Microwave Light Won’t Turn Off? (here’s why & what to do)

If your microwave light stays on all the time, it might not seem like that much of a problem. However, it is wasting electricity plus it’s not the way the microwave was designed to work.

Ordinarily, the light is on whilst the microwave is in use but turns off as soon as the cooking time has been completed. The light is on when cooking to allow you to keep a watch on the progress of the food as it cooks.

If the light on your microwave doesn’t go out even after the timer runs out and the food is cooked, you have a problem. But don’t worry, because in this article I explain all of the reasons why the light might stay on and offer the best ways to fix it.

Why Won’t The Microwave Light Turn Off?

There are several reasons why the light on the microwave won’t turn off which include;

Probable Cause	Solution
Sticky Button	Clean the control panel
Door Latch Fault	Inspect, clean or replace the door latch as necessary
Door Interlock Issues	Test the interlock switch for continuity and replace if necessary
Bulb Burnt Out	Check and replace the bulb
Faulty Touchpad	Check and replace the touchpad if necessary
Control Panel Damaged	Inspect and repair/replace the control panel if necessary
Faulty Wiring	Contact a technician
Electrical Or Software Issue	Contact a technician
Defective Control Board	Replace the control board if it proves to be defective

Let’s take a closer look at each of these issues;

Sticky Button 

This is one of the most often reported causes of a microwave light that won’t go off. If one of the buttons on the control panel becomes stuck it could be sending a signal to the control board to keep the light on continuously.

In many cases all you need to do is clean the control panel and remove any grease, dirt or debris to free the button and prevent it from sticking.

To do this all you need is warm soapy water and a soft cloth. Carefully wipe the surface and remove any food residue, dirt, grime or other debris. When trying to clean the more difficult to reach areas like between the buttons, try using a cotton bud or even a toothpick.

Be sure to only use a mild detergent like washing up liquid and not any harsh chemical cleaners that could potentially damage the keypad.

Door Latch Fault

If there is a fault with the door latch, it could cause the light to remain on even when the door is closed and there’s no cooking going on. What can happen is the door doesn’t close correctly because the latch doesn’t engage properly.

This leads to the control board thinking the door is open and so, keeps the light on. You should clean the latch and remove any dirt, food residue or other debris. 

Take care that there are no paper towels or other small items that could prevent the door from fully closing. Then inspect the latch for any signs of damage, or if the latch is bent or broken it will need to be replaced.

Door Interlock Issues

There’s a safety feature on microwaves that stops the appliance from operating if the door is open. This safety feature consists of a number of door interlock switches. If one of these interlock switches develops a fault, the microwave might not turn the light out once the door has been closed.

You will need to test the interlock switches for continuity and replace any that prove to be defective. However, this is often a step too far for most DIYers which is why I recommend contacting a technician to do this for you.

Bulb Burnt Out

This might sound weird but in some cases, a burnt out bulb could be stuck in the on position. Ensure the microwave is disconnected from the power supply.

You should then inspect the bulb for any signs of scorching or damage.

Then replace the bulb with the correct replacement to solve this particular problem. You can find out which bulb is the correct one for your appliance by consulting the user manual or by going to the manufacturer’s website.

Be sure that you get the correct replacement as there are different types of bulbs and similar looking bulbs with different wattages.

Faulty Touchpad 

All of your commands are entered through the touchpad. Over time the membrane can wear causing difficulties with the touchpad registering your actions.

This can lead to it not sending the message to turn the light off. The first thing to do is to clean the touchpad using a damp, soft cloth and warm soapy water.. 

If that doesn’t do the trick, you will probably need to replace the touchpad. If this is a step too far, I recommend contacting a technician to do it for you.

Control Panel Damaged

Just like the touchpad, if the control panel becomes damaged, it can cause various issues including the failure to get the light turned off.

You could try cleaning the control panel but it will almost certainly need to be professionally repaired or replaced.

Faulty Wiring

The reason the light is stuck on could be due to a wiring fault or an issue somewhere in the circuits of the microwave. There could be loose connections, burnt out wires or other problems with the circuitry.

As there are so many wires and electrical circuits in a microwave, I recommend contacting a technician to investigate and repair this problem.

Electrical Or Software Issue

In some cases there could be an electronic malfunction or software issue that prevents the light from turning off. In some cases it’s possible to solve this issue by performing a reset on the microwave.

How To Reset The Microwave

To perform a reset all you need to do is disconnect the power supply by removing the plug from the wall socket. Leave it unplugged for at least 10 to 15 minutes to allow any residual power to discharge.

After the power has discharged and the time has passed, plug the microwave back in and it should have returned to factory settings. This could have cleared the problem and the light should function as normal again.

If the reset hasn’t solved the issue, you have most likely got a problem within the circuitry or software and it will need further investigation. Unfortunately these types of issues are not easily solved and are best left to a technician to investigate and repair.

Defective Control Board

The control board sends signals to every part of the microwave. It tells each part when to operate including the light. If the control board becomes defective, it could send an incorrect message which could mean the light stays on.

Problems can arise due to power surges, wear and tear and old age. If the control board proves to be defective, it will need to be replaced. This is another job best left to a technician.

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