Owners of household appliances often face a situation when LG refrigerator ceases to perform its main function - cooling products. This may happen suddenly or develop gradually as the temperature in the chambers slowly rises and the food begins to spoil. Ignoring a problem in the early stages often leads to more complex and expensive repairs, so it is important to quickly diagnose the source of the problem.
Modern models of the Korean brand are equipped with sophisticated electronics and innovative systems, such as Linear Inverter Compressor, which makes them reliable, but sensitive to voltage changes or violations of operating rules. If your unit works, but does not freeze properly, the reason may be hidden either in a simple blockage or in the failure of expensive components. In this article we will analyze in detail the mechanical, electrical and software causes of failures.
The first thing to do when a problem is detected is to conduct an initial visual diagnosis. Do not rush to call a technician if the device simply does not turn on after a power surge or if you accidentally switched it to the “Vacation” mode. Understanding the basic principles of operation will help you save time and money, and will also give you a clear idea of what exactly happened to your device.
Checking settings and operating modes of electronics
Before opening the technical compartments, you need to make sure that the problem does not lie in a software failure or incorrectly set parameters. The electronic control board may have received a short-term impulse that confused the settings, or the user may have accidentally activated a specific operating mode. Models with a display on the door often display error codes that immediately point to a faulty unit, such as Er FF or dH.
Check to see if the Vacation mode is turned on, which turns off the cooling in the refrigerator compartment to save energy while the freezer continues to operate. It is also worth making sure that the quick freezing function (Express Freeze) is not activated on a permanent basis, which can lead to overloading the system and subsequent failure to protect it. Resetting the settings to factory settings often solves the problem of electronics glitches.
For correct operation of temperature sensors, it is important that they are not covered with food or ice. If the thermostat “sees” an incorrect temperature due to ice build-up, it will not command the compressor to turn on. In some cases, it is necessary to completely defrost the unit within 24 hours to restore the normal defrost cycle.
⚠️ Attention: Before carrying out any manipulations with the electrical part or attempting to reset the settings, be sure to unplug the refrigerator for at least 15-20 minutes. This is necessary to discharge the capacitors and completely restart the control controller.
Mechanical reasons: fan and No Frost system
In systems No Frost cold air circulation is forced using a fan. If this unit fails, becomes jammed, or becomes covered in ice, the cold stops flowing into the chambers, although the compressor may work properly. A characteristic sign of such a malfunction is the absence of noise from a working fan or the appearance of extraneous humming and crackling inside the freezer.
Often the fan is blocked by an ice plug, which is formed due to a malfunction of the defrost system. The heating element of the heater or the defrost sensor may not respond in time, as a result of which the evaporator becomes overgrown with a “fur coat,” the fan blades freeze and the motor burns out or jams. In this case, the refrigerator hums, but there is no cold, since the air channels are blocked by ice.
For diagnostics, you need to remove the back panel in the freezer and visually assess the condition of the evaporator and fan impeller. If ice freezing is significant, complete defrosting will be required. If the fan is free, but does not spin when turned on, check its winding with a multimeter for a break.
Faults of the compressor and start relay
The heart of any refrigerator is the compressor, and LG models often use inverter motors, which are characterized by quiet operation and energy efficiency. However, if the compressor hums but does not start, or starts for a few seconds and immediately turns off with a click, the problem lies in the start protection relay or the motor itself. In inverter models, the electronic unit located directly on the compressor is responsible for starting.
The classic symptom of a malfunction is a hot compressor housing with cold pipelines. This indicates that the refrigerant does not circulate through the system, or the piston group is worn out and does not create the necessary pressure. Also, the cause may be an interturn short circuit of the motor windings, which requires replacement of the entire unit, since repairing the compressor is not economically feasible.
It is important to distinguish between the normal noise of the inverter and an emergency knock. Inverter compressors can operate at different speeds, producing sounds similar to gurgling or rustling. However, if you hear a distinct metallic clanging or strong vibration of the housing, this is a sign of mechanical destruction of the internal components.
Freon leakage and capillary tube blockage
If the compressor runs continuously, trying to gain temperature, but there is no cold or it is very weak, and the condenser (grid at the back) remains only partially cold or warm, it is likely refrigerant leak. Freon can escape through microcracks in the evaporator, often hidden by a foaming agent, or through solder joints. In models with a system Multi Air Flow leakage can occur in the channels connected to the door.
