LG Microwave: not heating
What is this symptom?
Is your LG microwave running but not heating food? This common issue may stem from a faulty magnetron, door switch failure, or other components. If your microwave's turntable and lights are working, yet your meals remain cold, it's time to troubleshoot and find the solution.
Important Tips for LG Models
- LG support notes that uneven or slow heating may also be due to food size or rotation issues, but if water fails to heat, internal repair is required.
Possible Causes
Faulty magnetron
How to Identify: Microwave runs normally (noise/turntable, but no heating; may hear a humming or buzzing sound; sometimes burning smell.
Part: Magnetron
Defective high‑voltage capacitor
How to Identify: No heat; internal component testing shows capacitor failure; may accompany diode or magnetron issues.
Part: High‑voltage capacitor
Door switch/latch failure
How to Identify: Microwave does not start heating because the door isn’t recognized as closed; may run other functions but cannot start high‑voltage components.
Part: Door switch assembly
Blown thermal fuse
How to Identify: Microwave stops heating after overheating condition; continuity test shows open fuse.
Part: Thermal fuse
Control board malfunction
How to Identify: Unresponsive buttons, error codes, or failure to send correct signals to components; inconsistent operation.
Part: Control board
DIY Solutions
Ensure proper power & settings
- Confirm microwave is plugged into a working outlet.
- Check that correct power level/time settings are selected.
- Try resetting by unplugging for 60 seconds and replugging.
Check and clean door latch and switches
- Unplug the microwave.
- Inspect door latch for debris, clean the area.
- Use multimeter to test door switches for continuity.
- Replace faulty switches with matching replacements.
Next step
Choose the next step for not heating
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Microwave Magnetron
Generates microwave energy for heating food and requires high-voltage service procedures.
- Typical part-only price
- $80 - $220
- DIY difficulty
- Hard
- Estimated time
- 60-120 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
Capacitor
Stores electrical energy to assist in starting or running the motor efficiently.
Door or Lid Switch
Detects whether the appliance door or lid is safely closed before operation.
Thermal Fuse
A safety device that cuts off power to the appliance if it starts to overheat.
Model-compatible Microwave parts
Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.
Professional Repairs
Replace magnetron
Replace high‑voltage diode or capacitor
Replace control board
When to Call a Professional
Preventive Maintenance
-
Clean interior and door latch regularly: Obstructions that cause latch/switch failures
Frequency: monthly -
Avoid overloading large/heavy items: Strain on components leading to overheating
Frequency: per use
Frequently Asked Questions
Why is my LG Microwave not heating?
How do I fix LG Microwave not heating myself?
How much does it cost to fix not heating?
When should I call a technician for not heating?
References & Sources
Community Analytical Insights
Guidance from available sources; statistical claims are shown only for samples of at least 10 discussions
Can I Fix This Myself?
Common Issues Reported by Users
- Faulty magnetron (6 mentions)
- Door switch issues (3 mentions)
- Damaged connectors (2 mentions)
User Suggested Solutions
-
Replace the magnetron
-
Adjust door switches
-
Replace damaged connectors
-
Replace inverter board
Analysis based on 13 community discussions
View
Sources
Data compiled from real discussions on r/appliancerepair and r/Appliances:
- Microwave keeps breaking
- Microwave stops working when I make popcorn.
- Panasonic microwave inverter boards interchangeable?
- Can I replace this microwave wiring harness safely?
- LG Microwave stops heating after 5-10 mins
- LG Microwave Broken?
- What Brand to Replace LG Kitchen Appliances?
- LG LMV2015ST - over the range Microwave wont start.
- LG LMC2075BD Microwave Doesn't Microwave
- Lg microwave not heating up
- LG LMV1831ST microwave turns on but not heating
- LG LMC0975ST Inverter Microwave
- Looking for alternative inverter board part numbers for an L...
Community Discussions
wondering if my microwave is toast
Replacing the magnetron tube is likely to solve the problem.
magnetron tests intermittent, inverter board fried
The Panasonic A606Y4T00AP is a suitable substitute for the LG 6871W1S019A inverter board, but requires soldering a ground wire.
suddenly stopped heating food
Replaced the damaged connector with a new one, but there may be a bigger issue with the control board.
Microwave stops working when making popcorn
Microwaving water for 3 minutes at high power seems to restore functionality temporarily.
Looking for a replacement inverter
The Panasonic A606Y4T00AP is a suitable substitute for the LG 6871W1S019A inverter board, but requires soldering a ground wire.
Source: Reddit r/appliancerepair
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