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Official-source symptom guide

Microwave Sparking or Arcing: Stop, Inspect and Clean Safely

Arcing is a visible electrical discharge inside the cooking cavity. Common owner-correctable triggers include unsuitable metal, metallic trim, food debris or incorrect accessory placement, but persistent arcing or visible cavity/door damage requires service.

What can cause this symptom

  • Metal, foil, twist ties, staples or cookware with metallic trim is being used contrary to the model instructions.
  • A rack, pan or accessory is installed in a mode where the manual does not allow it.
  • Food soil or grease buildup is causing arcing in the cavity.
  • Certain foods can spark because of minerals or uneven shapes, even without a metal utensil.
  • Visible cavity coating, waveguide/inlet cover, door or internal damage may require qualified service.

Safe checks in order

  1. 1

    Stop the cycle immediately

    • Use the normal Stop/Cancel control and let the appliance stop. If safe and the manual allows, disconnect power before cleaning or inspecting the accessible cavity.
    • Do not touch a hot utensil, rack or scorched area until it has cooled.
  2. 2

    Remove obvious incompatible items

    • Remove twist ties, staples, metal utensils, non-approved racks and cookware with gold, silver or metallic trim.
    • Use foil or manufacturer-supplied metal accessories only exactly as the model manual permits.
  3. 3

    Clean the accessible cavity

    • When cool and powered off, clean food soil and grease from the cavity, door-contact area, turntable and accessible inlet/waveguide-cover area using only the mild method allowed by the manufacturer.
    • Do not scrape, puncture, sand, peel or remove the waveguide/inlet cover.
  4. 4

    Inspect visible surfaces before another use

    • Do not run another cycle if you see chipping, peeling, scorching, holes, a burned or damaged waveguide/inlet cover, or damage to the door, latch or seal.
    • If the cavity is clean, undamaged and the identified incompatible item has been removed, follow the exact model manual before resuming use.

Brand and model differences

  • Whirlpool says arcing should be stopped immediately and documents metal, foil, rack placement and soil buildup as possible causes.
  • LG warns against cookware with metallic gold, silver or similar decoration and points to cavity cleanliness and correct tray placement.
  • Samsung likewise advises removing unsuitable metal/foil and stopping use for persistent sparking or visible damage.

Actions not recommended

  • Do not continue a cycle while arcing is occurring.
  • Do not remove the outer cover, control panel or waveguide/inlet cover.
  • Do not sand, repaint, foil-patch or improvise a repair on a burned cavity.
  • Do not use metal or foil unless the exact model manual explicitly permits that configuration.

When to request service

  • Arcing continues after unsuitable items are removed and the accessible cavity is clean.
  • There is chipping, peeling, scorching, a hole or damage to the waveguide/inlet cover.
  • The door, latch or seal is damaged.
  • There is smoke, fire, burning odor, repeated breaker trips or any need for internal inspection.

Official manufacturer sources

Reviewed: September 22, 2026.