The F4 error code is the opposite of F3 — it indicates a shorted (closed circuit) oven temperature sensor. The control board detects a resistance value from the sensor that is too low, indicating a short circuit in the sensor or its wiring. This causes incorrect temperature readings, usually reading falsely high temperatures.
Causes
- Shorted oven temperature sensor probe
- Wiring short in the sensor harness (often due to wire insulation melted by heating element)
- Moisture or grease contaminating the sensor connector
Troubleshooting
- Visually inspect the temperature sensor and its wiring for burn marks, melted insulation, or contact between wires.
- Unplug and reset. If F4 returns, the sensor requires professional testing (resistance measurement) and likely replacement.