Does Arcing Damage A Microwave?

On any day, you will find a microwave useful. The versatile kitchen appliance offers an effortless mode of reheating, cooking, disinfecting, roasting, and more. All that is within a short time, depending on the model. But all these benefits can cease any moment your oven begins arcing.

The action is a fire hazard that can smoke your kitchen in minutes. When you set your microwave ready to cook, it flickers/sparks inside the cooking chamber. Besides a thwarted cooking process, arcing damages microwave ovens. It can cause a short circuit and damage your oven beyond repair.

This bad reaction occurs in microwaves when their metallic surface gets into contact with gold-painted utensils, silverware, and other metallic items. There are more causes of this dangerous reaction in your microwave oven. Keep reading.

Is Microwave Arcing Dangerous?

Any process that causes sparks or flashes in your microwave or any other electrical cookware is dangerous. Sparks signify fire, so you should act fast when you notice any. The first thing to do is treat the sparking as an emergency. Cut off the power supply to your gadget. Switch off and unplug before you seek to know what caused the arcing.

The above safety procedure is because microwave arcing is a dangerous reaction. The arcing, also sparking or flashing, occurs when there is an error in electrical currents. An unintended circuit occurs between two points, thus causing a fire. The process also causes the release of nitrogen oxides and trioxygen/ozone gas, which are harmful chemicals to human health.

Scientists attribute the above two chemicals as a cause of acute and chronic illnesses. Exposure can cause headaches, lung ailments, shortness of breath, and other severe symptoms.  

The good news is you can avoid arcing in your microwave. Continue reading to learn the tricks.

What Causes Arcing In A Microwave?

 As I have elaborated earlier, arcing is dangerous in your microwave. It is not one of the occurrences that brush it off and postpone attention. It can destroy your device beyond remedy or cause a fire. Also, arcing has several health effects, like headaches and chest pains.

The gases, which include ozone and other oxides that an arcing microwave releases are harmful. Any time sparking happens, that’s a cause for worry and requires your urgent attention. To sort out arcing in your microwave, you must first determine the cause.

So, here are various causes of arcing in a microwave;

  • Exploded diode
  • Operating an empty microwave
  • Dirt accumulation
  • Metallic objects in the oven
  • Damaged rack 
  • Recycled paper
  • Corroded wires
  • Bad terminals
  • Overloaded circuit
  • Defaced waveguide cover
  • Missing or wrong turntable

To help you figure out the above issues, I will go through each one of them;

  1. Exploded Diode

The diode lies in the belly of your microwave. Its purpose is to transform the AC (alternating current) power to DC (direct current). It doubles the current (voltage) to about 5000V. The high volts power the heating unit, known as a magnetron. With such a voltage, your microwave can make coffee, cook, bake, roast, bake, and reheat your food to your liking.  

An exploded Diode means that your microwave uses insufficient AC power or none at all. So your microwave will not heat. A faulty or shorted diode can also cause loud humming, visual sparks of fire, and a burning smell.  


The way to fix a faulty diode is a replacement. Mostly, this electrical organ of your microwave is not smooth to repair, and if you manage to fix it, it doesn’t last. The best decision will be to get a replacement instead of engaging in time-consuming and costly repairs. Your kitchenware repair clinic will recommend the best one.

2. Operating An Empty Microwave

Curiosity killed the Cat! Some acts might cause serious issues with your kitchenware. Running your microwave without food can cause arcing. The magnetron tends to burn all the residues in the oven. When these burns, they can spike and cause a fire.


Unless the gadget is in display mode, do not try to run it empty. That’s too dangerous to attempt. If you are testing whether your oven is working after servicing or repairs, place some food on a plate but do not run it empty. Grease and food residues on the waveguide can spark and ignite a fire.

3. Dirt Accumulation

The best way to observe hygiene in your kitchen is to clean cookware immediately after use. Dirt accumulation in your microwave oven is a significant cause of arcing. When the magnetron burns dry and greasy residues, they emit more heat, hence the sparking. 


Clean your oven immediately after cooking to prevent dirt and grease accumulation. When the dirt is still fresh, it is easy to wipe it out. Also, use the right cleaning agents and avoid scourers.

4. Metallic Objects In The Oven

Microwave ovens have a disclaimer not to use metallic objects, foil paper, and silver/gold-painted cookware. Crockery, steel wool, and metallic bowls spark when you operate the oven and can hurt your gadget.


Familiarize your household with the right way to use your microwave. Buy microwave-safe utensils for cooking in your microwave. Also, you can give your oven a detailed cleaning session to wipe out any metal fragments that might be causing the issue.

5. Damaged shelf support

Your microwave oven may have shelf support, depending on the model. The support looks like a hook and is great for holding a shelf. When the shelf unit’s paint peels off, you will get sparking in the oven.  


A worn-out shelf unit in your microwave is hazardous to use. Remove the unit and replace it to avoid arcing and fire outbursts.   

6. Recycled Paper

Another common warning when using a microwave is the use of recycled paper. To be specific, the ones with aluminum foil elements. Aluminum foil in microwaves behaves the same way as metallic objects. It spikes to fire and can cause more damage to your oven.


