Magic Chef oven shows F4 error, often intermittently, sometimes when the oven is hot or during preheat.

Safety first: Turn off power at the breaker before removing panels or touching wiring.

• Test the sensor: Remove the oven temperature sensor from the rear wall inside the cavity. Disconnect it and measure resistance at room temperature. A shorted sensor will read very low resistance (near 0 Ω). Replace if out of spec.
• Inspect wiring for shorts: Follow the sensor wires through the rear of the oven. Look for spots where insulation is rubbed through and touching metal. Repair with high-temperature wire and ceramic wire nuts as needed.
• Check connectors: Inspect the sensor connector at the EOC for corrosion, moisture, or carbon tracking. Clean or replace the connector if damaged.
• Replace EOC if necessary: If the sensor and wiring are confirmed good, the EOC’s sensor input may be shorted internally. Replace the electronic oven control.

When to call a technician: If you find extensive heat damage to wiring or insulation, professional repair is recommended.