Microwave Sparking or Noisy

What usually causes it

• Metal in the cavity. Foil, twist ties, metal trim on dishes and some travel mugs arc.
• Waveguide cover. The small panel on the cavity wall gets soaked with grease and can burn through.
• Damaged cavity paint. Chipped paint exposes bare metal that can arc.
• Rack supports. On models with a metal rack, missing supports allow arcing.
• Turntable motor and roller ring. A dirty roller ring or failing motor grinds or clicks.
• Cooling fan and vent fan. Bearings wear and squeal.
• Magnetron and transformer. A loud buzz during heating can mean high-voltage trouble.

Microwave sparking

Sparks usually come from metal inside, a damaged waveguide cover, or burned spots on the cavity paint.

Check first: Stop using it and check for foil or metal trim on dishes.

Microwave making noise

Loud humming or grinding can come from the turntable motor, the fan, or the magnetron.

Check first: Note whether the noise happens with the vent fan off.

Safe checks you can do

• Stop the microwave and check for metal.
• Clean the cavity, including the waveguide cover, with mild soap and water.
• Look for burn marks or holes in the waveguide cover and chipped paint.
• Clean the turntable roller ring and the tray support.

Parts that fail most often

• Waveguide covers burn through on microwaves that are not cleaned often.
• Turntable motors wear out.

How your home affects it

In older homes

Older homes in the Houston area often have smaller kitchens and laundry closets built for smaller appliances, older wiring, and shut-off valves that have not been turned in years. Many older kitchens recirculate air instead of venting outside, so filters do all the work.

In new construction

Newer homes in the Houston area usually come with builder-grade appliances, and many early problems are installation issues rather than failed parts. Ducted hoods and over-the-range microwaves sometimes have a damper that was never opened.

In apartments and condos

In apartments, condos and townhomes around the Houston area, space is tight and the building often has its own rules for access, parking and shut-off valves. An over-the-range microwave or recirculating hood is often the only kitchen ventilation.

In garages

Plenty of homes in the Houston area keep a second fridge, a freezer or the laundry in the garage, where summer heat regularly passes 100°F. Outdoor kitchen hoods need weather-rated parts and regular cleaning.

During storm season

Storm season around the Houston area brings power outages, surges and sometimes flooding, and appliances often show problems right after the lights come back on. Surges can take out hood and microwave control boards; mention any recent outage when you call.

When to call for repair

• Sparking continues with no metal inside.
• You see burned spots on the cavity wall.
• A loud buzz during heating.

Do not open the microwave cabinet. If it sparks or smells burnt, stop using it.

Need help? We do microwave repair across Harris, Fort Bend and Montgomery counties. Call (832) 345-9300, Monday to Friday, 9 AM to 6 PM. Every repair comes with a 1-year warranty on labor.

Common questions