Substitute aluminum foils and other metals in the oven with microwave-friendly papers and dishes. You can wrap your food with cedar wraps, glass containers, silicon wraps, and beeswax food covers. 

7. Corroded Wires

Corroded wiring is an indicator of a tired or dying microwave. The rusty wires affect the power/electricity flow in the oven. It could be as severe as dead terminals or short circuits. These can cause fire flashes when the oven is operating.


I wonder why your microwave’s electrical wires are rusty! The reason is they are encapsulated in the interior away from moisture. It’s probably due to old age (obsolescence) or poor maintenance. You have to act fast, as this is a hazard in waiting. Depending on the age of your oven, you can decide to do a wiring overhaul or replace your oven.

8. Overloaded Circuit

This problem is external to your microwave. I have noticed that any time I have dozens of appliances running in the house, a mishap happens. The microwave and toaster oven will flicker. Other gadgets may fail to operate or behave differently.  


Examine your connections and establish the number of gadgets you have loaded on the system. Reduce them to two or three, then check if your microwave sparks. If not, it was an overload.

9. Defaced Waveguide Cover

The magnetron in your microwave comes with a waveguide covering to direct the heat waves to the center of the turntable/glass flatbed—this covering also the magnetron from food particles or insects.

A defaced waveguide can cause frequent flickers. Also, dirt from food particles and fats can stick to the guide. When you turn on the microwave, the magnetron burns the residues and creates sparks.


 It is obvious that when cooking food, residues and juices find their way to the waveguide. They stick and are likely to cause a spark when you operate your oven. To prevent the accumulation of dirt,

  • Keep your appliance clean.
  • Work on it after each cooking to ensure no grease, soups, or crumbs get into the waveguide.
  • Replace defaced waveguide cover to prevent arcing. 

10. Cookware Incompatibility

Not all cookware is microwave-friendly, more so metallic dishes. They could cause the sparks you see inside your oven. 


Buy recommended cookware for microwave use. Metallic, silicon, quality plastic, and glass utensils are microwave-friendly. 

11. Missing Or Wrong Turntable

Cooking your food without the glass turntable or an improperly installed one can cause sparking. The microwave oven design includes the glass plate, a crucial component. 


Do not use the oven without the glass plate. Ensure that it is the original one and that you installed it correctly.

What Happens When A Microwave Arcs?

You now have the known causes of microwave arcing. This harmful process may damage your oven or cause a fire. Whatever the case, you must try to prevent this unsafe process from happening. It begins with how you use your oven to servicing and maintenance. 

If your microwave arcs, the following is likely to happen;

  • A Burning Smell In Your Microwave And On Your Food

When arcing occurs, a burning or pungent smell will fill your microwave. It is an irritating odor that can cause coughing, headaches, and other health concerns. Also, your food’s flavor will change.

  • Fire

Sparks are signs of fire. When they occur, a fire outburst could follow. That’s already a hazard that could cause injuries or further damage to your apartment. 

  • Extreme Damage To Your Microwave 

Frequent flickers inside your microwave can damage the waveguide, diode, magnetron, and other vital components. It is better to deal with the first spark than to wait until major damages require costly replacement. 

What To Do When Arcing Happens?

As I have detailed in this guide, microwave arcing is a hazard in your kitchen. Anything that sparks can ignite a fire. It is an emergency that, if you do not follow the right steps, can cause a fire. So, you must act fast when you notice unusual happenings, like flickers inside or outside your oven.

  • Switch off and pull the oven from the power outlet. Also, switch off your house’s main supply if there is a risk of fire outbursts.
  • Establish the reasons for arcing. In this guide, I have already outlined for you 11 causes of microwave sparking. The list will help you to narrow down the cause.
  • Solve the issue depending on the cause.
  • In case of fire, call the emergency response for the quickest intervention.
  • If you cannot determine the cause of arcing in your oven, or if it happens frequently, do not use it. Contact the company. They will send you service guys to check your microwave.

How Do You Fix An Arcing Microwave?

How Do You Fix An Arcing Microwave

Fixing an arcing microwave involves several steps. The remedy depends on what is causing the sparks. I discussed up to eleven causes of microwave arcs. You will not need to apply all those.

Any time I experience microwave arcing, I prefer to start with the most obvious. That includes removing metallic objects or wiping the oven to remove steel wool dust. If none of the above solves the issue, you can then go on and apply the other fixes. 

Just in case it slipped off your mind, here’s the summary;

  1. Replace worn-out diode, waveguide, and magnetron.
  2. Clean your microwave often to prevent grease, gravy, and crumbs accumulation.
  3. In your microwave, stop using metallic objects like foil paper, cutlery, and silver/gold painted dishes.
  4.  Use microwave-friendly cookware.
  5. Install the oven’s glass flat plate always when microwaving food. The plate should be the right size so that it fits perfectly.
  6. Do not microwave foods wrapped in foil paper, e.g., milk.
  7. Establish faulty wiring for both your microwave and the power source. Repair or replace.
  8. Do not overload the electrical system when using your oven. 
  9. Ensure that you do not run an empty microwave.
  10. Call the service department if you cannot establish the cause for your microwave’s arcing.

Good Luck!

Related articles

What Causes Hole In Microwave?