Error Code F dH

Defrost Heater Error — defrost temperature does not rise above 47°F (8°C) within expected time; caused by door gasket failure, defrost heater open, blown Fuse-M, or poor PCB relay

Also displayed as: F dH

How to Fix

1. 1

   Step 1: Visually inspect the door gasket for damage. If door gasket is damaged or not sealing, replace the door gasket.

2. 2

   Step 2: Measure Fuse-M resistance across its 2 housing pins. If resistance is not approximately 0 Ω (i.e., it is open/infinite), the Fuse-M has blown — replace the defrost controller assembly.

3. 3

   Step 3: Measure Defrost Sensor resistance across its 2 housing pins. If resistance is approximately 22 kΩ at room temperature (or matches table at other temps) it is good. If resistance is infinite (open) or 0 (shorted), replace the defrost controller assembly.

4. 4

   Step 4: Enter Test Mode 3 (press test button 3 times — '33 33' displayed). Measure voltage at CON3 between 2nd pin and 9th pin. If voltage is 112V–116V, the PCB is supplying power correctly — proceed to check the heater.

5. 5

   Step 5: If Test Mode 3 shows 112V–116V at CON3 but heater resistance is open (not 34–42 Ω), replace the defrost heater (sheath heater).

6. 6

   Step 6: Enter Test Mode 1 (press test button 1 time — everything on). Measure voltage at CON3 between 2nd pin and 9th pin. If voltage is not 0V in Test Mode 1, replace the Main PCB.

7. 7

   Step 7: If none of the above tests reveal a fault, replace the Main PCB.

This Error Applies To

LG LRFWS2906 Series Refrigerators