The situation when the refrigerator LG continues to work, the light in the chamber is on, but the food in the freezer begins to melt, causes panic in any home cook. Most often, owners of two-chamber models with a system No Frost face the fact that the cold ceases to be produced evenly or disappears completely in the lower compartment. This does not always mean a fatal breakdown of the unit; often the problem lies in disruption of defrosting cycles or electronic failures.
Modern refrigerators LG are complex technical devices where a combination of a compressor, refrigerant and air flow control system is responsible for cooling. If freezer stopped freezing, the system could go into emergency mode or the drainage system could simply become dirty. Understanding the principle of operation will help you avoid unnecessary expenses on calling a technician to diagnose basic things.
In this article we will analyze in detail the mechanical and electrical causes of malfunctions that are specific to the Korean assembly. You will learn how to independently check the main components and determine whether professional intervention is required or simple cleaning is sufficient. Diagnostics starts with analyzing the behavior of the compressor and checking the temperature in different zones of the chamber.
The principle of operation of the No Frost system and air circulation
To understand, why the cold disappeared, you need to know how it is created. Unlike older models with a weeping wall, in refrigerators LG with technology No Frost the evaporator is hidden behind the back panel of the freezer. The fan drives cold air through special channels, distributing it throughout the entire volume, and then returns it back to the evaporator for re-cooling.
If this cycle is broken, the cold stops flowing into the chamber. The main elements here are evaporator, a blower fan and an air supply damper. Any failure of one of these components will cause the freezer to become warm, even if the compressor is humming continuously. Ice builds up on the hidden evaporator, blocking the air passage.
⚠️ Attention: If you hear the fan making noise or crackling, but you cannot feel any air coming out of the holes, the fan blades may be blocked by frozen ice. Operating in this mode can burn out the fan motor.
It is important to note that in two-chamber models, cold often enters the refrigerator compartment from the freezer compartment through a special channel. Therefore, a breakdown in the freezer inevitably leads to an increase in temperature in the upper compartment. The system circulation requires free space for the passage of air masses.
Why is it warm in the freezer, but there is ice on the back wall?
This is a classic sign that the evaporator is covered with a “fur coat”. Air cannot pass through the ice layer to the food. Complete defrosting is required within 24 hours to test the hypothesis.
Problems with the evaporator defrost system
The most common reason why it stops freezing LGlies in a malfunction of the defrost system. Periodically, usually every 8-12 hours, the refrigerator must stop the compressor and turn it on to melt the frost on the evaporator. If this process does not occur, ice accumulates until it completely blocks the air channel. Defrost heating elementto melt the frost on the evaporator. If this process does not occur, ice accumulates until it completely blocks the air channel.
Several critical elements are involved in the defrost chain: a heating element (heating element), a defrost sensor and a timer (or electronic control module). Failure of any of them stops the defrosting cycle. Visually, this is manifested by the fact that the refrigerator is constantly running, but there is no cold, and a block of ice is hidden behind the back wall of the freezer.
☑️ Symptoms of defrosting failure
Often the culprit is defrost sensor, which should record the temperature of the evaporator and give the command to turn on the heating element. If it “lies” or is open, the control module “thinks” that there is nothing to defrost and does not supply voltage to the heater. This leads to fouling of the radiator and cooling stops.
A multimeter is required to check the heating element and sensors. By ringing the circuit, you can identify a break. However, it is worth remembering that in models LG with a linear compressor, diagnostics can be complicated by the presence of additional electronics. Heating element rarely burns out completely, more often its contact with the terminals is broken due to corrosion.
Faults of the compressor and start relay
The compressor is the heart of the refrigerator LG. If it doesn't start or idles, there will be no cooling anywhere. Modern models often use inversion or linear compressors, which are sensitive to voltage surges. If you hear a click, a hum for a few seconds, and then a click again, this is a sign of a startup attempt that fails.
The cause of such symptoms is often starting relay or a capacitor. These are small parts that help the engine gain momentum. If the relay is stuck open or the winding is burned out, the compressor will not be able to start. In older models, the relay can be replaced independently, in new ones with inverters the situation is more complicated.
Another terrible but possible reason is turn-to-turn short circuit the compressor windings. In this case, the motor may hum, but not create the necessary pressure in the system. You can check this by measuring the current consumption: if it is significantly higher than the rated current, but there is no cold, the compressor is most likely faulty.
It is important to distinguish between noise and knocking. Linear compressors LG can make specific sounds during operation, but they should not be accompanied by vibration of the housing or lack of cold. Freon pressure also depends on the proper operation of the motor.
Refrigerant leakage and blockage capillary tube
If the compressor runs smoothly, without overheating and unnecessary sounds, the fan turns, the defrosting system is working, but cold is not generated, perhaps there is no freonin the system. Leakage can occur due to corrosion of tubes (especially in the foamed part of the body) or mechanical damage during transportation.
