Lg Microwave: not turning off; overheating

Professional Repair Guide

What is this symptom?

Is your LG microwave not turning off and overheating? This issue can lead to excessive heat and potential damage. Common causes include a faulty cooling fan, thermal protection activation, or door switch malfunctions. Identifying the root cause quickly is crucial to avoid further complications.

Urgency: High

Important Tips for Lg Models

  • Specific causes for 'not turning off' in LG models are not documented in official LG support publicly; general LG repair guides reference common issues affecting operation like door switches and control board, but not continuous run specific.

Possible Causes

Faulty cooling fan or ventilation problem

How to Identify: Microwave feels very hot, fan running weakly or not at all, overheats before expected cook time; intermittent shutdown then restart after cooling. Common in community reports of overheating behavior. turn1(Chula Vista Appliance Service Center

Part: Cooling fan / ventilation system

Thermal protection / overheat sensor activation

How to Identify: Microwave stops mid‑cycle then may restart after cooling; heat protection trips due to internal overheat. (Chula Vista Appliance Service Center

Part: Thermal cutoff / thermostat

Door switch or latch malfunction causing improper control signaling

How to Identify: Microwave may run or not shut off when door opened or poorly latched; operational controls behave inconsistently. Community troubleshooting guides note door switch issues cause unpredictable behavior.

Part: Door switch assembly

Control board or timer circuit fault

How to Identify: Microwave does not shut off when timer completes; display or buttons may act erratically.

Part: Electronic control board/timer

DIY Solutions

Check ventilation clearance and ensure cooling fan operation

Moderate 10‑20 minutes
Tools Needed: screwdriver
  1. Unplug the microwave from power.
  2. Ensure the unit’s vents are not blocked and that manufacturer‑recommended clearance is present.
  3. Access rear cover to visually check if the cooling fan spins freely and is not obstructed.
  4. Clean any dust/debris from fan blades and vents.
⚠️ Safety First: Always unplug before internal inspection.

Professional Repairs

Replace cooling fan or thermal protection components

Estimated Cost: $60 - $150

Control board/timer circuit replacement

Estimated Cost: $100 - $250

When to Call a Professional

Microwave overheats and shuts off unexpectedly
Unit continues to run without stopping and internal components are hot to the touch
Fan not operating even after cleaning
Door switch appears broken

Preventive Maintenance

  • Clean vents and fan regularly: Overheating and fan obstruction
    Frequency: every 3 months

Frequently Asked Questions

Why is my LG Microwave not turning off; overheating?
Common causes include a faulty cooling fan, thermal protection activation, or door switch malfunctions.
How do I fix LG Microwave not turning off; overheating myself?
Check ventilation, ensure the cooling fan is operational, and remove any obstructions.
How much does it cost to fix not turning off; overheating?
Professional repairs typically range from $60 to $250 depending on the issue.
When should I call a technician for not turning off; overheating?
If DIY solutions do not resolve the issue or if the problem persists, contact a technician immediately.

Community Analytical Insights

Analysis based on real user discussions from appliance repair communities

Can I Fix This Myself?

60%
DIY Success Rate Difficulty: Professional

Common Issues Reported by Users

  • Faulty door switch preventing the microwave from recognizing when the door is closed or opened.
  • Malfunctioning control board that fails to send the off signal to the microwave's power supply.
  • Stuck relay on the control board causing continuous power to the microwave.

User Suggested Solutions

  1. Inspect and replace the faulty door switch. Open the microwave casing, locate the door switch, and test it with a multimeter. If it's defective, replace it with a new one.

  2. Check the control board for any signs of damage or burnt components. If damaged, replace the control board. Ensure all connections are secure.

  3. Test the relay on the control board. If it is stuck, it may need to be replaced or repaired. Disconnect power before attempting any repairs.

Analysis based on 1 community discussions
View Sources

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

  1. LG OTR microwave LMV1813ST

Community Discussions

The unit will not turn off unless unplugged and the inside is now HOT.

The issue may be related to faulty door switches.

DIY View on Reddit →

Source: Reddit r/appliancerepair

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