Microwave oven maintenance: safe use, cleaning and heating problems

The microwave is probably the most-used appliance in many kitchens, and also one of the most taken for granted. A few safe-use habits and a regular interior clean go a long way towards keeping it heating evenly and lasting well.

Understanding your microwave oven

A microwave oven heats food by producing microwaves inside a metal cavity. These make water molecules in food vibrate and warm up. A turntable or rotating antenna helps spread the heat. Convection microwaves add a heating element and fan so they can also bake and grill.

The door, its seal and its safety switches are what keep the microwaves inside the cavity, which is why a damaged door should always be checked before the oven is used again.

Common uses and benefits

• Reheating and defrosting quickly
• Steaming vegetables and cooking simple dishes
• Convection models: baking and grilling as well
• Saves energy compared with heating a large oven for small portions

Features and things to consider

• Use microwave-safe containers. Avoid metal, foil and containers with metallic trim in microwave mode.
• Do not run the microwave empty; there is nothing to absorb the energy.
• Leave space around the vents as shown in the manual.
• Cover food loosely to reduce splatter, and stir or rest food so heat spreads evenly.

Common microwave oven problems

Runs but does not heat

A component in the heating circuit may have failed; this needs a technician, not a home fix.

Turntable not rotating

The plate or roller ring may be misaligned, or the drive motor may need attention.

Sparks inside

Often metal in the cavity or food residue on the inside walls or cover plate.

Door not closing firmly

A latch or hinge issue; stop using the microwave until it is checked.

Cleaning and care tips

• Unplug before cleaning.
• Steam clean: heat a microwave-safe bowl of water with a little lemon juice or vinegar for a few minutes, let it stand with the door closed, then wipe the softened residue away.
• Wash the turntable and roller ring in warm soapy water and dry them.
• Wipe the door seal and the inside of the door gently so the door closes cleanly.
• Do not remove the cover plate inside the cavity or open the outer casing.

When to call a professional

• The microwave runs but food stays cold
• There is sparking even with no metal inside
• The door, hinges or seal are damaged
• You notice a burning smell, unusual humming or the unit trips the power