Microwave problems, lifespan and upkeep

A microwave cooks with a magnetron powered by a high-voltage circuit, which is why the useful fixes sit outside the case. The two common complaints are a microwave that runs but is not heating and one that is sparking. Repairs typically run $100–200, and anything behind the outer case can hold a dangerous charge even when unplugged, so it is for a pro.

Common problems
How long it should last

Typical lifespan: about 10 years

Signs it is near the end:

  • A budget countertop unit is over 10 years old and needs a repair.
  • The door no longer closes or latches properly.
  • It sparks with a clean, empty cavity, or the interior paint is burned through.
  • It heats weakly or unevenly even after the door and settings check out.
Basic upkeep
  • Wipe splatter off the walls and ceiling after use so it can't burn on and spark.
  • Keep the waveguide cover, the small panel on the inside wall, clean and replace it if it is scorched or cracked.
  • Never run it empty, and keep metal, foil and metallic-trimmed dishes out of it.
  • Check that the door closes firmly and the latch is clean.
  • Never open the outer cabinet: it can hold a dangerous charge even when unplugged.
Common fixes

  • Furnace won't heat?

    FurnaceFall

    The furnace runs but the house stays cold, which is usually a clogged filter, a thermostat setting, or an ignition fault.

  • Heat pump not heating?

    Heat pumpFall

    The heat pump runs but the house stays cold, which is usually thermostat settings, a clogged filter, or an iced-over outdoor unit.

  • Washer won't drain?

    Washer

    Water is left in the drum after the cycle, which is usually a clogged pump filter or a kinked drain hose.

  • Fridge not cooling?

    Fridge

    The fridge section is warm or warming. The cause depends on whether the freezer is still cold, and the first fix is often free.

  • Washer won't spin?

    Washer

    The drum fills and washes but won't spin, which is usually an unbalanced load, the lid switch, or a drain problem.

Sharpen the read

Diagnose your microwave in seconds, for free

No account, no phone number. Fixology’s AI reads your photo and tells you what’s likely wrong, how worried to be, and whether it’s a DIY fix.

Snap one of these:

  • the inside walls and the waveguide cover (the small panel on the side wall)
  • the door latch and hinges
  • any scorch marks or peeling paint inside
  • the model label (inside the door frame or on the back)

Add a note or more photos next. Nobody calls you.

Fixology helps you understand your home — it isn't a substitute for a licensed pro on serious gas, electrical, or structural work.