LG Microwave Not Heating: 7 Reasons and their Fixes

LG microwaves are very reputable. Thanks for their sleek design, multiple warming options and quick heating performance.

But like anything else, a microwave isn’t without some problems. But what can you do if your LG microwave isn’t heating?

A microwave that won’t heat is worthless. This article will explain why your LG microwave won’t heat and the potential solutions.

Why is my LG microwave not heating?

When your microwave isn’t heating, it could be due to various issues ranging from simple to complex.

Understanding what can go wrong is the first step in finding a solution.

The most common issues that lead to a microwave not heating include malfunctioning door switches, a broken magnetron, a faulty high-voltage capacitor, or a defective diode.

Each of these components plays a crucial role in the operation of your microwave, and if one fails, it can result in a lack of heat.

Always start with the basics: ensure the microwave is plugged in, the door is firmly closed, and the controls are set correctly.

Sometimes, the issue is as simple as a miscommunication between the user and appliance. If the basics are all in order, it’s time to delve deeper.

Power problems

Your microwave needs a steady supply of electricity to function properly.

If there’s an issue with the power supply, it won’t heat your food, no matter how many times you press ‘start’.

Is your outlet giving enough juice? Check to make sure your microwave is plugged into a functioning outlet.

You can test the outlet by plugging in another appliance and seeing if it works.

If the outlet is the issue, you may need to reset the breaker or replace the outlet.


If the outlet is working but your microwave still isn’t heating, try resetting it.

Unplug your microwave, wait a few moments, and then plug it back in.

This can sometimes clear any errors and restore normal function.

Turntable troubles

The turntable is an essential part of your microwave’s heating process. If it’s not spinning, your food won’t heat evenly; in some cases, it might not heat.

The turntable ensures that microwaves are distributed evenly throughout your food.

If it’s stuck or not spinning, the microwaves are concentrated in one area, which can lead to cold spots in your meal.


If your turntable isn’t budging, it’s time to roll up your sleeves. First, remove the turntable and wash it thoroughly—sometimes, food particles can hinder its rotation.

Next, inspect the rollers and the interior of the microwave for any obstructions or debris. A clean path is essential for smooth spinning.

Lastly, check the turntable motor. It may require a replacement if it’s defective, but this job is best left to professionals or those with technical know-how.

Magnetron matters

The magnetron is the component that generates the microwaves which heat your food.

If it’s faulty, your microwave will run but won’t heat.

Diagnosing a magnetron issue can be tricky, but dealing with it can be even trickier.

The magnetron uses high voltage to create microwave frequency to cook the food.

If your microwave is on, the timer is counting down, but it’s not heating; the magnetron could be the issue.

However, it’s not a part you can easily inspect or replace without proper knowledge and safety precautions.

A bad magnetron can have a few telltale signs: a burning smell, an unusual sound, or the microwave running but not heating.

If you suspect the magnetron is the problem, it’s wise to contact a professional.

Working with high-voltage components can be dangerous without the right expertise.

Door drama

A microwave door that doesn’t seal correctly can leak heat and prevent your food from warming up.

The door switches, seal, and latch all play a part in this essential function.

A simple way to check the integrity of your door seal is by inspecting it visually and tactilely for any cracks or deformities.

If you find any issues, replacing the seal is best to ensure proper functionality.

Remember, a microwave with a faulty door seal should not be operated due to safety concerns.


Check the door seal for any signs of damage or wear. If it’s compromised, it needs to be replaced to maintain the proper functioning of your microwave.

Similarly, inspect the latch for any damage or misalignment that could prevent the door from closing properly.

Control panel confusion

Sometimes, the issue isn’t with the microwave’s hardware but with its control panel.

A glitchy control panel can lead to all sorts of heating woes.

A control panel may become unresponsive or erratic due to a software glitch or a hardware malfunction.

If pressing the buttons doesn’t yield the expected response, it could mean the control board is at fault.


A soft reset can sometimes resolve control panel issues. This can be done by unplugging your microwave for a minute and then plugging it back in.

If the problem persists, the control board might need to be repaired or replaced, a task for a qualified technician.

High voltage havoc

High-voltage components like the capacitor and diode are vital for your microwave’s operation but can also be dangerous.

Handling these should be left to the professionals.

The capacitor stores and releases high-voltage electricity while the diode converts AC to DC, allowing the magnetron to heat the food.

If either of these components fails, your microwave won’t heat.

Signs of failure include a humming noise or a microwave that turns on but doesn’t heat.


If you suspect an issue with the high-voltage components, it’s time to call a pro.

These parts can retain a charge even when the microwave is unplugged and can be lethal if handled improperly.

Always prioritize safety and call a technician if you’re unsure.

Wrap up

If you’ve gone through these steps and your microwave still isn’t heating, it might be time to weigh the cost of repairs against a new purchase.

Sometimes, if the microwave is older or the repairs are extensive, buying a new one is more economical.

To keep your microwave in top shape, regularly clean it, ensure the door seals properly, and avoid slamming it.

With proper care and maintenance, you can extend the life of your microwave and avoid future heating issues.

By following these tips, you’ll likely find the culprit behind your microwave’s lack of heat and return to enjoying your hot meals in no time.

Remember to handle repairs within your skill set and consult a professional when in doubt. Safety should always be your top priority.