Why is My Microwave Making Popping Noise? Solved!

Microwaves are great gadgets to have in the kitchen. I honestly lost count of the number of times it bailed me out when I need to have a quick meal or snack.

In general, microwaves operate without any fuss, just like clockwork, but there are times when strange noises start appearing. It got me thinking why is my microwave making popping noise? It’s not like I have popcorn in there.

The reason why microwaves make a popping noise is likely due to food being cooked inside, an empty microwave, a damaged magnetron or a defective diode. These different conditions can contribute to the microwave making unusual noises but they can be easily fixed.

In this post, I will share more details on the causes and how you can fix these issues on your own.

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Microwave Popping Noise: General Causes

If your microwave is making popping sounds, it isn’t always because of a problem with the machine.

There are many things that can cause this phenomenon, but the most common reason is that the food inside your microwave is boiling and spitting out steam.

If your microwave is making popping noises while cooking, it could be caused by cooking spray or oils inside the microwave oven.

Cooking sprays should not be used in a microwave because they can cause a fire hazard and create a mess inside the oven. The microwave is designed to cook food, not spray cooking oils or butter.

Another possible reason for popping noises in your microwave could be that there is metal somewhere between the door and cabinet surface (such as an oven rack). If you’re having this issue and need to use an oven rack, make sure it’s lined with parchment paper or aluminum foil to prevent any scratching or damage to surfaces.

And lastly, the noise could be due to parts of the microwave being damaged or malfunctioning.

A burnt magnetron or diode has been known to cause such noises and they must be fixed swiftly to prevent further damage to the microwave and any potential danger to you.

Read on to find out how to implement fixes for these problems.

microwave making strange noises

What to do if you hear popping noises coming from your microwave?

If you hear a loud pop or explosion, turn off your microwave and the main switch immediately.

Never attempt to disassemble a microwave without first disabling the high-voltage capacitor.

Food placed too close to the roof of the microwave

When you put your food too close to the roof of the microwave oven, you may hear arcing sounds during cooking.

This happens because the metal microwave door reflects microwaves back onto your dishes and this causes sparking that makes popping noises.

To prevent this from happening, make sure that you leave at least 5 inches (12 cm) between the top of your dishes and the roof of the oven when heating them in a microwave oven.

When a metal is accidentally placed inside the oven

Metal objects being accidentally placed in the microwave can cause a loud popping sound.

The metal inside the microwave will arc and emit a high-pitched sound.

This is because of an electric field that occurs between the two metals, which causes arcing.

Arcing can damage your microwave and even start a fire if it’s not taken care of immediately!

When there is metal between the door and cabinet surface.

If your microwave is making a noise when the door is closed, it could be that there’s metal in between the door and cabinet surface.

Try pushing back on the right side and left side of the door while it is closed.

If you hear a metallic sound while opening the microwave door, then this means that there is metal in between.

Call an appliance technician to fix it.

When the magnetron is burnt

The magnetron is a device that generates the microwaves that are required to heat up your food.

In most cases when there are problems with a microwave, a damaged magnetron is often the culprit.

To test it out, make sure that you disconnect the microwave from any electrical outlet and disable the high voltage capacitor.

You will need a multimeter to conduct the test.

Touch one of the probes to the magnetron terminal and the other probe to the metal housing of the magnetron.

Depending on the model of the multimeter that you are using, you should be able to determine if the magnetron is faulty or not.

Frankly speaking, if the magnetron is damaged, you would be better off buying a new microwave than trying to replace it.

A magnetron can easily cost between $100 to $200, money which you can use to get a brand new device.

When the HV diode is damaged

The microwave high voltage diode transforms the transformer’s alternating current (AC) to direct current (DC), roughly tripling the voltage to approximately 5,000 volts.

The magnetron is powered by this high voltage to heat the food or beverage in the oven cavity.

In some cases, it could be that the diode is burnt and will need a replacement.

