If your LG LMX25981ST refrigerator is not cooling properly, making unusual noises, leaking water, or having trouble with ice or water dispensing, the cause is often reduced airflow, skipped maintenance, or failure of one of the refrigerator’s main cooling or water-system components.

This guide is built like a structured repair manual. It helps you diagnose the problem logically, understand why it is happening, work through the fix step by step, identify the exact part most likely at fault, and decide whether the repair is a realistic DIY job or something better handled by a technician.

Step-by-Step Troubleshooting and Repair Guide

1. Check Power Supply

Why this step matters: Even a partial power issue can make the refrigerator behave strangely. Lights or fans may work while the compressor does not start.

Deep diagnostic steps:

1. Check whether the display panel is on.

2. Open the door and confirm the interior light comes on.

3. Plug another appliance into the same outlet to verify power.

4. Inspect the circuit breaker panel and reset the breaker if needed.

Advanced insight: If the lights work but the unit is not cooling, the issue is likely internal, such as the relay, compressor, or control board. If there is no power at all, focus on the electrical supply or main board.

2. Evaluate Cooling Performance and Airflow

Why this is critical: This refrigerator depends on moving cold air from the freezer into the fresh-food section. If airflow is restricted, cooling performance drops quickly.

Detailed checks:

1. Confirm the temperature settings are about 37°F for the refrigerator and 0°F for the freezer.

2. Feel for airflow coming from the vents inside the refrigerator section.

3. Check for overpacked shelves that may block vents.

4. Look for frost or ice blocking internal air passages.

Pro insight: If the freezer is cold but the refrigerator is warm, the most likely cause is an airflow or evaporator fan issue.

3. Clean Condenser Coils

Why this matters: Dirty condenser coils reduce heat release and make the compressor work harder, which weakens cooling performance.

Step-by-step:

1. Unplug the refrigerator.

2. Pull the unit away from the wall.

3. Locate the coils at the rear or lower section.

4. Use a vacuum with a brush attachment or a coil cleaning brush to remove dust and pet hair thoroughly.

Expert tip: Dirty coils can reduce efficiency significantly and are one of the highest-impact maintenance fixes.

4. Inspect Door Seals

Why this matters: Even a small gasket leak can lead to constant compressor operation, frost buildup, and unstable temperatures.

Detailed testing:

1. Inspect the door gaskets visually for cracks, tears, or warped sections.

2. Run your hand around the door edge and feel for escaping cold air.

3. Perform a paper test by closing the door on a sheet of paper and checking for resistance.

4. Look for moisture or condensation around the door frame.

Fix: Clean the gasket first. If it still does not seal tightly, replace it.

5. Check the Evaporator Fan Motor

Role of this part: The evaporator fan pushes cold air from the freezer into the refrigerator section.

Symptoms: Freezer stays cold while the refrigerator section gets warm, airflow is weak, or the fan is silent or buzzing.

Detailed steps:

1. Unplug the refrigerator.

2. Remove the rear panel inside the freezer compartment.

3. Inspect the fan for ice blockage or broken blades.

4. Spin the blade by hand to check for binding.

5. Test the fan motor with a multimeter for continuity and replace it if defective.

Key insight: When airflow stops, the refrigerator section almost always fails before the freezer does.

6. Inspect the Defrost System

Why this is important: Frost buildup on the evaporator blocks airflow even when the refrigeration system itself is still working.

Components involved:

• Defrost heater

• Defrost thermostat

• Defrost sensor

• Control board

Symptoms: Ice on the back panel, the refrigerator slowly getting warmer, or water leaking after thawing.

Full repair process:

1. Unplug the refrigerator.

2. Open the freezer and remove the rear panel.

3. Inspect the evaporator coil area. If it is fully iced over, the defrost system is likely failing.

4. Manually defrost the unit by leaving it unplugged for 12 to 24 hours or using a hair dryer carefully.

5. Test the defrost heater and thermostat for continuity and replace the failed part.

Expert insight: If frost returns within a few days after manual defrosting, the defrost system is almost certainly the issue.

7. Diagnose the Ice Maker System

Why the ice maker fails: Most ice maker issues come from water supply problems, clogged filters, frozen lines, or failed valves.

Step-by-step:

1. Check that the water supply valve is fully open.

2. Inspect the water line for kinks or freezing.

3. Replace the water filter if it is old or restricted.

4. Test the water inlet valve and reset the ice maker if your model supports it.

Advanced insight: Slow ice production often points to a clogged filter, while no ice at all more often points to the valve or the ice maker assembly.

8. Replace the Water Filter

Why this matters: A clogged water filter reduces water flow, affects ice production, and can cause poor water taste.

Proper process:

1. Remove the old filter.

2. Install the new filter securely.

3. Flush 2 to 3 gallons of water through the dispenser.

4. Reset the filter indicator if applicable.

Important note: Flushing is necessary to remove loose carbon residue that can cause cloudy water initially.

9. Check the Thermistor

Why this is critical: The thermistor tells the control system what temperature the refrigerator is actually reading. Incorrect readings lead to incorrect cooling cycles.

Symptoms: The refrigerator gets too warm, too cold, or swings unpredictably in temperature.

Steps:

1. Locate the thermistor in the appropriate compartment.

2. Test its resistance with a multimeter.

3. Compare the reading to the correct temperature-resistance chart for the model.

4. Replace the sensor if it is out of specification.

10. Diagnose the Compressor and Start Relay

Why this matters: The compressor is the heart of the cooling system, and the start relay helps it turn on.

Symptoms: Clicking sounds, no cooling, or a compressor that tries to start but does not run.

Steps:

1. Listen for clicking, which suggests the compressor is trying to start.

2. Remove the start relay from the compressor.

3. Shake the relay gently. If it rattles, it is likely bad.

4. Replace the relay and retest the refrigerator.

Critical insight: A failed relay is a relatively inexpensive repair. A failed compressor is a major repair and usually requires professional service.

11. Reassemble and Monitor

Final validation: After completing repairs, put the refrigerator back together and confirm that the fix actually holds.

After repairs:

1. Reinstall all panels and covers.

2. Plug the refrigerator back in.

3. Allow up to 24 hours for temperatures to stabilize fully.

4. Monitor temperature, airflow, ice production, and noise levels.

Parts You May Need Based on Diagnosis

• Evaporator fan motor

• Water filter

• Door gasket

• Ice maker assembly

• Water inlet valve

• Defrost heater

• Defrost thermostat

• Thermistor

• Start relay

• Control board

Repair vs. Replace Decision Guide

Repair if:

• The refrigerator is under 10 years old

• The problem is limited to parts such as the fan, filter, gasket, or relay

• The repair cost is still reasonable

Replace if:

• The compressor has failed

• Multiple major components are failing at once

• Cooling problems return repeatedly after repairs

Preventive Maintenance

• Clean the condenser coils every 3 to 6 months

• Replace the water filter every 6 months

• Keep air vents clear

• Do not overload the shelves

• Inspect door seals regularly