Quite a few manufacturers have been efficiently producing a wide range of appliances that make our modern-day kitchens just that much simpler to use, including the microwave, which many of us find essential in our kitchen.
Microwaves are one of the most frequently used appliances around the world because they simply make our life easier. You just need to open the microwave door, put in the item you want to heat up, and after 1 to 2 minutes, you hear the sound of ready, edible, delicious food.
Therefore, if something is wrong with your microwave, it can be frustrating. Microwaves, like all other appliances, can go through problems every now and then, but there’s no need to worry about it.
Because in this article, we will examine all the reasons your microwave turns on when a door opens and explore the methods to solve this issue.
Why Does Your Microwave Turn On When The Door Opens?
There are several reasons why your microwave turns on when the door opens; for example, if the microwave door is faulty, an electronic glitch in the firmware, the internal circuit of the appliance is defective, or there is a problem with the heat-sensitive switches.
The problem of the microwave turning on while the door is open is very dangerous because the radiation from the microwave oven spreads to nearby things. Therefore, the reason for the problem must be determined quickly to fix the issue, so in the following troubleshooting steps, we’ve compiled all the possible reasons for the microwave door issue.
1. Low-Light Feature
Normally, the microwave turns its light on as soon as you open the door, especially in low-light situations, because the lights help the user to see inside the microwave.
However, the low-light feature doesn’t mean the fan should run, and the microwave should start heating up. If your microwave oven only turns the light bulb on when you open the door, then you have no problem, and the situation is fine.
If the microwave starts to heat and the tray starts spinning, then this indicates that the microwave has a problem. I had to clarify that at the beginning of the troubleshooting to make you avoid wasting your time if you don’t have a problem.
2. Faulty Door Switch
In modern microwaves, the door switch automatically disables the appliances as soon as it detects that the microwave door is open. Therefore, if the device starts to heat up and the tray spins while the door is open, that could mean the door switch is faulty.
The door switch in the microwave consists of 3 to 4 switches; you can find them beside the door latch under the bracket. These switches function by sending a signal to the microwave with the door’s status. If the door is open, the microwave doesn’t start up.
Meanwhile, the microwave receives a green light to start heating up if the door is closed. When one or all the switches fails, the microwave doesn’t receive the proper signal and fails to determine the door’s status. Therefore, you find that your microwave turns on when the door opens.
3. Electronic Glitch in the Firmware
Microwaves are one of the convenient appliances in our homes. Therefore, their development is essential to increase the convenience of the users. So, many modern microwaves have many automated functions, sensors, and a modern control board.
The control board analyzes the signals received from the sensors and outputs the desired action by the user. However, all these modern parts and systems are vulnerable to firmware glitches and errors.
If the microwave oven faces an electronic glitch, it might result in strange behaviors like turning on when you open the door. The result of glitches in firmware is unpredictable, which can be a frustrating experience when faced.
4. Defective Internal Circuit
As I have mentioned, the microwave has a lot of modern parts like sensors; therefore, it’s far more complicated than simple appliances like the toaster when it comes to its internal circuit.
The simple job of the microwave is to heat your food; however, the microwave does that by producing microwave radiation. The part responsible for the generation of this radiation is the magnetron.
Since microwave radiation is very harmful to electronic equipment and human health, the microwave must have several security systems that ensure that if something fails in the appliance, it doesn’t result in a radiation hazard.
These many security systems require a lot of internet circuits and electrical connections, which makes the chance of an electrical fault high. A loose or poor electrical connection can make your microwave operate when you open the door.
5. Water Reached the Motor
When you reheat some meals, sometimes it forms liquids that might reach the microwave motor. The liquids end up on the turntable or the tray of the microwave, which sits on the motor, then the liquids find their way to the motor.
The motor is the part responsible for the spinning of the rotator; the rotator is the part that rotates the tray so the microwave oven produces the radiation required for heating. So, when the liquids reach the motor, it might result in the motor malfunctioning.
A malfunctioning motor can send wrong signals to the rotator, which makes the rotator spin the turntable even when the door is opened.
6. Defective Rotator
As I mentioned, the rotator is the component responsible for spinning the tray or the turntable to heat the food; if the rotator is defective, it can make the turntable rotate even if the door is opened.
A defective rotator can result from water reaching it or if it has a blown fuse. Fuses are designed to protect electric appliances from power surges, so when your microwave experiences a power surge, it can result in a blown fuse in the rotator.
However, if the fuses in the rotator are in good condition and no water has affected the area, the rotator might be defective and needs to be replaced.
How To Fix A Microwave That Turns On When The Door Opens?
After discussing all the possible reasons why the microwave turns on when the door opens, like a faulty door switch, an electronic glitch, or a defective internal circuit, now, I will help with the solution of each cause.
