LG Microwaves Not Heating: How to Fix It Yourself
When your LG microwave runs but does not produce heat, the most common cause is a blown thermal fuse or a burned-out heating element. Both are affordable parts you can replace yourself. The thermal fuse often blows because of restricted airflow, so check your vents and filters first.
⚠️ Safety First
- Always unplug the appliance from the wall before starting any repair work.
- Microwaves contain a high-voltage capacitor that can hold a lethal charge even when unplugged. Do not open the microwave cabinet unless you are experienced with appliance repair. The steps below focus on safe, external fixes.
Parts You May Need
Step-by-Step Repair
- 1
Unplug your LG microwave
Pull the power cord from the wall outlet. Safety first — never work on a plugged-in appliance.
- 2
Check the power supply
Make sure the outlet is working by plugging in something else (like a lamp). Check your home's circuit breaker panel — the breaker for your microwave may have tripped. Flip it off, then back on.
- 3
Inspect the heating element
The heating element is the part that actually creates heat. On most LG microwaves, you can access it by removing the back or bottom panel. Look for visible breaks, burn marks, or blistering on the element coil. A broken coil means the element needs replacing.
- 4
Test the thermal fuse
The thermal fuse is a safety device that shuts off heat if the microwave overheats. It is a small, flat piece usually near the heating element. If you have a multimeter, test it for continuity. No continuity means the fuse is blown and needs to be replaced (usually under $10).
- 5
Reassemble and test
Put the panels back on, plug the microwave back in, and run a short cycle to see if it heats. If it does, you have fixed it! If not, the control board or thermostat may be the issue — that is a good time to call a pro.
If That Didn't Work
- A faulty high-limit thermostat can prevent the heating system from working.
- On gas models, the gas valve solenoids may need replacing.
When to Call a Professional
If replacing the thermal fuse and heating element does not fix your LG microwave, the main control board may be failing. Board replacement costs $100-$250 with parts and labor. Compare that to the cost of a new unit if yours is older than 8 years.
Related Repairs
Disclaimer: This guide is for informational and educational purposes only and does not constitute professional repair advice. All repairs are performed at your own risk. RepairItFree.com is not liable for any personal injury, property damage, device damage, voided warranties, or other losses resulting from the use of this information.
If you are unsure about any step — especially anything involving electricity, gas, water, or refrigerant — stop and consult a qualified professional. Your safety is more important than saving money.
See our full Terms of Service for complete legal details.