What Causes Microwave To Burn Inside | Safety and Troubleshooting

What Causes Microwave To Burn Inside

A microwave is essential in most kitchens, allowing us to heat up or cook food quickly. However, many homeowners occasionally notice burn marks or scorching inside the microwave.

This is often accompanied by sparking noises. Understanding what causes these issues can help you fix and prevent them.

Common Causes of Microwave Sparking and Burning

Here are some of the most common culprits when it comes to microwave sparking and burns inside your appliance:

Metal and Foil – Metal and foil can cause arcing and burns inside a microwave. Microwaves use electromagnetic waves to generate heat in food. Any metal inside the oven can spark, reflecting the waves. This generates a lot of focused heat that can scorch the interior. Foil and metal utensils are common microwave hazards.

Built-Up Food and Grease – Leftover food particles and grease buildup can lead to burning and sparks. Food that splatters or splashes while cooking can bake on the inside over time. As more debris accumulates, it can carbonize or ignite from the heat, leading to burn marks inside your microwave. Regular cleaning helps avoid this.

Rack and Wave Guide Damage – The metal rack and internal waveguide cover are susceptible to damage over time. If the protective coating chips or wears off, exposed metal can arc, which leads to sparks inside your oven. A damaged rack support or waveguide cover needs replacement.

Failing Magnetron – The magnetron is responsible for generating the microwaves. If it begins deteriorating, it can output uneven microwave distribution. This can lead to hotspots and arcing inside the oven. A failing magnetron tends to show other symptoms, like uneven cooking.

Incorrect Cookware – Using cookware not rated as microwave-safe can be problematic. Certain materials like metal and aluminum can cause sparking when microwaves interact with them. Make sure to use suitable cookware.

Why Does My Microwave Spark & Burn?

Let’s explore a few of the most common sources of microwave arcing and interior burning in more detail:

Metal Rack

The metal rack or turntable inside the microwave allows the microwaves to cook food evenly. However, the protective coating on the rack can get scratched or flake off over time.

This exposes bare metal that can reflect waves and cause sparks. The sparks can burn the nearby walls. Replacing the rack or covering it with microwave-safe paint is the solution.

Damaged Waveguide Cover

The waveguide cover is a panel that protects the oven’s waveguide from splatter. It ensures microwaves are spread evenly. If the cover gets damaged, bare metal can arc with the high-powered waves.

This will lead to burn marks and sparks during use. The waveguide cover must be replaced if it gets damaged or warped.

Foil and Metal Utensils

Using aluminum foil or metal utensils in the microwave is asking for trouble. The microwaves will induce a high voltage in the foil or utensils.

This will generate a spark as electricity arcs to the nearest surface. Repeated arcing can lead to scorch marks and burning inside the oven. Never put foil or metal in the microwave.

Food Residue Buildup

Leftover food particles and grease will bake onto the cavity walls over time. As more residue accumulates, it creates fuel waiting to be ignited.

During heating cycles, the food debris can carbonize, ignite, or spark, leaving burn marks. Regular cleaning with mild soap and water prevents this.

How to Fix Sparking & Burning in Microwave

If you notice repeated sparks inside your microwave along with scorch marks, here are some troubleshooting tips:

• Unplug the microwave and scrutinize the inside. Clean any grease buildup with a mild detergent and water.
• Check for damage to the waveguide cover or oven rack. Replace damaged parts. Repaint any exposed metal.
• Try cooking something on high power for 2-3 minutes. Note any locations where arcing occurs.
• If sparks persist from a particular spot, it could mean the cavity lining or magnetron is damaged and needs professional repair.
• Discontinue microwave use if sparking is frequent or there’s a burning smell. The appliance may be hazardous and need service.

Preventing Sparks & Burns in Microwave

You can prevent hazardous sparking and interior burning through proper microwave care:

• Always use suitable microwave-safe cookware labeled for use in the oven. Avoid all metal and foil.
• Keep the inside clean by wiping up food splatter after use and occasionally deep cleaning the walls and roof.
• Inspect the turntable, waveguide cover, and cavity walls. Repair any damage immediately before use.
• If the door or sealing is damaged, replace the microwave, as the safety interlocks may be faulty.
• Follow the manufacturer’s instructions. Please do not run the microwave empty or heat oversized portions that could overload it.

When to Call a Technician

Contact a qualified appliance technician if you notice:

• Frequent microwave sparking even after cleaning and replacing parts
• A loud buzzing noise from the magnetron
• Uneven cooking indicating magnetron failure
• Scorch marks in hard-to-clean areas
• Burning smell from the appliance

Prolonged arcing can damage the magnetron or other components. Getting it serviced before the problem escalates into a fire hazard is best. Technicians can also troubleshoot underlying issues that may be causing sparking.

FAQs

What causes a microwave to burn inside?

There can be several reasons why a microwave oven may burn inside. Some common reasons include a failing magnetron, damaged waveguide cover, damaged rack support, incompatible cookware, or a spark caused by a metal rack or utensil inside the microwave.

What is a magnetron?

A magnetron is a device in a microwave oven that generates the microwave energy used for cooking.

What is a diode, and how does it relate to microwave burning?

A diode is an electrical component that allows current to flow in only one direction. If a diode is faulty or damaged, it can cause the microwave to malfunction and potentially lead to burning or sparking.

Can a spark inside the microwave be dangerous?

 Yes, a spark inside the microwave can be dangerous. It can damage the microwave and, in some cases, can cause a fire hazard.

How can I prevent my microwave from burning inside?

To prevent your microwave from burning inside, ensure you are using microwave-safe cookware, avoid placing metal objects or utensils inside, and regularly clean the inside to remove any food debris or buildup.

How do I clean the inside of my microwave?

You can use a mixture of water and mild dish soap to clean the inside of your microwave. Wipe down the walls and surfaces with a soft cloth or sponge, and avoid using abrasive cleaners that could damage the microwave.

What should I do if my microwave is sparking?

If your microwave sparks, immediately stop using it and unplug it from the power source. Check for any visible damage or foreign objects inside the microwave and remove them if possible. If the sparking continues, contacting a professional technician for repair is recommended.

Can using the wrong cookware damage my microwave?

Yes, using incompatible cookware, such as metal containers or containers with metallic trim, can cause arcing and damage your microwave.

Is it safe to use a microwave with a damaged waveguide cover?

No, using a microwave with a damaged waveguide cover is unsafe. The waveguide cover protects the waveguide, which directs microwave energy into the oven cavity. If the cover is damaged, microwave energy can escape and potentially cause harm.

Can a failing magnetron cause a microwave to burn inside?

Yes, a failing magnetron can cause a microwave to burn inside. The magnetron is responsible for generating the microwave energy used for cooking, and if it malfunctions, it can lead to excessive heating or burning.

Conclusion

Occasional minor sparking in the microwave is regular. But frequent arcing accompanied by burn marks inside indicates a problem needing attention. Causes include metal, foil, food buildup, and component damage. With proper microwave use and maintenance, burns and sparks can be avoided. Discontinue use and call for service if the issue persists despite troubleshooting. Understanding what’s causing the sparking helps resolve it quickly before significant repairs are needed.