The symptoms of a leak are specific: the condenser (grid at the back) remains cold or warm only partially, and not hot over the entire area. In the freezer, ice may form only in the corner or at the entrance, but not throughout the entire volume. Over time, the temperature equalizes room temperature.
Clogged capillary tube is the second reason for the lack of refrigerant circulation. An ice or mud plug forms in the system, which prevents freon from passing from liquid to gaseous state in the right place. In this case, the compressor may operate with overload, trying to push through the system.
| Symptom | Probable cause | Nature of compressor operation |
|---|---|---|
| Cold condenser | Freon leak | Works constantly or on a timer |
| Condenser is hot at the outlet | System clogged | Works with overload, may turn off |
| Frost only at the entrance | Lack of freon | Works as usual |
| Ice on the entire tube | Moisture in the system | Cyclic operation with interruptions |
It is impossible to eliminate a leak or blockage on your own. You need to call a specialist with equipment for vacuuming the system, filling refrigerant and sealing the tubes. Attempts to simply add freon without eliminating the cause of the leak will give a temporary effect for several days.
Failures in the operation of the electronic control module
In two-chamber refrigerators LG with a system No Frost the electronic control module is responsible for all processes control unit. It reads readings from temperature sensors and makes a decision to turn on the compressor, fan or heating element. If the “brains” of the refrigerator are faulty, the unit may behave unpredictably.
A common problem is power surges in the network, which damage board elements or disrupt the program. In this case, the refrigerator may not respond to commands, show an error on the display (if there is one), or simply not turn on cooling. Sometimes a reboot helps: disconnecting from the network for 15-20 minutes.
If after defrosting and checking the contacts the problem returns, the contacts on the board connectors may have oxidized or the compressor control triac has burned out. Electronic module requires professional diagnostics with an oscilloscope.
⚠️ Warning: Do not attempt to repair the control board yourself unless you have experience working with high voltage electronics. Unqualified repairs can lead to complete failure of the compressor.
It is also worth checking the temperature sensor in the chamber itself. If it shows incorrect data (for example, that it is -30°C in the chamber, although it is +5°C), the control module simply will not turn on the cooling, believing that the norm has already been reached. This is a common reason why LG does not freeze.
Mechanical damage and operating errors
Sometimes the reason is trivial and lies in improper use. If you pack the freezer too tightly with food, blocking the air circulation holes, the cold simply cannot be distributed. In the system No Frost free air flow is critical.
It is also worth checking the rubber seals on the door. If they are worn out, dirty or the door is warped, warm air constantly enters the chamber. The compressor works hard, trying to compensate for heat loss, but at some point it stops coping, and the temperature rises.
We must not forget about the position of the refrigerator. If it is too close to the wall or heating devices, heat transfer is disrupted. The instruction LG requires maintaining clearances for ventilation of the compressor compartment and the rear wall.
Another factor is installing the refrigerator in an unheated room. Although many models are stated to operate at low temperatures, the oil in the compressor may thicken and the sensors may not work correctly, which will lead to the system stopping.
Self-diagnosis algorithm
Before calling a technician, try going through the diagnostic path yourself. This will help you more accurately describe the problem to a specialist or even solve it yourself. Start by completely unplugging the refrigerator.
Leave the unit to defrost for at least 24 hours. The doors must be open. This is necessary so that all the ice that has accumulated on the hidden evaporator melts and the water leaves through the drainage. If, after turning on, the refrigerator works normally for several days, and then stops freezing again, the problem is definitely in the defrosting system (heating element, sensor, timer).
If defrosting did not help, listen to the operation of the compressor and check the heating of the condenser. This will narrow your search down to a mechanical part or leak. Remember that complete defrosting during the day eliminates up to 40% of cooling problems in No Frost refrigerators.
Why did the refrigerator work after defrosting, but after a week it stopped again?
This is a 100% sign of a malfunction of the defrosting system. Ice has again accumulated on the evaporator and is cutting off the air. It is necessary to change the heating element, defrost sensor or check their power supply circuit.
Is it possible to operate a refrigerator with a non-working freezer?
It is highly not recommended. The compressor will run non-stop, trying to build up temperature, which will cause it to overheat and burn out. In addition, the food in the refrigerator compartment will also begin to deteriorate.
How long should the compressor cool down before turning it on again?
After any shutdown, especially after defrosting, let the compressor stand off for at least 2-4 hours. The oil must drain into the crankcase, otherwise water hammer and valve damage may occur.
What does the flashing indicator on the LG panel mean?
Flashing indicators usually indicate a malfunction. The number of flashes or combination of lights indicates a specific component (for example, sensor or fan error). You should look for the exact decoding in the instructions for your model.