Why is my microwave sparking?

Author: Prof. Maria Harber IV  |  Last update: Monday, October 20, 2025

If your microwave is sparking or arcing, it is mostly likely due to the presence of metal inside the microwave, chipped interior paint, or a damaged waveguide cover. However, there may be several other reasons, such as a faulty door switch or diode, or damaged shelf supports that can also contribute to the problem.

How do I fix my microwave from sparking?

If that little round piece is sparking and you replace it (that is the turntable coupler, then it means that the paint on the microwave cavity below the coupler is wearing down. You'd need to remove the coupler and spray paint the cavity below it with ``microwave cavity paint'' to prevent it from sparking out.

Is it safe to use a microwave that sparked?

Momentary brief sparking is harmless and won't harm your microwave, but the USDA recommends turning off your microwave if you see sparks nonetheless. If it does start a fire, unless it's a very small fire, do not open your microwave door.

Why is my microwave sparking with no metal in it?

If your microwave sparks, it means that there is a short circuit in the power cord. A short circuit is when one of the wires inside the cord has come loose and touched another wire.

Is it safe to use a microwave without a waveguide cover?

There is a wave guide cover made from micarda (a mica product) that keeps food from getting into the magnetron. Yes, it is safe to use the microwave with the cover missing as long as you cover your food to keep it from spattering into the magnetron, but better to get a replacement wave guide cover.

How To Fix Microwave Sparking for $3 - Broken Microwave

When should I replace my microwave waveguide cover?

Answer: The waveguide cover protects the gap where the microwaves enter the oven cavity from where they are produced by the magnetron. Additionally, it stops moisture and food particles from getting into the "workings" of the microwave. Replace the waveguide cover if it is burnt, chipped, or cracked.

What happens if you dont use a microwave cover?

Microwaving food without a cover is generally safe for many types of food, but it may result in uneven cooking, moisture loss, and splattering. Using a microwave-safe cover or lid helps improve cooking efficiency and maintains food quality while preventing messes inside the microwave.

Why is there a random spark in my microwave?

Every microwave has a waveguide cover – it directs the microwaves from the magnetron and into the cooking chamber. If the cover is damaged it can lead to concentrated spots of energy that can cause sparks. If any part of your microwave is damaged, it's recommended that you purchase a new one or get professional help.

How to clean a microwave waveguide cover?

Keep the waveguide cover clean to make sure of good microwave performance. Carefully wipe the surface of the cover with a soft damp cloth to remove any food spatters immediately after they occur. Built-up spatters may overheat and cause smoke or possibly catch fire. Do not remove the waveguide cover.

Is it safe to use a microwave after sparking a whirlpool?

Prolonged arcing can damage the oven and/or the utensil. If caught at once, arcing should not damage the oven. Remove the offending utensil or food from the oven and substitute a microwave-safe utensil or cook the food by other methods.

What is the life expectancy of a microwave?

With normal usage for an average family and good maintenance, a microwave often lasts for 7 to 8 years. If the microwave is used less frequently by a single person or a couple and is well-maintained, the lifespan can increase to up to 10 years.

Why does my microwave spark when I make popcorn?

The microwave produces a specified amount of power, no matter what you place in the oven. If all the microwaves are not used, they will ionize the air in the corners of the oven, producing arcing and sparks. Additionally, no metal should be used in the oven compartment, as this too, will cause sparks(arcing).

What does a faulty magnetron sound like?

A screaming or screeching sound that's hard to ignore is usually caused by a defective or worn-out magnetron.

Can you still use a microwave after it catches on fire?

Is it safe to use a burnt microwave after cleaning? In most cases, yes. Make sure the cord and plug are still in good condition. Give the microwave a trial run after cleaning.

Why is my microwave sparking and tripping the breaker?

Reasons Why Your Microwave Is Tripping Your Breaker

In order for this type of reaction to occur, there must be one of two issues at hand: Too many items are plugged into the same circuit that the microwave oven is on, causing an overload. The microwave oven is defective and drawing an excessive amount of electricity.

What happens if you run a microwave with no food inside?

Running a microwave while it is empty may cause damage to the unit. When food is in the oven, it absorbs a large fraction of the output from the microwave transmitter. When the oven is empty none, or almost none of the microwaves are absorbed.

Why is my microwave suddenly sparking?

One of the most common faults for a microwave sparking is a brittle or damaged waveguide cover. This cover is a metallic sheet fitted on the inside, which guides the waves from the magnetron to cook your food.

How to tell if a waveguide is damaged?

If your microwave oven is sparking or 'arcing' during cooking it may be that the waveguide cover is damaged. Usually the cover is made of a material called mica.

Can I use a microwave without a waveguide cover?

No, it is not safe. Without the waveguide cover, the microwaves will not be distributed evenly, which will lead to the food being cooked unevenly or even burned. Additionally, food may splatter inside of the microwave guide cavity leading to permanent unit damage.

Can a dirty microwave cause sparks?

If it gets dirty or damaged it can cause sparking and result in problems heating food. There's no need for a full replacement appliance.

Can you replace a microwave waveguide cover?

Simply slide in the new waveguide cover and replace the holding screw if fitted. You can now also place the turntable and roller ring back in your microwave. Congratulations - you have now replaced the waveguide cover on your microwave. You can now get back on with life with one less worry on your mind!

How to clean a waveguide cover?

A brush intended for cleaning electronic portable devices is typically the best option, as it is softer and non-abrasive, which is beneficial for the waveguide. Following the brushing process, wiping with a microfiber cloth can pick up any leftover dust.

What can I use if I don't have a microwave cover?

Most paper towels are microwave-safe. In fact, you can use a paper towel to cover some foods so they don't spit during cooking or reheating. If you do use a paper towel while microwaving, it's best to use shorter intervals so you can check both the food and the paper more frequently.

Should you leave the microwave door open after use?

It is normal for condensation to form on the inside of the microwave, especially when you are cooking food with a high water content. This includes condensation that forms between the glass panes. The condensation will dissipate in time. You can also leave the door open to help it dissipate faster.

Where should you not put a microwave?

Settings
  1. Never Place a Microwave Too Close to the Window. Any experienced kitchen designer can tell you that placing a microwave oven at a window's frame is a bad idea. ...
  2. Keep a Microwave Out of a Corner Cabinet. ...
  3. Don't Put a Microwave Next to a Refrigerator. ...
  4. A Microwave Next to a Sink Is Asking for Trouble.

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