When a microwave is running but not heating anything, you may hear a strange noise, often described as a low hum or buzzing sound. This sound is normal and is a result of the microwave's internal components and the way it operates. Here are a few reasons why microwaves make that noise:
Fan: Most microwaves have an internal cooling fan that helps dissipate the heat generated during operation. Even when the microwave is not heating food, the fan may continue to run to keep the components cool. This fan noise can contribute to the humming sound.
Magnetron: The magnetron is the component responsible for generating the microwaves that heat the food. It operates on a cycle, switching on and off to produce the microwaves. This cyclical operation can create a rhythmic humming or buzzing noise.
Power level: Even when not heating food, some microwaves may still produce low-power microwaves for certain functions, such as maintaining the digital clock or other settings. This can contribute to the sound you hear.
Electronics and transformers: Microwaves have various electronic components, such as transformers, that may produce vibrations or hum when the microwave is powered on.
Capacitors: Capacitors are used to store electrical energy and help in the smooth operation of the microwave. They can sometimes produce a faint humming sound.
The noise should not be overly loud or disruptive. If you notice any unusual or significantly loud sounds coming from your microwave, it might be a sign of a malfunction or an issue with the internal components. In such cases, it's best to have the microwave checked by a qualified technician to ensure safe and proper operation.