Microwave ovens are loved for so many different reasons; speedy cooking times, compactness, reliability, and pocket-friendliness, among others. 

But, all these advantages aside, have you ever noticed how loud your microwave tends to be when in use? 

This article lets you in on the core reasons behind the different noises produced by microwave ovens and why they are almost always inevitable.

why are microwaves so loud

Why are Microwaves so Loud?

Microwaves are designed to ”make noise” when in use. If you decide to do something else while the food cooks, the noise will remind you that something’s cooking.

However, the noise should not be anything louder than an insignificant humming sound.

When the humming turns into something out of the ordinary or loud enough not to disregard, it is a highly indicative sign that your appliance might be headed towards some kind of serious breakdown. 

Microwaves can and are usually loud due to different reasons. But more often, when a microwave manifests a loud sound, most people tend to blame the magnetron. 

While it might be true that the magnetron is the cause of loud noises, other components like the cooling fan, the capacitor, or the transformer may be the culprits.  

A faulty cooling fan can create loud buzzing and rattling sounds.

The microwave’s cooling fan acts as a guard that watches over the magnetron as it produces the microwaves. It ensures that the magnetron does not overheat by continuously blowing over it.

And, just like any other fan, when the microwave’s cooling fan gets caught up in dirt and clogs, you are likely to hear your microwave oven producing a buzzing sound.

Additionally, anything moveable is prone to deterioration. The microwave’s cooling fan can easily dislodge and become loose with time. When this happens, a rattling sound from the rear of your microwave will be heard. The fan tends to hit other parts as it moves.

Apart from the rattling and buzzing sounds, there’s also the peculiar hum and buzz usually caused by the capacitor, the transformer, or the diode. These three components are responsible for stepping up the energy from the wall that powers the microwave.

If the noise is more of whirring, clicking, or grinding, that’s a clear indication that your microwave’s stirrer engine is in danger of breaking down, or the turntable is wearing out, or even worse, the magnetron is failing.

Read more about weird microwave sounds here

How does a microwave oven work?

For your food to heat up in seconds, the transformer converts the regular electricity from a wall socket to power the magnetron, a device that generates high-frequency electromagnetic waves known as microwaves.

The converted electrical energy then heats the filament at the center of the magnetron, creating a surge of electrons. The boiled-off electrons are subsequently transmitted into the food chamber through an antenna.

Inside of a microwave

Inside the chamber, the microwaves are bounced back and forth, eventually penetrating the food that usually sits on a spinning glass turntable, rotating slowly to ensure even cooking.

The microwaves inside the food then activate the water molecules, making them vibrate rapidly, heating the food in the process.

The microwave oven door is tightly sealed with a metal mesh with tiny holes to keep the microwaves from escaping.

How loud should a microwave be?

Whether you stand next to your microwave when it is working, or you are doing something else in the other room, a microwave should be loud enough to remind you that there’s food in there.  

A healthy and perfectly functioning microwave should be a slight hum loud when in use. Anything louder suggests a problem with either one or several parts, or that the food is being cooked.

white microwave

How does a faulty microwave magnetron sound?

In any given microwave, the magnetron produces high-frequency electromagnetic waves that heat your food.

A perfectly working magnetron should produce a smooth and light humming sound. It’s what you usually hear when your microwave is running. If the sound gets any louder or strange, that hints at a faulty magnetron.

Depending on the issue at hand, a faulty magnetron can sound like a lot of things. A high-pitched screaming or screeching sound indicates a worn-out magnetron. A bad magnetron may also hum and buzz louder than usual.

How can I make my microwave quieter?

We all love our microwaves until they become extremely loud enough to wake the entire neighborhood when turned on at night. It can be frustrating.

Luckily enough, several DIY hacks can help you get rid of the noise entirely.

Before shifting your mind to repairs and replacements, you can try out the built-in settings that usually come with all electrical appliances. You can start by switching your microwave to silent mode.

microwave buttons

If that doesn’t solve the problem, try refreshing the sensor and hard resetting your appliance.

However, switching off your microwave and thoroughly cleaning it has proved to quiet the noise. If it doesn’t work in your case, try to find out which part is at fault and repair or replace it.

Finally, you can always get a new microwave if nothing else seems to work.


  • It’s only standard for a microwave to make a humming sound as it heats the food. The abnormal part comes in when the sound becomes hard to ignore due to a faulty magnetron or cooling fan.
  • The magnetron generates microwaves (a form of energy) by channeling electrical energy from a power source on the wall to a heated filament. That creates a flow of electrons which then blasts the microwaves into the food compartment through an antenna.
  • A bad magnetron may hum louder than usual or produce a high-pitched scream.
  • To make your microwave quieter, you either switch to the silent mode, switch the appliance off and give it a thorough clean-up, identify the faulty components and repair or replace them, or buy yourself a brand new microwave.