Five Common Microwave Problems & How To Fix Them

Spoon in microwave

Microwaves are great inventions and have simplified cooking and heating certain foods by the simple push of a button. Despite their simplicity, though, they can have faults, just like other appliances.

To know whether or not there’s an easy fix for your microwave problem or if you need to arrange for your microwave to be repaired, you first have to establish what the problem might be with it.

Here are five of the most common microwave faults:

Microwave sparking

Sparks in a microwave can be a scary sight, but generally it’s not a cause for worry, if the cause of the spark is remedied as soon as possible.

The most common reason for a sparking microwave is caused by the presence of a metal object which leads to the build-up of charged particles. The solution for this is simple. Avoid putting metal in the microwave, that includes foil and enamel coated crockery. And if you notice the sparking, remove the item to avoid excessive heat or damaging your microwave.

In rarer cases, a sparking microwave can be caused by a broken waveguide cover or faulty diode, both of which will require repair.

Read more about other causes of sparking microwaves.

Microwave is not heating food

If your microwave isn’t heating food, it’s likely that the magnetron in your appliance is broken.

Unfortunately, a burned-out magnetron can’t be repaired, it has to be replaced.

Other issues that can lead to food not being heated, includes a broken diode or a faulty door switch.

Microwave plate not spinning

The rotating glass plate in your microwave has two main purposes, which are evenly distributing heat and absorbing any excess energy the microwave puts out.

If the plate isn’t spinning correctly when operating, your food might be getting unevenly heated. This is most likely an issue with a broken motor, which can easily be replaced, and if it’s not the motor, it could be a problem with the microwave control board.

Microwave making noise

If your microwave is making a loud or unusual noise (buzzing, humming, scraping, static), there are a range of potential faults you’ll have to check for.

  • The drive motor that provides the power to rotate the plate might be faulty.
  • The magnetron might be defective, leading to an electrical humming or buzzing. The good news is that magnetron’s can be replaced.
  • The drive coupler or roller guide might be the problem, causing the rotating plate to make noise as it moves. Fix this yourself by inspecting the parts for dirt or food stuck to them.
  • The cooling fan at the back of the microwave can be damaged or obstructed, which can also cause a loud noise during operation

Microwave starts and then stops

If your microwave works when you first set it but quickly stops working after a few seconds, despite the time you’ve set it to heat for, there’s a good chance the door seal is broken. The door seal has to be triggered so that the microwave knows the door is closed in order for it to run

A broken seal can mean that the microwave still thinks it’s open, causing the operation of the microwave to stop. This is also a simple problem that can be repaired.



Saturday, December 15, 2018 at 1:00 pm

I have a built-in AEG Microwave MCC 663 which is absolutely dead although the switches indicate that there is power.The serial number is 206 OO766 and I suspect that it was installed when the flat was built in 2002. We have only been in the flat a few months and so have no idea about previous history. Postcode KT1 !AZ – next to the Rose Theatre.

We also have an AEG built-in oven which has suddenly decided not to work because the clock refuse to be set. The power lights come on and the clock lights up. Serial number -21757936 AEG thinks this is either 6 or 16 years old. I think it is probably the latter.

Hasina Patel
Saturday, March 9, 2019 at 12:23 pm


Just one to know if you are able to repair my microwave. I have a burn on the inside of the microwave door. Now I am worried that I will not be able to use it.
I can send you the picture of the burnt microwave door if you like.

I haveI a Panasonic model combi microwave.Model NN-CT5855
Sériel number 5C0713547

If it is repairable please can you tell me the costs involved.
Kindest regards

H Patel

Carolyn Hardie
Friday, August 23, 2019 at 8:22 pm

My Sharpe microwave, 800 watts, is rusting along the cavity of the oven, and along the edge of the door. The rust is a strip surrounding this area.
My oven is about 3 months old, and this has occurred with several ovens I have previously had. What can I do about this

Thursday, August 29, 2019 at 3:01 pm

This is caused by bad manufacturing quality I am afraid. To reduce it you could leave the door open to dry the interior out after use.
If you do a lot of cooking that produces a lot of steam then this could expedite the onset of rust.

Microwaves with stainless steel interiors should be immune to this but the quality of stainless that manufacturers use sometimes is bad and then rust can still develop.

If it makes you feel any better I have seen this happen to a £1000 Siemens microwave that was 4 years old.

Once there is rust on the inside of microwaves it can result in arching (sparks) and should then not be used.

Fran Banbury
Monday, January 18, 2021 at 2:48 pm

We have a Sharp Microwave combi over which is only 15 months old. The light is still working but it doesn’t appear to be heating? Might this be a setting? Or an easy fix?

Leave a Reply