If a microwave oven starts by itself after being unplugged for some time, it could indicate a malfunction or an electrical issue. Here are a few possible reasons why this might occur:
Faulty control panel: The control panel or the electronic control board could be malfunctioning, causing the microwave to turn on spontaneously. This could be due to a short circuit or other internal electrical issues.
Power surge: Sometimes, power surges can affect electronic devices, including microwaves. If a power surge occurs when the microwave is plugged in, it may cause it to start unexpectedly after being unplugged and then plugged back in.
Malfunctioning door switch: Microwave ovens have safety mechanisms, such as door switches, to prevent them from operating with the door open. If a door switch becomes faulty or gets stuck, it may cause the microwave to start even when it's unplugged.
Electronic interference: In rare cases, external sources of electromagnetic radiation or radio waves could interfere with the microwave's electronic circuitry, causing it to turn on spontaneously.
If you're experiencing this issue, it's important to address it promptly to ensure safety and prevent potential damage. It is recommended to contact a professional appliance repair technician or the manufacturer's customer support to diagnose and resolve the problem. They will be able to provide specific guidance based on the make and model of your microwave oven.