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Microwave Turns On When Opening the Door? Here’s The Problem!

Microwave Turns On When Opening the Door? Here’s The Problem!

Sometimes microwaves malfunction in ways we don’t understand. For example, it turns on when opening the door, which isn’t normal — so if yours does the same thing, what could be the problem?

If your microwave turns on when opening the door it’s likely because its door is faulty. Usually, the latch on the door has a switch that controls the microwave, like turning on the lights. When it doesn’t function correctly, the microwave either continues running or stops running when the door is opened. 

Don’t toss out your microwave just because it has a faulty door! This article will discuss why your microwave is turning on when you open the door and tell you how to fix the issue. Keep reading so you can save your microwave and ensure it runs properly once again.

Your Microwave Has a Faulty Door

A faulty door is the most significant cause of microwave malfunctioning. A door may have 2 or 3 interlock switches to ensure uninterrupted running, and these switches are the main reason why your microwave’s lights turn on when the door opens (source).

The interlock switch connected with the door latch ensures that the microwave runs only when the door is closed. Metal prongs attached to the interlock switch, on the other hand, detect whether the door is closed or open. Prongs prevent the microwave from running when you click the button (in case of an open door) by sending signals to the motor.

Thus, it’s essential that you check if the door latch is properly functioning since, in most cases, a faulty latch complicates the interlock switches. A microwave with a defective door could lead to severe burn injuries for the operator. It could also damage any other electronics nearby (source).

The Interlock Switches Stay Pressed

If you think about it, then the primary issue with a microwave operating on its own is the interlock switches on the door being pressed permanently. Usually, the switches must return to their original position after being pressed. If they don’t, the microwave will keep functioning (source).

This issue, however, is continuous. It means that the microwave will still operate even after the door has been closed. If that is the issue, your microwave will turn on as soon as you switch on the power button.

Your Microwave Switches Are Heat-Sensitive

Microwaves sometimes have heat-sensitive switches. These switches function even with the slightest heat from your hands or other nearby sources in a faulty door. 

Isolate your microwave from other devices to check if heat is the issue, and use a cold object like a pen to operate the buttons. If the problem persists, it’s likely due to something else. If not, then heat is the issue.

How To Fix a Faulty Door

It’s essential to fix the faulty microwave door to ensure it runs only when the door is closed. Certain tools like a screwdriver, replacement switch, etc., are required to repair the faulty door. Apart from this, you need extra switches, with some listed below. You can purchase them from

However, before repairing the faulty door, ensure that the microwave plug is out and the capacitor isn’t running. Below are the steps I follow to repair a faulty door:

  1. Repair smartboard. Remove the upper side of the microwave cabinet and then remove the keypad. The smartboard lies behind the keypad. As soon as the keypad is removed, you can see your smartboard.
  2. Locate interlock switches. Check how many interlock switches your microwave door has and find their exact location. You can also refer to the microwave oven manual to see the number of interlock switches and their precise location.
  3. Access the front electric panel. Carefully open the fasteners such that it isn’t damaged. Then, open the electric panel.
  4. Take out the switch assembly once the electric panel is open. Carefully remove the three or four switches from the board.
  5. Find the faulty switch. When you press a switch on the microwave, it goes inside and then comes back to its place. Switches that don’t come back in place and remain pressed are deemed faulty. So, press each switch and identify the faulty switches.
  6. Replace faulty switches. Once you’ve identified the faulty switches, find their exact models, buy them, and put them in place by removing the faulty switches.
  7. Reassemble all the parts as they were after replacing the faulty switches. After checking whether everything has been put back or not, plug in the microwave and check if it runs when the door is open. If you’ve successfully repaired the faulty door, then it’ll no longer run when the door is open.

Here are some replacement options from for you to consider:

Should You Hire a Professional To Fix Your Microwave?

You may hire a professional to help you fix your microwave. Do this if you’re not confident in fixing the problem yourself this is recommended if your microwave has more serious issues. 


When a microwave keeps running even when the door is open, it’s likely due to faulty interlock switches and problems in door latches. It could be due to heat or the switches being pressed permanently.

You can repair faulty doors by replacing switches. Be careful while removing microwave parts and accessing the smartboard. Ensure no electricity enters the microwave during the repair.

You may require professional help to repair the faulty door of the microwave. Although, if you’ve ever repaired a motherboard of desktop computers, you can quickly fix the faulty door smartboard of the microwave since they look similar.

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