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Error code reference

LG Refrigerator Error Code dH R

Poor Refrigerator Defrost

LG codesLG refrigerator codes

Poor Refrigerator Defrost - 50 minutes after starting defrost, if defrost sensor doesn't rise above 10°C. Possible snapping of defrost heater, temperature fuse failure, poor heater relay operation, or blocked drain.

First step from the service manual

Check the door gasket, then check the defrost control parts (Fuse-M, Defrost Heater, Defrost Sensor).

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

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What dH R means on a LG refrigerator

The dH R error code on an LG refrigerator indicates a refrigerator compartment defrost failure. Specifically, the control board triggers this code when 50 minutes have elapsed since the defrost cycle began and the defrost sensor has not detected a temperature rise above 10°C. This threshold exists because a properly functioning defrost system should generate enough heat from the defrost heater to warm the evaporator coils and surrounding sensor well within that time window. When the sensor reading stays below 10°C, the system determines that defrost is not occurring effectively.

The defrost system in the refrigerator compartment consists of several interdependent components: the defrost heater, the thermal fuse (Fuse-M), the defrost sensor (thermistor), and the heater relay on the control board. A failure in any one of these can prevent adequate heat from reaching the evaporator. A broken defrost heater element will produce no heat at all. A blown thermal fuse will interrupt the circuit even if the heater is intact. A faulty heater relay may fail to energize the heater circuit when commanded by the control board. The defrost sensor itself, if reading incorrectly, may report a falsely low temperature even when defrost is occurring normally.

Beyond component failures, a compromised door gasket can allow warm, humid air into the refrigerator compartment continuously, causing excessive frost accumulation on the evaporator that overwhelms the defrost cycle's capacity. A blocked or frozen drain can also contribute by preventing meltwater from draining properly, leading to ice buildup that insulates the evaporator and prevents the sensor from reaching the 10°C threshold within the allotted defrost window.

Source: manufacturer service documentation.

Common causes of dH R

  1. 01

    Failed Defrost Heater

    Part replacement

    The defrost heater element can burn out or snap, leaving the evaporator coils with no heat source during the defrost cycle. Inspect the heater for visible breaks and check for continuity with a multimeter; a broken heater will show no continuity.

  2. 02

    Blown Thermal Fuse (Fuse-M)

    Part replacement

    The thermal fuse is a one-time safety device that interrupts the defrost circuit if temperatures exceed a safe limit. Once blown, it must be replaced; test it for continuity with a multimeter as a blown fuse will read open.

  3. 03

    Faulty Defrost Sensor

    Part replacement

    If the defrost thermistor is reading temperatures inaccurately, the control board may never register that the 10°C threshold has been reached, even if the heater is working. Check the sensor's resistance value against the specification for the expected temperature range.

  4. 04

    Poor Door Gasket Seal

    Part replacement

    A worn or damaged door gasket allows warm, moist air to continuously enter the refrigerator compartment, causing frost to accumulate faster than the defrost cycle can clear it. Inspect the gasket for tears, gaps, or sections that no longer make firm contact with the cabinet.

  5. 05

    Heater Relay Failure or Blocked Drain

    Part replacement

    A heater relay on the control board that does not close properly will prevent the defrost heater from receiving power even when commanded. Separately, a drain blocked with ice or debris can cause meltwater to refreeze on the evaporator, adding to frost load and preventing the sensor from rising above 10°C.

See the test procedure for each cause

Frequently asked questions about dH R

What does dH R mean on a LG refrigerator?
The dH R code means the refrigerator compartment defrost cycle failed to raise the defrost sensor temperature above 10°C within 50 minutes of starting. This indicates a problem with the defrost heating circuit or related components. Possible causes include a failed defrost heater, a blown thermal fuse, a defective defrost sensor, a faulty heater relay, or a blocked drain. A poor door gasket seal can also contribute by allowing excessive frost buildup.
How do I fix the dH R error on my LG refrigerator?
Start by inspecting the door gasket for gaps or damage that could let in warm air. Next, test the defrost heater, thermal fuse (Fuse-M), and defrost sensor for continuity and correct resistance using a multimeter. If the heater or fuse has failed, replacing the faulty component should resolve the error. If those components test good, the heater relay on the control board may need evaluation.
Will resetting my LG refrigerator clear the dH R error code?
Resetting the refrigerator by unplugging it for a few minutes may temporarily clear the dH R code, but the error will return if the underlying defrost system problem is not repaired. The code is triggered by a real performance failure detected during the defrost cycle, so a reset alone is not a fix. Address the root cause first to prevent the code from recurring and to avoid ice buildup on the evaporator coils.
Is it safe to keep using my LG refrigerator while it shows the dH R error?
Continued use with an active dH R error is not recommended for extended periods. Without a functioning defrost cycle, frost will accumulate on the evaporator coils and progressively restrict airflow, causing the refrigerator to lose cooling capacity. Food safety can become a concern if temperatures rise. It is best to diagnose and repair the defrost system as soon as possible.
How much does it cost to repair the dH R error on an LG refrigerator?
Repair costs depend on which component has failed. A replacement thermal fuse or defrost sensor is generally an inexpensive part, with DIY repair costs typically in the range of $10 to $40 for the part alone. A defrost heater assembly tends to run $30 to $80 in parts. If a control board replacement is needed due to a faulty heater relay, parts and labor combined can range from $150 to $350 or more depending on the model and service rates in your area.

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