Do Microwaves Shut Down When They Get Too Hot?

Automatic Shut-Off

• Some microwaves feature automatic shut-off controls that will turn off the microwave's heating element when the temperature of the microwave source gets too high. This is done to protect the microwave itself, preventing overheating that can lead to mechanical or electrical failure. If the microwave source reaches a specified temperature, it will shut down. However, features such as the timer and clock should still operate, which would not be the case if the microwave shut down due to a lack of electrical power.

Overheating Food

• Even with an automatic shut-off feature, a microwave can still overheat food. The heat from boiling water or a heated food item is contained within the microwave box, and it's not part of what the temperature sensor detects. This means that you always need to be aware of the heat settings on your microwave and handle food with care, especially if it's been cooking in the microwave for an extended period of time.

Microwave Failure

• All microwaves include fans, which cool the microwave source as it emits waves to cook food. This produces much of the sound that users hear when microwaves run. If the fans fail, the microwave may not be able to run, since it would quickly overheat if it did. In other cases, the fans may work but the sensors that detect rising levels of heat may fail, allowing the microwave to run regardless of the temperature it reaches.

Selecting a Microwave

• Automatic shut-off for overheating is one of many options you can consider when shopping for a microwave. Automatic shut-off can be found on microwaves meant for professional and household use, though it is most likely to appear on top-of-the-line models. Damage to the microwave from overheating is likely to be covered by the machine's warranty, regardless of whether it comes equipped with an automatic shut-off. Check warranty terms before buying and decide which features are most important to you.