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Error code reference

LG Refrigerator Error Code dH

Failure of defrost mode

LG codesLG refrigerator codes

Failure of defrost mode — defrost sensor doesn't reach 8°C within 2 hours after starting defrost, indicating snapping of defrost heater or temperature fuse, or pullout of connector.

First step from the service manual

Check defrost heater, temperature fuse, and connector; indicated minimum 2 hours after failure occurs.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What dH means on a LG refrigerator

The dH error code on an LG refrigerator indicates a defrost system failure. Specifically, the control board has determined that the defrost sensor did not reach the required threshold of 8°C within a 2-hour window after the defrost cycle was initiated. This code is not triggered immediately at the onset of a problem. It appears only after the full 2-hour period has elapsed without the sensor reaching the target temperature, which means the underlying issue has been present for at least that long before the code becomes visible.

The defrost system relies on a heater element to melt frost accumulation on the evaporator coils. A thermal fuse, also called a temperature fuse, is wired in series with the heater to protect against overheating. If either the heater element itself has failed open, or the thermal fuse has blown, the heater will not produce heat during the defrost cycle. The defrost sensor, which monitors evaporator temperature, will then never register the 8°C rise needed to confirm a successful defrost, triggering the dH code.

A disconnected or damaged wiring connector is also a recognized cause. If the connector supplying power to the heater or fuse has pulled out or corroded, the circuit is broken and the heater cannot operate. Diagnosis should focus on checking continuity of the defrost heater element, continuity of the thermal fuse, and secure seating of all connectors in the defrost circuit. A blown thermal fuse is not resettable and requires physical replacement.

Source: manufacturer service documentation.

Common causes of dH

  1. 01

    Failed defrost heater element

    Part replacement

    The heater element has burned out and no longer produces heat during the defrost cycle. You can confirm this by testing the heater for continuity with a multimeter. An open circuit reading confirms failure.

  2. 02

    Blown thermal fuse

    Part replacement

    The thermal fuse is wired in series with the defrost heater and blows when it detects an over-temperature condition. Once blown, it permanently breaks the circuit and must be replaced. Test it for continuity to confirm failure.

  3. 03

    Disconnected or pulled-out wiring connector

    Wiring / connection

    A connector in the defrost circuit may have come loose or pulled away from its terminal, interrupting power to the heater or fuse. Inspect all connectors in the defrost circuit for secure seating and signs of corrosion or damage.

  4. 04

    Faulty defrost sensor

    Part replacement

    If the defrost sensor itself is malfunctioning, it may fail to register the correct temperature even when the heater is operating normally, causing a false dH error. Test the sensor for proper resistance values at a known temperature.

See the test procedure for each cause

Frequently asked questions about dH

What does dH mean on a LG refrigerator?
The dH code means the refrigerator's defrost system failed to complete a defrost cycle properly. The defrost sensor did not reach 8°C within 2 hours of the defrost cycle starting, which tells the control board that the heater is not generating heat. This is most commonly caused by a failed defrost heater element, a blown thermal fuse, or a disconnected wiring connector in the defrost circuit. The code only appears after the full 2-hour defrost window has elapsed.
How do I fix the dH error code on my LG refrigerator?
Start by checking the defrost heater, thermal fuse, and all connectors in the defrost circuit. Use a multimeter to test both the heater element and the thermal fuse for continuity. A reading of no continuity on either component means it has failed and needs to be replaced. If the connectors appear loose or corroded, reseat or clean them and recheck operation.
Will resetting my LG refrigerator clear the dH error code?
A power reset may temporarily clear the code from the display, but the error will return if the underlying defrost system fault is not repaired. Because the code only triggers after a full failed 2-hour defrost cycle, it will reappear the next time the defrost cycle runs and fails again. The root cause, such as a faulty heater or blown fuse, must be diagnosed and corrected to resolve the error permanently.
Is the dH error code on an LG refrigerator a safety concern?
The dH error itself does not represent an immediate safety hazard, but it does indicate the freezer is not defrosting correctly. Over time, frost will accumulate on the evaporator coils and restrict airflow, which will progressively reduce cooling performance in both the freezer and fresh food sections. Food spoilage becomes a risk if the defrost problem is left unaddressed for an extended period.
How much does it cost to repair a dH error on an LG refrigerator?
Repair costs vary depending on which component has failed. A thermal fuse is a relatively inexpensive part, with the component itself typically ranging from a few dollars to around $20, while a defrost heater element may cost between $20 and $60 for the part. If you hire a technician, expect to add labor charges on top of parts costs, which can bring the total repair into the range of $100 to $250 or more depending on your location and the specific model.

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