Another common problem is blockage of the capillary tube. This may be caused by moisture entering the system (ice blockage forms) or contamination by oil and metal wear products (technological blockage). In this case, the pressure in the system increases sharply, the compressor operates with overload, but the circulation of freon stops.
It is difficult to diagnose a leak or blockage at home, since special equipment is required: a pressure gauge station, a leak detector and a vacuum pump. Visually, the presence of a leak may be indicated by swelling of the refrigerator wall or the appearance of oily spots at the site of damage to the pipeline.
Diagnostic table of main symptoms
To simplify troubleshooting, use the table below. It will help to compare the observed symptoms with the most likely causes of the breakdown.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| It hums, but does not freeze, it’s warm inside | The fan is faulty or the evaporator is frozen | Defrost 24 hours, check the fan |
| The compressor turns on for 5-10 seconds and clicks | The starting relay or compressor winding is faulty | Replacing the relay, checking the windings |
| Works constantly, there is little cold, it’s warm in the back | Freon leak or clogged capillary system | Call a technician to find the leak and refill |
| The freezer is working, the upper chamber is warm | Air supply channels or damper are clogged | Checking the Air Flow damper, defrosting |
| Error code on the display (for example Er IF) | Failure of a specific sensor or unit | Checking the code with the instructions, replacing the sensor |
Problems with the thermostat and temperature sensors
The electronics of the LG refrigerator rely on the readings of temperature sensors (thermistors). If one of them fails and shows incorrect values (for example, it reports that it is -20°C in the chamber, although it is +10°C), the compressor simply will not turn on. Most often, evaporator sensors or air flow sensors break down.
In older mechanically controlled models, a thermostat with a bellows tube is responsible for turning on the motor. If its capillary tube loses its seal or moves, the refrigerator will stop responding to rising temperatures. In such cases, only replacing the entire assembly helps.
Thermistors are checked by measuring their resistance at different temperatures. The resistance should change smoothly. A sharp jump or lack of response indicates a malfunction of the element. You can replace the sensor yourself by selecting an analogue with similar characteristics.
☑️ Diagnostics before calling a technician
When you need to call a professional technician
Despite the desire to save money, there are situations when the intervention of an unskilled user can lead to final breakdown of the unit. If diagnostics indicate a problem with a sealed circuit (leakage, blockage) or the compressor needs to be replaced, you cannot do without special tools and skills in soldering copper tubes.
Professional help is also necessary if, after self-defrosting and checking the electrical circuits, the problem does not disappear. The technician will use a vacuum pump to remove moisture from the system and charge the exact amount of refrigerant indicated on the nameplate of the specific unit. Violation of the charging technology will lead to rapid failure of the compressor.
In addition, original spare parts for LG, such as inverter boards or specific sensors, often require calibration or have connection features known to service engineers. The use of non-original analogues of low quality can provoke new errors in the operation of electronics.
⚠️ Attention: Working with refrigerants requires a license and special equipment. Personally piercing the tubes or attempting to fill them “by eye” is dangerous to health and can lead to an explosion or fire.
Frequently asked questions (FAQ)
Why does the LG refrigerator freeze only after defrosting?
This is a classic sign of a defrost system malfunction. Most likely, the evaporator heating element has burned out, or the defrost sensor or timer is faulty. Ice builds up on the evaporator, blocks the fan, and the cold stops flowing. After defrosting, the ice melts, the system operates until a plug forms again.
Is it possible to operate the refrigerator if it is tilted?
No, the refrigerator must stand strictly vertically. An inclination of more than 2-3 degrees can lead to improper operation of the compressor (oil will leave the crankcase) and disruption of refrigerant circulation. In addition, the doors may not close tightly, which will lead to freezing.
What does the flashing temperature indicator on the display mean?
A flashing indicator usually indicates that the temperature in the chamber is above the set norm. This may happen immediately after switching on, after loading a large amount of warm food, or if the cooling system is faulty. If the blinking does not stop after several hours of operation, diagnostics are required.
How often do you need to defrost an LG No Frost refrigerator?
The system No Frost does not require regular manual defrosting to remove ice, as this happens automatically. However, it is recommended to completely defrost and wash the refrigerator at least once a year for hygiene and checking the condition of the seals and channels.
Why did the refrigerator begin to work worse after replacing the compressor?
The reason may be poor-quality evacuation of the system (moisture or air remained), the wrong amount of freon charged, or the use of a non-original compressor with unsuitable performance. The filter drier could also become clogged if it was not replaced during repairs.