Similar to the magnetron, you can also use your multimeter to test it out.

If the diode is the only component causing the issue, you can replace it at a very low cost.

Other common noises made by microwaves

Popping noise when it is turned off

I find it very common to hear some kind of popping and sizzling noise on a microwave, mainly due to heating up food with high oil and water content.

If the dish is fatty, such as ham, the heat will cause the oils to sizzle, which is why it is always better to cover your food.

However, if you are still hearing such noises even when the microwave is turned off, it could be due to a problem with the thermostat failing to run the vent van.

Crackling noise and smoke observed

A cracking noise from your microwave oven, as well as sparking or smoking, indicates an electrical problem.

The heat will be released via the vent fan, but not the smoke.

The reaction of metals against microwaves is also known as microwave sparking.

This implies a significant electrical circuit problem and should prompt you to contact your electrician straight once. Overloading is indicated by a circuit breaker trip.

Grinding or screeching sounds

This sound is most likely caused by the turntable where the glass tray and your food goes on.

After prolonged usage, the motor bearings can come loose or wear down, causing an unpleasant grinding noise that sounds like the microwave is gonna explode.

You can try to attempt replacing it on your own, but the challenge will be finding the exact part you need.

What are the signs you need to change your microwave?

There are a few signs that let you know it’s time to move on to a new microwave.

If you see any of these, consider purchasing a new one.

  • Your microwave is more than 10 years old. Microwaves tend to last about 10 years before they need to be replaced (though this can vary depending on how often you use yours). If yours is older than that and still working, consider buying a new one—it will probably have better energy efficiency and safety features than the one you have now.
  • You regularly have issues with your food burning in the microwave, or it takes longer than usual for it to heat up. This can be an indication that your microwave is not powerful enough for the job anymore. You may need more power or an upgrade if this becomes a problem.
  • The door doesn’t close properly anymore because it’s warped from being opened and closed too many times over the years, or because it’s just old and worn out. This can put your food at risk for contamination when cooking and make cleaning more difficult than necessary—not only that, but if the door doesn’t close properly enough then there’s no way for the machine to operate correctly.
  • The keypad does not seem to be responsive anymore and you have a hard time setting the right settings. No matter the kind of controls you have, an unresponsive keypad will only cause you to press harder, and over time, cause more damage to the machine. Time for a new microwave, my friend.

Are microwaves supposed to crackle?

No. In normal operations, a microwave is not supposed to make crackling noises, unless it comes from the food. If you notice any unusual crackling or clicking noise that is mechanical, you should turn the machine off and contact a technician.

What is microwave arcing?

Sparks inside the microwave oven are referred to as “arcing.” Microwaves react to gold paint on plates, twist ties, and other metallic objects like aluminum foil, causing these sparks. Typically, you will solve the problem by simply removing these objects.

Why does my microwave make a weird noise?

If your microwave is making unusual noises, it’s most likely because a component has to be replaced due to frequent use. Before replacing any parts, check to see if the noise is resolved by turning the microwave off and on at the power source or by cleaning the microwave.

Can a microwave explode?

Yes, microwave ovens can explode. They can release smoke, catch fire, or explode if they have faulty wiring or are overused. If you cook with improper materials, such as metal, the oven can catch fire. Certain items, such as grapes, water, and entire eggs, can also cause oven fires.

Why is my microwave howling?

You may have a problem with the magnetron if your microwave makes an unusual or loud howling noise. The microwaves that generate the heat are provided by this component, which is part of the high voltage circuit. A loud humming or buzzing noise may be heard if the magnetron is faulty.

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Bryant Littlewood is the Chief Editor behind SoundproofingHacks. He shares all the lessons he has learned in turning his home and office into quiet sanctuaries across the blog posts here. Bryant is also a part-time audiophile, and some of the posts here will reflect that passion of his too. Connect with him on LinkedIn or read more on the about page.