Can You Microwave Nothing? (What Happens, Is It Dangerous + More)

A microwave is a great appliance to have at home, especially if you lead a fast-paced life. Just pop your meal in the microwave, nuke your meal for a couple of minutes, and your food is ready.

However, what happens if you accidentally turn on the microwave with nothing in the microwave? I looked into it, and here is what I discovered!

Can You Microwave Nothing?

Turning on an empty microwave can damage the microwave. Since the microwaves produced are not absorbed by anything, the microwaves are instead redirected to the unit’s magnetron. Since the magnetron is producing microwaves as well as absorbing these microwaves, the magnetron can break down and you will have to replace the magnetron to get the microwave working again.

In case you are interested to learn more about the dangers of running the microwave while empty and the signs that your microwave has been damaged because of it, keep reading!

What Happens If You Microwave Nothing?

Microwaving nothing can potentially destroy your microwave unit. However, the damage is often guaranteed only when you allow the microwave unit to run empty for longer than 5 minutes.

After reaching the 5-minute mark, the microwave’s magnetron would have absorbed much of the heat it has produced, resulting in the magnetron’s malfunction.

Without the magnetron, the microwave unit will not function. As such, you will either have to purchase a new microwave unit or get the magnetron replaced.

How Long Can You Microwave Nothing?

A microwave unit can operate with nothing inside it for approximately 5 minutes. Any longer than 5 minutes, and the microwave is likely to shut down or catch on fire.

However, if you turn the microwave off on or before the 5-minute mark, the microwave should not incur any significant damage, if at all.

Can You Ruin A Microwave By Running It Without Nothing In It?

It is possible to permanently ruin a microwave unit by letting the microwave unit run empty.

Depending on the settings of your microwave and how long you let the microwave run empty, the microwave can either have reversible or irreversible damage.

Nevertheless, a simple accident like turning on the microwave unit for a couple of seconds without putting the food in the unit is unlikely to have any significant effect.

Can You Leave A Microwave On With Nothing In It?

If you are preheating the microwave unit because you are preparing to cook food in the microwave, leaving a microwave on with nothing in the microwave is okay.

However, preheating is only done with microwave convection ovens, not with traditional microwave ovens.

Since microwave convection ovens heat differently than a traditional microwave oven, microwave convection ovens are less likely to get damaged when preheated empty.

Can You Heat A Microwave With Nothing In It?

Can You Heat A Microwave With Nothing In It?

On account of how microwaves operate, there is no need to warm up a microwave unit before cooking or reheating anything in the microwave unit.

However, if you simply want to observe how well your microwave unit is operating, make sure to at least place a cup of cool water in the unit.

By putting a cup of water inside the microwave unit, the microwaves get absorbed in the water, which will prevent the microwave unit’s magnetron from getting damaged.

Why Shouldn’t You Microwave Nothing?

Microwaving nothing is a sure way to damage your microwave unit. At worst, the microwave unit can malfunction or even start a fire.

Even if your microwave unit simply shuts down, the microwave unit can be extremely hot to touch, and the microwave unit can emit an awful smell inside your home.

Do Microwaves Explode When Empty?

Contrary to popular belief, microwaves units do not explode. While the glass tray in the microwave unit might break or burst, the microwave unit itself is not prone to bursting.

Nonetheless, a microwave unit that runs with nothing in it for too long can potentially start a fire and pose risks to you and your property.

How To Tell If The Microwave Was Damaged By Running Empty For Four Minutes?

You can tell if a microwave unit was damaged by running empty for several minutes when the microwave unit does not turn on again, even after allowing the microwave unit to rest.

In case the microwave unit turns on, try microwaving a glass of cool water. If the water does not heat up, it is likely the microwave unit’s magnetron needs to be replaced.

Is It Dangerous To Run A Microwave Empty?

Running a microwave unit empty is dangerous because there is a risk of the microwave unit catching fire. Consequently, the fire can spread to your belongings and easily escalate.

Additionally, putting out the fire can leave you with burns. While there is no guarantee that a microwave unit running empty will eventually catch fire, it is best not to risk it.

Can Running An Empty Microwave Cause a Fire?

Some microwaves that run empty have a higher tendency of catching fire than others. While a rare occurrence, microwaves that run empty are always at risk of catching fire.

Generally, a fire can start because the microwave unit is forced to absorb all the microwaves produced by the magnetron. Consequently, certain parts of the microwave unit can spark.

Can An Empty Microwave Catch Fire?

Even an empty microwave unit can catch fire when overheated because the microwave unit has parts that can spark when exposed to too much heat.

Plus, the microwaves produced by a microwave unit are designed to excite water particles, and microwave units have none of those.

Take a look at our other articles to learn if you can microwave napkins, if you can microwave bacon, and if you can microwave broccoli.


Microwave units should never be turned on without any food or item inside the microwave. When you do so, the microwave unit will likely get damaged in the process.

Nonetheless, the occasional mistake of running a microwave unit empty for a few seconds should not result in any significant damage or hazard.

It is only when the microwave unit runs empty for more than five minutes that the risk of the microwave unit malfunctioning or even catching fire is amplified.

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