Why Is My Microwave Making Noise When Off? (Solved)

Written by Michael Harris
Last updated

If you’ve ever been in your kitchen and heard a strange noise coming from your microwave, you’re not going crazy.

You’re also not the only one who’s heard it – in fact, it’s a pretty common issue. So what’s causing it, and more importantly, how can you fix it?

Well, in this post, we’re going to walk you through exactly how to diagnose why your microwave is making noises when it’s off as well as some ideas on how to remedy the issue. Let’s get started.

Is It Normal For Microwave To Make Noise When Off?

Well, is it true? Absolutely yes. Microwaves are electronic devices that need power for their operation. They have the capability of heating food until it becomes warm.

During the heating process, some parts of the microwaves get overheated. Thanks to the presence of fans. They tend to rotate throughout the heating process to cool various components of the microwave this helps to prevent overheating.

However, when the thermostats are too hot, the fan will not go off even after switching off the microwave. They will keep rotating to ensure the temperature is low.

This is typically the reason behind the noise from your microwave even after switching off. Therefore, do not get stressed about your warming machine.

The only thing you need to confirm if the machine is capable of warming the food. If it does so, then the microwave is in the best working condition.

On the other hand, if it fails, then there is a problem that needs a fix. You can troubleshoot and diagnose the problem.

Did you know microwaves are the most used kitchen appliances? Well, this is the reason why they are highly susceptible to a lot of problems.

Fixing noisy microwaves is quite easy, and there is nothing to worry about. You only need to identify the source of the noise and adopt the steps in the guide to fix it.

Also, you can bring onboard a tech-savvy with kitchen appliance knowledge and experience to fix the issue. It is something that can be done in a few minutes once the source is known.

Why Is My Microwave Making A Noise?

The most used kitchen appliance is the microwave. The overworking issue is the reason why it tends to experience a lot of problems.

The humming and thumping noise from the microwave while warming the food is quite reasonable. This should not stress you at all, but if the sound persists even after switching it off, then there is a problem.

Here are some of the possible reasons why your microwave tends to produce noise while in operation and even after switching off. They include:

The issue with the Drive Motor

A microwave is fitted with a glass tray that tends to turn while warming the food due to driving motor. If you hear unusual sounds, then it could be a problem with the turntable drive motor.

The grinding noise can be disgusting and annoying, but the good news that once the appliance is unplugged from the power, the sound ceases.

Problem with the Magnetron

The magnetron is a high voltage circuit that helps to generate heat for the microwave, and in case it fails to work then expert to hear humming as well as a buzzing noise.

The only thing to do at the moment is to switch off the microwave, and for sure, the loud noise will cease.

The issue with the Drive

Coupler helps to power the glass tray in the microwave. The presence of noise could be a clear indication of the problem with it.

Fixing the issue is quite easy, but you will be required to switch off the appliance first. Call a kitchen appliance expert for assistance but unplugging helps to get rid of the noise.

The Roller Guide Issues

The roller guide rotates the turning tray in the microwave. The presence of the noise emanating from the turn trays as a result of friction could be a problem with the roller guide.

You can replace the rollers with new ones or lubricate the region to minimize any form of friction. These two options help to get rid of the noise.

Problem with High Voltage

Diode The low humming and buzzing sound in the microwave are quite normal while in operation. But if the sound becomes loud, then there is an issue with the high voltage diode.

The issue can easily be identified since the appliance will not heat the food at all. The high voltage diode works hand-in-hand with magnetron and capacitors.

Cooling Fan Problems

The cooling fans are usually located inside the cabinet of the microwaves, and they tend to help cool down an overheated magnetron.

The constant rotation of the fans while the appliance is in operation tends to produce noise, and this is considered normal.

Sometimes, you will notice that the fan noise persists for some more minutes. This is also normal since it is trying to cool the overheated thermostat.

Also, worn-out fan bearings can cause noise. Under such a circumstance, you will only need to fix the whole issue to minimize the noise.

How Do I Make My Noisy Microwave Quiet?

It is quite reasonable for microwaves to make low humming sounds when cooking food, and it is a clear sign that everything is fine.

On the other hand, louder humming sounds imply that there is a problem with your microwave that needs a quick fix.

Here are steps on how to fix a noisy microwave in your kitchen. Take time to read through slowly and make it quiet in the long run. They include:

1. Troubleshoot the Appliance

The first thing first. Try to troubleshoot the microwave and identify the source of the noise. This will make your work easier when wanting to fix the problem.

However, the process usually takes a couple of times, but it is quite easy to do so. You do not need to be an expert to identify the problem.

2. Fix the Drive Motor Issues

Drive motor plays are a vital role in turning the tray in the microwave. If it tends to produce loud noise while rotating, then it is an indication of a problem.

You will be expected to reach out to the drive motor from the bottom depending on the model of your microwave. Replace it with a new one.  This will help curb the noise.

Fixing Drive Coupler

If the grinding noise did not disappear after setting the drive motor, then you may have a look at the drive coupler.

It is the part that connects the engine and the turntable tray. The component plays the role of rotating the tray in the microwave, and it tends to get damaged due to dirt.

This is the reason behind the loud humming and grinding noise. You will be required to remove the damaged coupler and replace it with a new one.

Accessing the component usually depends on the model of your microwave though it is within the drive motor.

3. Deal with the Roller Guide

Issues Rollers are a component that supports the tray in the microwave. It also helps to spin the drive motor hence highly susceptible to physical damages.

The odd noise is an indication of the physical damage, and this will inhibit the tray from turning correctly. However, it is quite easy to replace.

4. Fix the Damaged Cooling Fans

Faulty cooling fans tend to make a couple of noise when the microwave is in operation. Locate the fans in the microwave first.

Inspect any presence of foreign objects around the blades and bearings of the fan. Remove them, and this will help to get rid of the noise. Also, if the bearings are worn out, replace them.

5. Replace the High Voltage Diode

Use a multimeter to test if the diode is in good condition. A damaged voltage diode result in uneven heating hence the reason behind the odd humming and buzzing sounds.

If the meter indicates any problem, then you will be required to replace the entire high voltage diode, and this will also minimize the loud sounds.

6. Fix Magnetron

This is a responsible circuit for heating the microwave. Any damage manifested in the channel will result in noise production.

Reaching the electronic device in the microwave can be difficult, and you need to be an expert to fix it. Faulty magnetron usually needs replacement.

Final Remarks

It is usual for microwaves to make noise while in operation though the sounds tend to be quite low. Hence hearing low humming, grinding, and buzzing sounds is normal.

Sometimes, the thermostat tends to get overheated, and the cooling fans need to rotate to lower the temperatures.

For this reason, it will make noise even after switching off. However, if the microwave makes odd noise that is loud, then it is a clear indication of a problem to one of the parts listed earlier.

The best way to handle such a situation is to call upon an expert with kitchen appliances to come and help fix the issue. The noise can be irritating and annoying.

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About The Author

Hey I'm Michael and I run this website. I'm a professional voiceover artist and in my search to create a silent studio I've become obsessed with soundproofing and things being quiet. Thanks for visiting and if you have any question get in touch.