LG Compressor Run-On / Control Relay Stuck

Wine cooler runs continuously without shutting off, yet temperature is near or at setpoint.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Stuck compressor relay on main PCB, Misreading temperature sensor, Poor door seal causing constant heat gain, Control firmware issue

How to Fix / Troubleshooting

Safety: Unplug the unit before accessing the control board or sensors.

Steps:

  • 1. Confirm temperature: Use an independent thermometer to verify actual cabinet temperature.
  • 2. Check door gasket and seal: Repair or replace gasket if leaking, as constant warm air infiltration can keep the compressor running.
  • 3. Test cabinet thermistor: Measure resistance and compare to expected values. Replace if out of spec.
  • 4. Inspect control board: Look for signs of a welded or burnt compressor relay. If the compressor runs even when the unit is turned off at the control, the relay is likely stuck.
  • 5. Replace main PCB: Install a new LG main control board if the relay is faulty or the board misreads temperature.
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Repair Difficulty

Hard 4/5

Required Part

Main Control Board
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