Oven does not heat correctly, display shows F3, sometimes accompanied by erratic temperature swings.

Safety first: Disconnect mains power before removing the control panel or back cover.

• Access control board: Remove the top panel or front control panel (depending on model) to reach the main electronic control board.
• Reseat sensor connector: Locate the two-wire connector from the oven temperature sensor. Unplug and replug it several times to clean the contacts. Ensure it is fully seated and locked.
• Check cable continuity: With the sensor disconnected at both ends, use a multimeter to check continuity of each conductor from the sensor plug to the control board plug. Any open or high-resistance reading indicates a damaged cable that must be replaced.
• Inspect for corrosion: Look for green/white corrosion or discoloration on pins. Clean gently with contact cleaner and a soft brush.
• Test again: Reassemble, restore power, and test the oven. If F3 returns and wiring and sensor test good, the control board's sensor input circuit is likely defective and the board should be replaced.