One of the most common questions for Appliance Repair – Will I Destroy My Microwave if it Runs Empty ?, has a simple answer. Yes, anytime the microwave is operated when empty, the owner stands a chance of damaging the device.
The heat formed in a microwave oven is due to bombarding food and liquids inside using high-frequency sound waves. The problem of operating the device without food is there is nothing inside the oven to absorb the microwave energy. Microwave energy may then feed back into the device itself, resulting in permanent damage to the magnetron, also known as the microwave antenna.
Many dishes will be labeled as microwave safe on the bottom of the container. In the United States, the label includes several horizontal waves shown parallel to each other. Some manufacturers use only the waves and others use a design with the waves over a pan. Such dishes can be used without fear.
Most stove top cookware and many of the pans used in the normal oven are not safe for microwave use. In addition, plates and bowls used to serve food may or may not be safe. It is important to make sure cookware is appropriate before using it in the microwave oven. There is a simple test which can be used to determine the safety of cookware. Simply put the cookware in the center of the oven and place a glass of water next to it. Power the microwave on high for one minute. If the water remains cool and the cookware becomes warm, it is not safe to use in the microwave.
Avoid use of metal of any type in the microwave. Metal pans and aluminum foil should not be used. Cups, bowls, plates and glasses that have a metallic rim should not be used. Even small bits of metal can cause the energy to form electrical arcs. These arcs can damage the oven.
While paper products in general are safe for use with microwaves, recycled paper is a special case and should be avoided. Whereas first time use paper is made from cellulose fiber from trees, the fiber in recycled paper may be contaminated with metal or other products that concentrate the heat from the microwaves. There have been cases where the heat is great enough to cause a fire inside the microwave.
Operating a microwave when it is empty can damage the microwave. Many people keep a cup of water in their unit when it is empty to prevent inadvertently starting it while empty. In addition, it is important that the cookware used in the oven is safe for microwaves. Look for the manufacturer's symbol or test cookware before use in the microwave oven.