Error Code F dH

Defrost Heater Error — defrost heater or defrost control circuit failure

Also displayed as: F dH

How to Fix

1. 1

   Step 1: Inspect door gasket for damage. If damaged, replace the door gasket.

2. 2

   Step 2: Enter Test Mode 3 (push test button 3 times). Measure voltage at CON3 pins 2–9. If voltage is 112V–116V, the heater circuit is energized — proceed to Step 3.

3. 3

   Step 3: Check Fuse-M resistance. Expected resistance is 34–42Ω. If Fuse-M measures open (infinity), the fuse has blown — replace the defrost heater assembly (includes Fuse-M).

4. 4

   Step 4: Check defrost sensor resistance. Expected is approximately 22kΩ at room temperature. If resistance is 22kΩ or open (OL), replace the defrost sensor.

5. 5

   Step 5: Enter Test Mode 1 (push test button 1 time). Measure voltage at CON3 pins 2–9. If voltage is 0V when it should be 0V in test mode 1, the PCB output is correct.

6. 6

   Step 6: If voltage at CON3 in Test Mode 3 is not 112V–116V, replace the Main PCB.

7. 7

   Step 7: If heater voltages are correct and sensor/fuse pass, but defrost still fails, replace the defrost heater assembly.

8. 8

   Step 8: Explain to customer once repair is verified.

This Error Applies To

LG LRFCS29D6S Series Refrigerators