GE · Microwave Serious

F1 — Open Thermal Sensor (Overheating)

F1 means the thermal sensor read open due to excessive heat in the cavity — an overheat protection fault.

Keep using it?
Limited use only
DIY difficulty
Moderate

How to fix it

  1. Unplug the microwave for a minute to reset and let it cool.
  2. Make sure the top/rear vents are not blocked (OTR units).
  3. If F1 returns, test/replace the thermal sensor.

Why it happens

Typical signs: Microwave stops/beeps · F1 on the display · Unit ran hot

  • Blocked vents / overheating Restricted airflow (especially on over-the-range units) traps heat.
  • Failed (open) thermal sensor The cavity thermal sensor has failed open.
  • Sensor wiring fault A broken connector or wire to the sensor.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • GE Microwave Thermal Sensor Common replacement
    Amazon →

More GE microwave codes

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Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: products.geappliances.com.