How do I fix error code F dH on a LG refrigerators?

1. undefined: Step 1: Check door gasket for damage — if damaged, replace door gasket. 2. undefined: Step 2: Measure defrost control assembly Fuse-M resistance (1) to (2) — expected 0 to 0.1 ohm; if infinite (open), Fuse-M is bad — replace defrost control assembly. 3. undefined: Step 3: Measure defrost heater resistance at CON9 pins 5-13 in Test Mode 1 — expected 42 to 50 ohm (some sources indicate 62 to 70 ohm for sheath heater). If resistance = infinity, heater is open — replace sheath heater. 4. undefined: Step 4: Enter Test Mode 3 (press test button 3 times) and measure voltage at CON9 pins 5-13 — expected 112 to 116V; if 0V, proceed to Step 5. 5. undefined: Step 5: Enter Test Mode 1 and measure voltage at CON9 pins 5-13 — expected 0V; if not 0V, replace Main PCB. 6. undefined: Step 6: If heater voltage in Test Mode 3 is correct (112-116V) but defrost is not occurring, verify defrost sensor — measure resistance at CON8 pins 26-25; if open (infinity), replace defrost sensor. 7. undefined: Step 7: If all checks are normal, explain to customer.

LG Refrigerators2023–present

Error Code F dH

Defrost Heater Error — Defrost Sensor Did Not Reach 40°F (5°C) Within 80 Minutes

Moderate

Address soon - your appliance may not work properly

What This Means

Disconnection or open circuit of thermal fuse (Fuse-M); Defective defrost heater (sheath heater); Defective heater relay on Main PCB; Drain tube blockage

How to Fix

1
Step 1: Check door gasket for damage — if damaged, replace door gasket.
2
Step 2: Measure defrost control assembly Fuse-M resistance (1) to (2) — expected 0 to 0.1 ohm; if infinite (open), Fuse-M is bad — replace defrost control assembly.
3
Step 3: Measure defrost heater resistance at CON9 pins 5-13 in Test Mode 1 — expected 42 to 50 ohm (some sources indicate 62 to 70 ohm for sheath heater). If resistance = infinity, heater is open — replace sheath heater.
4
Step 4: Enter Test Mode 3 (press test button 3 times) and measure voltage at CON9 pins 5-13 — expected 112 to 116V; if 0V, proceed to Step 5.
5
Step 5: Enter Test Mode 1 and measure voltage at CON9 pins 5-13 — expected 0V; if not 0V, replace Main PCB.
6
Step 6: If heater voltage in Test Mode 3 is correct (112-116V) but defrost is not occurring, verify defrost sensor — measure resistance at CON8 pins 26-25; if open (infinity), replace defrost sensor.
7
Step 7: If all checks are normal, explain to customer.