Why is My Microwave Sparking?

Jul 29, 2023, 12:25pm

The rotating system of your microwave is made up of the motor, roller support, tray carrier and glass tray. Its role is important, because it allows the waves to be distributed over all the food for even cooking.

The microwave is a device that must be maintained regularly to avoid certain breakdowns. However, it can happen that it makes sparks. In this case, the following elements must be checked:

  • tank
  • mica plate
  • the door
  • the magnetron

Witnessing sparks inside your microwave oven can be quite alarming. Microwaves are generally safe appliances, but seeing sparks can raise questions about safety and functionality. It is important to understand why this is happening and what steps to take to address this issue. Here are some common reasons why your microwave might be sparking and how to deal with them.

Why is My Microwave Sparking?

Food Splatter

If food splatters onto the walls or ceiling of the microwave, it can cause sparking. This is because the microwaves generated by the appliance are reflecting off the food particles rather than being absorbed by the food you’re trying to heat, creating sparks.


Cleaning the microwave after each use will significantly reduce the risk of sparking due to food splatter. Wipe down the interior of the microwave with a soft, damp cloth. For tougher stains, use a mild detergent or a vinegar-water solution.

Metal Objects

Metal and microwaves don’t mix. If you accidentally leave a piece of aluminum foil, a metal utensil, or a container with a metallic trim in the microwave, it can cause sparks. The microwave’s electromagnetic waves bounce off the metal object, causing sparks that could potentially start a fire.


Always ensure that you do not put metal objects in the microwave. Use microwave-safe containers and utensils when heating food.

Faulty Stirrer

Your microwave has a component called a stirrer, a metal fan-like device that disperses the microwaves evenly throughout the appliance. If the stirrer is broken or faulty, the microwaves can concentrate in one area, which can cause sparking.


If you suspect that your stirrer is the issue, it’s time to call a professional. Replacing or repairing a microwave stirrer is a complex process that should be done by a trained technician.

Damaged Waveguide Cover

The waveguide cover is a component inside the microwave that allows the microwaves to pass from their source and into the main compartment to heat the food. If this cover is burnt or damaged, it can lead to sparking.


A damaged waveguide cover needs to be replaced. You can do this yourself, but you need to make sure you purchase the right part for your specific microwave model. If in doubt, seek the help of a professional.

Old or Damaged Microwave

Older microwaves, or those that have been damaged (for example, by a power surge), may spark. As microwaves age, their components can deteriorate, leading to issues such as sparking.


If your microwave is old or damaged and sparking, it may be time to replace it. Regular maintenance can extend the lifespan of your microwave, but eventually, all appliances reach the end of their operational lives.

Why is My Microwave Sparking?


Before any intervention in the microwave oven, the parasitic filter and capacitor must be discharged.

To discharge the noise filter: Using an insulated screwdriver (or pliers), tap

  • two plugs of the socket of your device (phase – neutral),
  • then a plug and a hole in the center (phase – earth)
  • and finally another plug and center hole (neutral-to-ground).

To discharge the capacitor

  • Loosen the fixing screws and remove the cover of the device.
  • Using insulated pliers, connect the two terminals of the capacitor to create a short circuit. There may be a spark, which means the capacitor is discharged.


The mica plate is one of the essential elements for the correct functioning of the device. It is located inside, on one of the walls of the microwave.

  • Remove it and check its condition. If there is moisture, clean it with a cloth and white vinegar.
  • If you notice any of these defects, you will have to replace the entire plate.


The door of your microwave oven is the element that closes the cavity. Consisting of two panels separated by a mesh, it prevents the passage of waves.

If it is in poor condition, insulation is no longer done. Make sure the door is in good condition, closes properly and is clean.

Remember, safety is paramount when dealing with electrical appliances. If your microwave is sparking, stop using it immediately to avoid the risk of fire or injury. Unplug it and diagnose the problem. If the problem is beyond a simple cleaning or the removal of metal objects, it’s best to consult a professional technician.