Safety first: Turn off power at the breaker before any disassembly.

Step 1 – Visual inspection: Locate the oven temperature sensor inside the oven. Inspect the sensor and its wiring for signs of melting, chafing, or contact with metal surfaces.
Step 2 – Disconnect and test sensor: Remove the sensor mounting screws, pull it forward, and disconnect the plug. With a multimeter, measure resistance across the sensor. A shorted sensor will read near 0 Ω. If so, replace the sensor.
Step 3 – Check for shorts to ground: With the sensor unplugged, check resistance from each sensor wire to the oven chassis. Any low resistance indicates a shorted harness. Repair or replace the harness.
Step 4 – Inspect control board: If the sensor and harness are good, the control board’s sensor circuit may be shorted internally. Replace the electronic oven control board.

Warning: Do not operate the oven with a known short in the sensor circuit; this can damage the control board further.

Oven displays F4 and may not heat correctly; error may appear intermittently during use.

Possible Causes