Microwave Maintenance Tips
Clean the inside of your microwave frequently. Food particles and splatters absorb some of the microwave energy while the unit is operating and may cause burns and other damage to the microwave. You can clean the interior with a microwave oven cleaner or an all-purpose cleaner.
Never operate a microwave oven without food or liquid inside it. Microwave ovens heat the food or liquid in the oven with super high frequency microwave sound energy. If there is no food or liquid in the oven to absorb the microwave energy, the energy can feed back to the microwave itself, which can permanently damage the magnetron and other internal components.
Your microwave oven door keeps the microwave energy inside where it belongs. If the door is in any way damaged or if the door seal does not seem to fit correctly or be in good repair, have the microwave checked by a qualified appliance repair technician.