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Error code reference

LG Refrigerator Error Code WT-Sensor

Water tank sensor error

LG codesLG refrigerator codes

Water tank sensor error - water tank temperature sensor has failed.

First step from the service manual

Disconnect CON6 and measure resistance between pins 9 & 10 (GY to GY); expected 6 ~ 300 kΩ.

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

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What WT-Sensor means on a LG refrigerator

The WT-Sensor error on an LG refrigerator indicates a failure in the water tank temperature sensor circuit. This sensor monitors the temperature of the internal water tank, which is used to supply chilled water through the dispenser. When the refrigerator's control board detects a signal from this sensor that falls outside the acceptable range, either an open circuit, a short, or a resistance reading that does not correspond to a valid temperature, it triggers the WT-Sensor fault code.

The primary diagnostic procedure involves disconnecting connector CON6 and measuring the resistance between pins 9 and 10, both identified as GY (gray) wires. A healthy sensor will read between 6 kΩ and 300 kΩ depending on the current temperature of the water tank. A reading of zero ohms indicates a short circuit within the sensor or wiring harness, while an open circuit reading (infinite resistance or OL) points to a broken sensor element or a severed wire. If the resistance falls within the specified range, the sensor itself may be functioning correctly and the fault could lie in the wiring between CON6 and the main control board.

Common root causes include a failed NTC thermistor element inside the sensor, corroded or damaged connector pins at CON6, and wiring damage along the harness that runs to the water tank assembly. Because the water tank is located in a refrigerated environment with some moisture exposure, connector corrosion is a realistic failure mode over time. Confirming whether the fault is in the sensor or the harness requires the CON6 resistance test as the critical first step before any parts are ordered.

Source: manufacturer service documentation.

Common causes of WT-Sensor

  1. 01

    Failed water tank temperature sensor

    Part replacement

    The NTC thermistor inside the sensor degrades over time and produces a resistance reading outside the 6 to 300 kΩ range, or an open/short circuit. Confirmed by measuring resistance between pins 9 and 10 of CON6.

  2. 02

    Corroded or damaged connector pins at CON6

    Wiring / connection

    Moisture exposure in the refrigerator compartment can corrode the GY wire pins at CON6, causing intermittent or complete signal loss. Visually inspect pins 9 and 10 for oxidation, bent pins, or debris.

  3. 03

    Damaged wiring harness

    Part replacement

    The wiring between CON6 and the water tank sensor can develop breaks or chafing, resulting in an open circuit. A continuity check along the harness length will identify any break points.

  4. 04

    Loose connector at CON6

    Wiring / connection

    A connector that is not fully seated at CON6 can produce an intermittent or false sensor fault. Disconnecting and firmly reseating the connector may resolve the error if no physical damage is present.

  5. 05

    Faulty main control board

    Part replacement

    If the sensor and wiring both test within specification, the control board may be misreading the sensor signal due to a failed input circuit. This is the least common cause and should only be considered after sensor and harness are confirmed good.

See the test procedure for each cause

Frequently asked questions about WT-Sensor

What does WT-Sensor mean on a LG refrigerator?
The WT-Sensor code indicates that the water tank temperature sensor has failed or is sending a signal outside the acceptable range to the control board. This sensor monitors the temperature of the internal chilled water tank. The fault can be caused by a bad sensor, corroded connector pins, or a damaged wiring harness. A resistance test at connector CON6, pins 9 and 10, is the standard first step to diagnose the problem.
Can I fix the WT-Sensor error myself?
A knowledgeable DIYer with a multimeter can perform the resistance test at CON6 pins 9 and 10 to determine whether the sensor or wiring is the cause. If the resistance reads outside 6 to 300 kΩ, or shows an open or short circuit, the sensor or harness will need to be replaced. Reseating the connector is also a straightforward first step that requires no special tools. However, if the fault points to the main control board, professional diagnosis is recommended.
Is the WT-Sensor error dangerous?
The WT-Sensor error is not a safety hazard in most cases. It indicates a sensor circuit failure rather than a refrigerant or electrical safety issue. The most likely impact is that the chilled water dispenser may not function correctly. Food preservation in the main refrigerator and freezer compartments is generally not affected by this specific fault.
How much does it cost to repair the WT-Sensor error on an LG refrigerator?
Repair costs vary depending on the root cause. Replacing the water tank temperature sensor typically costs between $20 and $80 for the part, plus labor if a technician is hired. A wiring harness repair or connector replacement may fall in a similar range. If the main control board is at fault, parts alone can range from $100 to $300 or more. Getting a diagnosis before ordering parts will help avoid unnecessary expense.
Will resetting the refrigerator clear the WT-Sensor error?
A power reset may temporarily clear the WT-Sensor code, but if the underlying sensor or wiring fault is still present, the error will return. Resetting is not a fix, only a way to confirm whether the fault is intermittent or persistent. A proper diagnosis using the CON6 resistance test is necessary to resolve the error permanently. Continuing to reset the unit without repair may mask an ongoing fault in the water tank circuit.

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