks, or burn marks.
Remove the bake element mounting screws and gently pull the element forward to access wiring terminals (do not pull hard).
Disconnect the element leads and test the element for continuity with a multimeter; replace if open/no continuity.

⚠️ Safety First: Shut off power at breaker before opening panels or disconnecting wires.

Check oven door seal and closure alignment

Easy 10-20 minutes

Tools Needed: Flashlight

Inspect the door gasket for tears, flattening, missing sections, or debris buildup.
Clean the gasket and the sealing surface gently to remove baked-on residue.
Close the door and check for obvious gaps or looseness; confirm hinges are not bent and the door closes evenly.

⚠️ Safety First: Do not use harsh chemicals that can degrade the gasket material.

Professional Repairs

Replace oven temperature sensor (RTD/thermistor) and verify calibration

Estimated Cost: $120 - $300

Replace bake igniter (gas models) and verify proper ignition current

Estimated Cost: $180 - $400

Replace bake element (electric models) and inspect wiring/connectors

Estimated Cost: $150 - $350

Diagnose/replace electronic control board (PCB) or control module

Estimated Cost: $250 - $600

When to Call a Professional

If the oven is gas and you smell gas, hear gas flowing without ignition, or ignition is repeatedly delayed (turn off gas supply and ventilate).

If the breaker trips, wiring looks burned, or you see arcing/sparking.

If temperature remains unstable after verifying with a thermometer and performing calibration, suggesting sensor/control board issues.

If continuity/diagnostic tests confirm a failed component but replacement requires accessing live wiring or gas components you are not comfortable servicing.

Preventive Maintenance

Use an oven thermometer periodically to verify temperature accuracy and detect drift early.: Long-term inaccurate baking temperatures and undetected calibration drift
Frequency: Every 6-12 months
Keep door gasket and sealing surfaces clean and inspect for wear or tears.: Heat loss and temperature instability during baking/roasting
Frequency: Monthly
Avoid heavy foil covering racks/vents unless the manual allows it; maintain proper airflow for even heat circulation.: Uneven heating and temperature swings caused by restricted airflow
Frequency: Always

Frequently Asked Questions

Why is my LG Oven not heating, inconsistent temperature?

Common causes include a failed bake element, faulty temperature sensor, or igniter issues.

How do I fix LG Oven not heating, inconsistent temperature myself?

Check the temperature calibration, inspect the bake element, and ensure the door seal is tight.

How much does it cost to fix not heating, inconsistent temperature?

Professional repairs typically cost between $120 and $600 depending on the issue.

When should I call a technician for not heating, inconsistent temperature?

If DIY solutions fail or you suspect a control board issue, it's best to consult a professional.

References & Sources

Community Analytical Insights

Analysis based on real user discussions from appliance repair communities

Can I Fix This Myself?

65%

DIY Success Rate Difficulty: Either

Common Issues Reported by Users

Faulty temperature sensor
Defective heating element
Malfunctioning control board

User Suggested Solutions

Test and replace the temperature sensor. First, unplug the oven. Locate the temperature sensor inside the oven cavity, usually at the back. Use a multimeter to test for continuity. If faulty, replace it with a new one and reconnect.
Inspect and replace the heating element. Unplug the oven and access the heating element, usually located at the bottom of the oven. Check for visible damage or breaks. If defective, replace it with a compatible part.
Diagnose and replace the control board. Unplug the oven and remove the back panel to access the control board. Look for burnt components or loose connections. If damaged, replace the control board with a new one.

Analysis based on 1 community discussions
View Sources

Data compiled from real discussions on r/appliancerepair and r/Appliances:

Which dual fuel range should I buy

Community Discussions

top oven turns on broiler when set to bake, bottom oven inconsistent temperature, convection bake and roast not working

Recommended to buy a Wolf range instead of LG or NXR due to reliability concerns.