1. Reset the Microwave
The best solution to any electronic glitch is to reset the electronic appliance, and most modern microwaves have a button designed for resetting the device. So, all you have to do is press the button, and the microwave will be reset, which should clear out the glitch.
If your microwave doesn’t have a reset button, then you will have to manually reset the appliance. First, press and hold the “OFF” or ” CLEAR” button for 3 to 5 seconds.
Then, you will hear a beep sound indicating that the device has been reset; the microwave should also display a message confirming that you have reset the appliance.
2. Perform a Quick Break
The quick break option can be done when the soft reset option doesn’t work; the quick break allows you to solve any issues the microwave sensors are facing, kindly follow the following steps to do it:
- Grab a cup and fill its half with water, sugar, or salt.
- Put the cup into the microwave.
- Adjust the setting to 30 seconds and low.
- Start the microwave.
- Press “CLEAR” or “STOP” after 30 seconds.
- Remove the cup from the microwave.
The microwave shouldn’t start when you open the door to remove the cup; however, if the problem persists, you will have to perform a hard reset, which is discussed in the next point.
3. Perform a Hard Reset
If the soft reset and the quick break options fail to solve the problem, you must then perform a hard reset to the microwave. The hard reset involves disconnecting the appliance from any power source for 30 minutes to 1 hour.
This duration allows any electric charge inside the microwave to be dissipated. After the allocated time has passed, connect the microwave and turn it on to check if the problem is solved; if the problem persists, then it might be a hardware problem.
4. Replace the Door Switch
If the door switch is the main cause of the microwave turning on when the door opens, then you will need to replace it. If you feel uncomfortable replacing the faulty switch, you can hire a qualified professional to replace it, especially if the microwave is still under warranty.
Replacing the door switch is straightforward and can be done through the following steps. Power off the microwave and disconnect it from the power source; that’s an essential step for your safety and to avoid electrical shocks.
Unthread the screws of the upper cabinet to access the screws of the display board or the keypad. Then, remove the screws of the keypad or the display board; you can use the user manual to locate the screws of the upper cabinet or the keypad.
Look under the door latch to find the switch assembly; if it is mounted using screws, you will need to unthread them to remove the switch. If you can’t find any screws, you can take out the switch assembly using your hands.
Pressing the interlock switches allows you to confirm that the switch assembly is faulty. If the interlock switches don’t generate any sound, then the switch assembly is defective and needs to be replaced.
Install the new interlock switch in the same position as the old one; however, keep in mind that if you use an interlock switch of a different model, it will not operate. The last step is to reinstall the keypad and the upper cabinet.
5. Check Internal Circuits
The internal circuits can be the reason your microwave behaves strangely; therefore, you will need to check them to ensure that there are no loose wires or poor connections.
If you feel uncomfortable checking the internal circuits of the microwave yourself, it’s recommended that you hire a qualified technician. A microwave is a complex appliance requiring certain knowledge of its inspection process; it’s dangerous to check the device without experience since it has a radiation generator.
6. Dry Off the Motor
Drying off the motor must be done as quickly as possible because if the water reaches the motor for an extended period, it can cause irreparable damage to the motor and any other components it reaches.
First, power off the microwave and disconnect it from the power source, then remove the microwave’s upper section to access the motor. Next, you will need to remove the control panel covering the motor.
Start drying the motor using paper towels or a hair dryer set to the warm setting, and you can also let the microwave dry for a while after to finish drying it manually. After the motor is dry from any water, you can then reassemble the parts of the microwave.
7. Repair the Rotator
If the water has reached the rotator, you will need to dry it using paper towels or a hair dryer set to the warm setting. If the rotator has a blown fuse, replace the fuse with a new one to get the rotator working again; however, if the rotator is damaged, unfortunately, you will need to replace it with a new one.
The following questions are the most common questions regarding the issue of the microwave turning on when the door opens:
Is it dangerous when the microwave turns on when the door opens?
If only the light bulb is turned on, and the turntable and fan stay turned off, then it’s not dangerous. Even if the turntable and fan are turned on, but the microwave doesn’t heat up, it is still not dangerous.
If the microwave starts to heat when you open the door, it can be dangerous because the microwave produces radiation to heat the food. The radiation can enter your body, damage your tissues, and increase the temperature of your body fluids.
The effects of the radiation don’t appear at the same time you are exposed to it; the effects appear after some time and after a certain amount of radiation. The radiation doesn’t only affect your body; it also affects nearby electronic devices like the refrigerator or your smartphone.
How do I know if the microwave emits radiation while the door is open?
By performing a simple test, you can easily know if the microwave emits radiation while the door is open. Place a cup of water inside the microwave while the door is open; after a while, check if the cup is heated. If the cup is heated, then the microwave emits radiation.