Error Code F9

Oven not heating — oven temperature does not rise more than 10°F above starting temperature within 5 minutes of cooking start (excludes Proof, Warm, and Easy Clean modes)

Also displayed as: F9

How to Fix

1. 1

   Unplug the unit.

2. 2

   Check all electrical wiring connections at Main PCB, igniter connectors, and safety valve connectors — reconnect or fix any loose/disconnected wiring.

3. 3

   Measure resistance of the bake igniter (Conv. Bake igniter, type SIC): Normal is 50Ω to 500Ω at room temperature. If infinite (open), replace the igniter.

4. 4

   Measure resistance of the broil igniter (Norton type): Normal is 45Ω to 400Ω at room temperature. If infinite (open), replace the igniter.

5. 5

   Measure resistance of the oven thermistor at pins 4 and 5 of CN60 on Main PCB. Normal is approximately 1.09 kΩ at 25°C. If abnormal, replace the oven sensor.

6. 6

   Plug in the unit and verify thermistor reading in test mode: press CLEAR, press BAKE+BROIL simultaneously, press BAKE+BROIL again, press NUM 3. Normal room temp reading is 70°F to 90°F. If abnormal, replace the Main PCB.

7. 7

   If all above components test normal but F9 persists, replace the Main PCB.

This Error Applies To

LG LRG4115ST Series Ovens & Ranges