Microwave turns on by itself

Is your microwave turning on by itself? First determine whether only the vent fan is running. On most over-the-range microwaves, the fan can turn on automatically during stovetop cooking when a thermostat detects heat, then shut off after the microwave cools. If the touchpad is working correctly and the microwave starts cooking or responds without input, the main control board is the most likely cause and may need replacement. A faulty interlock switch, including the primary or secondary door switch, can also make the microwave turn on when the door opens or cause other unexpected operation. Next, inspect the switch holder behind the control panel for damage or misalignment that prevents the door switches from engaging properly. Less commonly, circuits in the touchpad and control panel can contact each other intermittently, requiring replacement of the touchpad, control panel, or user interface. Enter your model number to find the exact replacement part for your specific microwave. Any repair that requires opening the outer cabinet must be handled carefully because the high-voltage capacitor stores a lethal charge even after the microwave is unplugged. It must be properly discharged before interior work, and this repair may require a qualified technician if you are not familiar with capacitor discharge procedures.

01 - Microwave Main Control Board

First, make sure that the touchpad is working properly. If the touchpad is working properly, the main control board is likely at fault. If the control board is defective, replace it.

Enter model number to search for the required part specific to your product

Need help finding your model number?

Shop all Microwave Main Control Board Parts

02 - Microwave cooling down during stovetop cooking

Most over-the-range microwaves have a vent fan thermostat that will turn the vent fan on automatically to keep the microwave from overheating. The fan will shut off after the microwave cools back down.

Highly Likely

03 - Microwave Interlock Switch

A microwave that turns on by itself can be caused by a malfunctioning interlock switch. You can use a multimeter to test the interlock switches to determine if they are functioning appropriately and replace if necessary.

Shop all Microwave Interlock Switch Parts

Common

04 - Microwave Switch Holder

The microwave switch holder is the component that houses the door switches behind the control panel. If the switch holder is damaged or misaligned, the switches may not be properly engaged which could cause the microwave to turn on by itself. You will need to uninstall the control panel and inspect the switch holder to confirm it is in good condition and secured properly. Replace the switch holder with a new one if necessary.

Shop all Microwave Switch Holder Parts

Common

05 - Microwave Touchpad

It’s possible that the touchpad button circuits are coming into contact with each other intermittently which could cause the microwave to turn on by itself. If this happens, the touchpad will need to be replaced.

Shop all Microwave Touchpad Parts

Less Common

06 - Microwave Touchpad and Control Panel

It’s possible that the touchpad and control panel button circuits are coming into contact with each other intermittently which could cause the microwave to turn on by itself. If this happens, the touchpad and control panel will need to be replaced.

Shop all Microwave Touchpad and Control Panel Parts

Less Common

07 - Microwave Control Board

The control board has relays that send power to several components to make the microwave work. If one or more of the relays or triacs short out, some of the components can start running when the microwave is not in use. While you can often replace just the control board, some microwave models sell control panels as an assembly with both the touchpad and control board included.

Shop all Microwave Control Board Parts

Uncommon But Possible