Error Code F4

Lower oven sensor open

Also displayed as: F4

How to Fix

1. 1

   Unplug the unit.

2. 2

   Check if any connector is disconnected or loose: inspect lower sensor connection at CN60 (pins 4 and 5) and CN61 (pins 5 and 6) of Main PCB.

3. 3

   If connector is loose, reconnect and retest.

4. 4

   Measure lower thermistor resistance. Normal: approximately 1.09 kΩ ±10% at 77°F (25°C). Infinite resistance = open/failed sensor.

5. 5

   If thermistor resistance is abnormal, replace the lower oven temperature sensor.

6. 6

   Plug in unit and verify in test mode. Display should show current oven temp between 70°F and 90°F at room temperature.

7. 7

   If sensor is normal but F4 persists, replace the Main PCB.

This Error Applies To

LG LDG431 Series Ovens & Ranges