Lg Microwave: not heating

Professional Repair Guide

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.

Urgency: Medium

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

Easy 5–10 minutes
  1. Confirm microwave is plugged into a working outlet.
  2. Check that correct power level/time settings are selected.
  3. Try resetting by unplugging for 60 seconds and replugging.
⚠️ Safety First: No internal access needed.

Check and clean door latch and switches

Moderate 15–30 minutes
Tools Needed: Screwdriver, multimeter (optional)
  1. Unplug the microwave.
  2. Inspect door latch for debris, clean the area.
  3. Use multimeter to test door switches for continuity.
  4. Replace faulty switches with matching replacements.
⚠️ Safety First: Ensure microwave is unplugged; door switch assembly requires some disassembly.

Professional Repairs

Replace magnetron

Estimated Cost: $100–$300

Replace high‑voltage diode or capacitor

Estimated Cost: $50–$150

Replace control board

Estimated Cost: $150–$300

When to Call a Professional

Internal component failure confirmed by testing (magnetron/diode/capacitor)
Microwave emits smoke, sparks, or burning smell
Unusual noises implying high‑voltage component failure

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?
Common causes include a faulty magnetron, door switch failure, or a defective high-voltage capacitor.
How do I fix LG Microwave not heating myself?
Check the power and settings, and inspect the door latch and switches for debris.
How much does it cost to fix not heating?
Professional repairs can range from $50 to $300 depending on the issue.
When should I call a technician for not heating?
If DIY solutions fail or if the problem involves complex components, it's best to consult a technician.

References & Sources

Community Analytical Insights

Analysis based on real user discussions from appliance repair communities

Can I Fix This Myself?

50%
DIY Success Rate Difficulty: Either

Common Issues Reported by Users

  • Faulty magnetron (6 mentions)
  • Door switch issues (3 mentions)
  • Damaged connectors (2 mentions)

User Suggested Solutions

  1. Replace the magnetron

    Success rate: 24.0%

  2. Adjust door switches

    Success rate: 6.0%

  3. Replace damaged connectors

    Success rate: 6.0%

  4. Replace inverter board

    Success rate: 12.0%
Analysis based on 13 community discussions
View Sources

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

  1. Microwave keeps breaking
  2. Microwave stops working when I make popcorn.
  3. Panasonic microwave inverter boards interchangeable?
  4. Can I replace this microwave wiring harness safely?
  5. LG Microwave stops heating after 5-10 mins
  6. LG Microwave Broken?
  7. What Brand to Replace LG Kitchen Appliances?
  8. LG LMV2015ST - over the range Microwave wont start.
  9. LG LMC2075BD Microwave Doesn't Microwave
  10. Lg microwave not heating up
  11. LG LMV1831ST microwave turns on but not heating
  12. LG LMC0975ST Inverter Microwave
  13. 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.

DIY View on Reddit →

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.

DIY View on Reddit →

suddenly stopped heating food

Replaced the damaged connector with a new one, but there may be a bigger issue with the control board.

DIY View on Reddit →

Microwave stops working when making popcorn

Microwaving water for 3 minutes at high power seems to restore functionality temporarily.

Pro needed View on Reddit →

Looking for a replacement inverter

The Panasonic A606Y4T00AP is a suitable substitute for the LG 6871W1S019A inverter board, but requires soldering a ground wire.

DIY View on Reddit →

Source: Reddit r/appliancerepair

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