GE Microwave F5 Error Code — What It Means
The F5 code on a GE microwave means the control has detected a shorted humidity sensor. GE’s official fault-code table defines F5 as a shorted humidity sensor in the microwave control system. The humidity sensor monitors moisture during cooking cycles. When the control sees an electrical short in that sensor circuit, it throws F5 and stops normal operation to prevent damage or incorrect cooking.
Sometimes the sensor itself has failed internally and is reading as a dead short. Other times a damaged wire, corroded connector, or a problem on the control board input circuit makes the control think the sensor is shorted even when it is not. Either way, F5 tells you the issue is in the humidity sensor circuit.
Common Causes
- Failed humidity sensor The sensor has shorted internally and reads zero or near-zero resistance, triggering the fault code.
- Damaged or pinched sensor wiring A wire in the humidity sensor harness has lost insulation or been crushed, creating a short to ground or another wire.
- Loose or corroded sensor connector Moisture or arcing at the connector terminals can bridge pins and mimic a shorted sensor.
- Control board input fault A failed component on the control board’s sensor input circuit can falsely detect a short even when the sensor is good.
Step-by-Step Fix
- Disconnect power at the circuit breaker or unplug the microwave and wait at least 30 seconds to clear the fault from memory.
- Restore power and test the microwave to see if F5 returns immediately or during a cooking cycle.
- Unplug again and remove the outer cabinet panels to access the humidity sensor, usually mounted near the vent or cavity.
- Inspect the humidity sensor connector for corrosion, burn marks, or loose pins and clean or reseat it as needed.
- Check the sensor harness from the sensor to the control board for pinched, melted, or bare wire insulation.
- Test the humidity sensor with a multimeter according to your model’s service data or replace it if it reads shorted or out of specification.
- Reassemble the microwave, restore power, and run a test cycle to confirm the F5 code does not reappear.
Parts Often Needed
| Part | Notes |
|---|---|
| Humidity Sensor | Amazon | Match the part number on your existing sensor or look up your exact GE microwave model number. |
| Wire Harness (Sensor to Control) | Amazon | Only needed if the wiring is damaged or connectors are melted beyond cleaning. |
| Electronic Control Board | Amazon | Required if sensor and wiring test good but F5 persists, indicating a board-level fault. |
When to Call a Pro
If the power-cycle reset does not clear F5 or the code returns immediately, a trained service technician should diagnose and repair the issue. Testing the humidity sensor requires a multimeter and access to your model’s service specifications. Working inside a microwave cabinet also exposes you to high-voltage capacitor circuits that can hold a dangerous charge even when unplugged. If you are not comfortable with electrical testing or disassembly, call a qualified appliance repair technician to inspect the sensor, wiring, and control board safely.