Thanks to modern technology, our microwaves have the ability to do so much in such a compact space. At the same time, this doesn’t mean microwaves work properly all the time. For example, the defrost function on your microwave might not be working properly. In that situation, you might be wondering what is going on. 

There are several reasons why the defrost function might not be working properly. The door switch might not be working appropriately, the microwave diode might be having an issue, or there might be something wrong with the smart board. Of course, you also need to make sure the microwave is plugged in. 

If you are concerned that there is something wrong with your microwave, we are here to help you. We have done a significant amount of research to figure out why the defrost function on the microwave might not be working as it should. 

Take a look at the results of our research below, and see if you can figure out what is wrong with your microwave. If you are ready to jump in, let’s explore how a microwave works, and why the defrost function might not be working. 

How Does the Defrost Function Work?

First, it is important to go through how the defrost function actually works on your microwave. Your microwave has multiple power settings that it uses to figure out how much juice it should deliver to your food. 

For example, if you have a standard microwave, and you are trying to heat up your food, the default setting is probably going to be 100 percent power. That is because you want your microwave to heat up your food as quickly as possible.

On the other hand, there are some situations where you do not want your microwave to use all of its capacity. If you are trying to defrost your food, you want your microwave to do exactly that. You do not want your microwave to cook your food while it is still frozen. Otherwise, you could end up eating a hockey puck. 

That is why a microwave typically uses 30 percent of its power to defrost your food. If your microwave is not defrosting your food, there are a few possible reasons why.

The power capacity that a microwave uses for defrosting
The microwave uses 30% of its power capacity for defrosting food

Check the Microwave Plug

Of course, the first thing you have to do is make sure your microwave is plugged in. This should be a relatively quick process, and it should not take you too long to diagnose this issue. Simply follow the microwave cord as it comes out of the back of the microwave.

Then, track the cord until it makes contact with the wall. The plug should be firmly rooted in an outlet. If it is not in the outlet, it needs to be plugged in. Then, see if it will start working properly.

If the microwave is still not turning on at all, this could be a sign the outlet is dead. Use another device to test the outlet to make sure it is working properly. You may also want to flip the light switch to see if the outlet is controlled by a switch.

You may also want to take a look at the circuit breaker to make sure that part of the house has not been trip. If it has, flip the circuit breaker back on and see if it starts working properly. If the circuit breaker trips again, you do not want to hold it open. Instead, you should call an electrician to figure out why your circuit is still tripping.

Check the Defrost Settings

If the microwave has power and the defrost function is still not working properly, the next thing you have to do is take a closer look at the defrost setting. Sometimes, you have the ability to customize the amount of power your microwave emits.

For example, your microwave may not be producing enough power to defrost your food. If that is the case, you may want to slightly increase the power on the defrost setting to get it to work properly. Keep in mind that you do not want to increase the defrost setting too much. Otherwise, you could end up cooking your food instead of defrosting it. 

You may also want to take a look at the food you are trying to defrost. See if there is a recommended power setting. You may want to tune your microwave to that setting to make sure you are defrosting your food without cooking it.

If the microwave is not changing power at all as you mess with the defrost setting, this could be a sign that there are other issues going on with the microwave. Fortunately, we are not done running through our possibilities just yet! 

Check the Door Switch

As you are messing with the microwave, you should also take a closer look at the door switch. The door switch is responsible for letting the microwave know that the door has closed. If the door switch is not behaving as it should, this could be a sign that the microwave thinks the door is still open when it is closed. This could be why the microwave is not working properly.

This is another issue that is not too challenging to address. The first thing you need to do is clean the door thoroughly. You might want to use a can of compressed air to remove food residue from the door switch. Or, you may want to use a cloth and some cleaning solution to wipe down the microwave itself.

If that still does not work, you may want to remove the door switch to see if it is damaged and has to be replaced. You should use your manual to figure out where the door switch is located. That way, you can figure out what type of replacement part you need if you need to replace this part of your microwave. 

Check the Microwave Diode

If the microwave is running but it is not heating your food at all, you may want to take a look at the microwave diode. There is a chance that this part of your microwave could be burnt out. Essentially, this means the motor is working properly, but the microwave is not producing any heat. 

It is the job of your diode to make sure heat only runs in one direction. In this case, the heat is running through the microwave into the food. If the diode is not working properly, this is a sign that electricity could be running in both directions. As a result, there is no net change in the temperature of your food.

If the diode has burned out, it means that there is a short in the system. Fortunately, this is not that challenging to fix. You need to take a look at the manual to see what type of diode you require. Then, you need to order that diode and replace it in your microwave.

During this situation, you will be working with an electrical component. Therefore, you have to make sure you unplug the microwave before you start working on it. Otherwise, you run the risk of electrocuting yourself. Of course, if you have any questions or concerns about this process, you need to reach out to an electrician who can help you. You always need to put safety at the top of your priority list when you are working on your microwave.

Check the Control Board

Finally, you also need to take a look at the control board. The control board is responsible for taking all the information from your microwave and distributing signals appropriately. There is a chance there might be something wrong with your control board. It might be telling your microwave that the defrost system is turned up too high when it is not.

You will need to take a closer look at your control board to see if it is working properly. Usually, this is located underneath the keypad. You should use your manual to figure out where the control board is located. Then, you may need a multimeter to test the individual components of the control board. 

A man checking the microwave's control board
The control board is located at the back of the microwave’s keypad/control buttons

Every control board is different, but you should be looking for something called a relay system. This is responsible for making sure the signals are passing through the various components of your microwave properly. If the relay system is busted, then you may need to replace it.

Some control boards are not that expensive to replace. Other control boards can be very expensive. You need to think about the cost of your microwave and compare this to the cost of the repair. That way, you can see if this is worth it or not.

These are a few of the most common reasons why your microwave might not be defrosting your food properly. Even though this is a difficult situation, there are options available. You should work with a professional to see if you need to repair your microwave or replace it entirely.

Fix a Broken Microwave

If you want your microwave to defrost your food properly, you need to make sure it uses the appropriate amount of power. In general, your microwave should use about one-third of its full power to defrost your food. If it is not using enough power, the food may not defrost. On the other hand, if the microwave uses too much power, it may cook your food instead of defrosting it. 

Fortunately, a lot of these issues you can address on your own. You should take a look at the door switch and the defrost settings to make sure the microwave is working properly. If these are not the issue, you might want to reach out to a professional who can help you take a closer look at your microwave.

You need to figure out if it is worth it to repair your microwave or if it is better to replace the microwave entirely. A professional can help you go through your pricing options to see what works best.