Top Reasons Why Microwave Is Not Heating

Microwave ovens have revolutionized the way many people around the world prepare and eat their food.

If your microwave is no longer heating properly, it’s important to stop using it until you have targeted the source of the trouble.

From defective door switches to a faulty magnetron, a lot can go wrong with a microwave. Always start with the most obvious and work your way up to find the root cause of your microwave not heating.

Failed Magnetron

What is it: The magnetron is perhaps the most important part of a microwave and is responsible for the heat generated within the unit.

Magnetrons are oscillators that emit electrons from a hot cathode.

These electrons are emitted past resonant anode cavities, which ultimately generate the microwave energy responsible for heating your food.

Why it fails: A defective magnetron will result in your microwave not heating. There are a number of factors associated with the magnetron that could affect its performance. It’s best to start with lesser parts before replacing the magnetron outright.

In the following examples, you will see parts that can indirectly affect the performance of the magnetron. It’s always better to test them first and work your way in.

These parts are going to cost far less to replace compared to replacing a magnetron, so start small and test each one to ensure that they are functioning properly.

How to fix: You will need to check your magnetron with your multimeter to help you determine if the magnetron is working correctly.

You will first need to remove the housing around your microwave to access the magnetron.

This is a large, metal, square-shaped unit that is usually visible immediately after opening the housing.

You should see a wire connection plugged into the magnetron. After unplugging the magnetron, connect the multimeter probes to the exposed terminals.

First, make sure that your multimeter is set to its ohm setting. After connecting the probes to the terminals, your multimeter should read less than 1 ohm.

Anything greater will let you know that the magnetron is defective and needs to be replaced.

Magnetrons are not able to be fixed. Anytime that you have a defective unit, replacement is your only option unless you decide to buy a new microwave altogether.

Microwave ovens have revolutionized the way many people around the world prepare and eat their food.

If your microwave is no longer heating properly, it’s important to stop using it until you have targeted the source of the trouble.

From defective door switches to a faulty magnetron, a lot can go wrong with a microwave. Always start with the most obvious and work your way up to find the root cause of your microwave not heating.

Failed Magnetron

What is it: The magnetron is perhaps the most important part of a microwave and is responsible for the heat generated within the unit.

Magnetrons are oscillators that emit electrons from a hot cathode.

These electrons are emitted past resonant anode cavities, which ultimately generate the microwave energy responsible for heating your food.

Why it fails: A defective magnetron will result in your microwave not heating. There are a number of factors associated with the magnetron that could affect its performance. It’s best to start with lesser parts before replacing the magnetron outright.

In the following examples, you will see parts that can indirectly affect the performance of the magnetron. It’s always better to test them first and work your way in.

These parts are going to cost far less to replace compared to replacing a magnetron, so start small and test each one to ensure that they are functioning properly.

How to fix: You will need to check your magnetron with your multimeter to help you determine if the magnetron is working correctly.

You will first need to remove the housing around your microwave to access the magnetron.

This is a large, metal, square-shaped unit that is usually visible immediately after opening the housing.

You should see a wire connection plugged into the magnetron. After unplugging the magnetron, connect the multimeter probes to the exposed terminals.

First, make sure that your multimeter is set to its ohm setting. After connecting the probes to the terminals, your multimeter should read less than 1 ohm.

Anything greater will let you know that the magnetron is defective and needs to be replaced.

Magnetrons are not able to be fixed. Anytime that you have a defective unit, replacement is your only option unless you decide to buy a new microwave altogether.