Dacor oven shows F4 and will not start or maintain temperature.

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

• Test sensor: Remove the oven temperature sensor connector and measure resistance at room temperature. If the reading is very low (near 0 Ω) or significantly below 1000 Ω, the sensor is shorted and must be replaced.
• Inspect harness for shorts: Follow the sensor wires from the cavity to the control board. Look for areas where insulation is melted, pinched, or touching metal. Repair or replace the harness as needed.
• Check at control board: With the sensor disconnected, measure resistance at the control board connector. If it still reads shorted, the harness or board is at fault.
• Replace EOC if needed: If the sensor and harness are good but F4 remains, the control board sensor circuit is likely damaged and requires replacement.

Warning: Do not operate the oven with a known sensor fault; inaccurate temperature control can cause overheating and damage.