Microwaves

Outside of the microwave feels hot to the touch

Some warmth on the outer case during and after use is normal, but a case that gets very hot or hot in an unusual spot can point to a ventilation or internal issue.

Difficulty
Easy
Time
15–20 minutes
DIY cost
$0
Pro cost
$100–$200

Symptoms

  • Case feels noticeably warm or hot after or during use
  • Vents may feel like they're blowing warm air, which is normal
  • Hot spot may be limited to one specific area of the case
  • Heat lingers much longer than usual after use

Likely causes

  • CommonNormal heat dissipation through ventsMicrowaves vent some heat from the magnetron and transformer during operation, which is expected.
  • PossibleBlocked or dusty vents restricting normal airflowReduced airflow can cause more heat buildup than normal on the case.
  • PossibleCooling fan not working properlyIf the fan that helps dissipate heat isn't running well, the case can get hotter than usual.
  • Less commonComponent overheating internallyA specific hot spot on the case, especially if new, could indicate an internal part running hotter than it should.

What to do

  1. Check that the vents on the back, sides, or top (depending on your model) aren't blocked by nearby items or built-in cabinetry.
  2. Dust off any visible vent openings with a soft brush or vacuum attachment.
  3. Listen for the internal cooling fan running during and briefly after use; if you don't hear any fan noise at all, this could point to a fan failure.
  4. Feel whether the heat is spread generally across the case (more likely normal) versus concentrated in one small hot spot (worth more concern).
  5. Give the microwave a few minutes of clear space and normal use to see if heat levels seem consistent with past experience.
  6. If a specific area is unusually hot or the cooling fan seems to not be running, have a technician inspect the ventilation and internal components.

Tools and parts

  • Soft brush or vacuum

When to call a pro

If a cooling fan seems absent or a specific hot spot develops, have a technician inspect the ventilation and internal components.

Safety

Use caution

A specific, unusually hot spot on the case (rather than general warmth) can indicate an internal issue worth having checked promptly.

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.