Microwaves

Microwave trips the breaker

A microwave that trips its breaker, especially right at start-up, usually points to a short circuit inside the unit or it drawing more current than the circuit can handle.

Difficulty
Professional only
Time
20–30 minutes to diagnose
DIY cost
$0
Pro cost
$100–$300

Symptoms

  • Breaker trips as soon as the microwave starts or shortly after
  • May happen consistently or only occasionally
  • Other things on the same circuit may also lose power
  • Microwave may otherwise seem to work fine between trips

Likely causes

  • CommonMicrowave on a circuit shared with too many other high-draw appliancesMicrowaves draw significant current, and shared circuits can overload.
  • PossibleFailing capacitor or diode causing a shortInternal component failure can cause excess current draw.
  • PossibleWorn power cord or plugDamaged cords can short intermittently.
  • Less commonWeak or faulty breaker itselfOccasionally the breaker itself is worn and trips too easily.

What to do

  1. Check what else is on the same circuit and try running the microwave with those other things unplugged.
  2. Inspect the power cord and plug for visible damage, fraying, or discoloration, and stop using it if you see any.
  3. If it trips even alone on a circuit with nothing else running, this points more strongly to an internal fault or a genuinely undersized circuit.
  4. Note whether it trips immediately at start or partway through a longer cook, which can help a technician or electrician narrow the cause.
  5. Do not keep resetting the breaker repeatedly if it trips every single time, since this can indicate a real short.
  6. Have an electrician check the circuit capacity and a technician check the microwave itself if the circuit tests fine.

When to call a pro

Have an electrician check whether the circuit is adequately sized, and an appliance technician inspect the microwave for an internal short.

Safety

Use caution

Repeated breaker trips can indicate a short circuit; avoid repeatedly resetting and using the microwave until the cause is found.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.