LG Refrigerators

Error Code F dH

Defrost heater failure

Moderate

Address soon - your appliance may not work properly

How to Fix

  1. 1

    Check door gasket for damage. If gasket is damaged, replace the door gasket.

  2. 2

    Check defrost heater resistance at CON9 pins 5–13 (Test Mode 1, 0V expected when heater off). Target resistance 42–50 ohms for the combined circuit. If not in range, check Fuse-M continuity (should read 0 ohms). If Fuse-M is open (infinite), replace Fuse-M. If heater is open, replace heater.

  3. 3

    If defrost sensor resistance is not ~22k ohms (at room temp) or is open, replace the defrost sensor/controller assembly.

  4. 4

    Enter Test Mode 3 (push test button 3 times). Check voltage at CON9 pins 5–13; expected 112–116V during defrost. If voltage is not present, replace Main PCB.

  5. 5

    Enter Test Mode 1 (push test button 1 time). Check voltage at CON9 pins 5–13; expected 0V when not in defrost. If voltage is not 0V, replace Main PCB.

  6. 6

    If all checks pass, explain to customer — unit is operating normally.

This Error Applies To

LG LL31H6530S Series Refrigerators

Service manual exact match: LL31H6530S

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