The situation when LG refrigerator with the system No Frost stops cooling food in the upper compartment is familiar to many owners of this popular technology. Often this happens suddenly: you open the door, and there the temperature is almost room temperature, while the freezer may continue to work properly or, conversely, also warm up. This behavior of the unit signals a violation of the circulation of cold air, which, according to the engineers, should be evenly distributed throughout the entire volume.
You should not panic right away, since in some cases the problem lies in trivial things that can be fixed without calling a technician. However, ignoring the symptoms can lead to food spoilage and more complex, expensive compressor repairs. Temperature violation in the upper compartment most often indicates a malfunction of the evaporator, defrost system or refrigerant leak.
In this article we will analyze in detail the main causes of the malfunction, from simple ones operational errors to complex technical breakdowns. You will learn how to carry out initial diagnostics, understand when you can try to repair the device yourself, and in which cases it is better not to risk it and contact a service center. Remember that a correct and timely response to a malfunction refrigeration equipment extends its service life.
Primary diagnostics: excluding simple causes
Before disassembling the back wall or calling a technician, it is necessary to conduct a basic check. Users often forget about simple things that block the operation of smart electronics LG refrigerator. For example, if the door of the upper compartment does not fit tightly due to misalignment or contamination of the seal, warm air constantly flows inside. The system No Frost tries to compensate for heat, working hard, but in the end it simply cannot cope with the volume of incoming heat.
The second important point is the operating mode. Check to see if you have accidentally activated the Holiday or Eco mode, which specifically raises the temperature in the refrigerator compartment to save energy. Also make sure that the thermostat is not set to minimum values. In modern models with electronic control, a failure in the settings could occur due to a power surge.
⚠️ Attention: If you notice that the compressor is running continuously without turning off, and the temperature in the upper chamber does not drop, immediately disconnect the device from the network. Leaving the motor idle for a long time can lead to overheating and burnout of the winding, which will make repairs economically unfeasible.
Inspect the interior space. Products should not be placed close to the back wall where the air ducts are located. If the vents are clogged with bags or boxes, cold air cannot physically reach the top of the chamber. Free up space around air ducts and check whether ice is frozen at the outlet of the duct.
Defrost system: heating element, timer and sensors
One of the most common reasons why LG refrigerator stopped freezing at the top is Evaporator defrost system malfunction. In units with No Frost the frost accumulating on the evaporator (which is hidden behind the back wall) must be periodically melted. If this process is disrupted, the ice “coat” grows and blocks the channels through which the fan should drive cold air into the upper chamber.
The key elements of this system are the heating element (heating element), defrost sensor and timer (or electronic control module). If it burns Defrost heating element, the ice does not melt, and after a few days of operation in ice accumulation mode, air circulation stops completely. Visually, this can be manifested by the fact that it is cold in the freezer, but warm on top. The defrost sensor, in turn, tells the control board when to turn on the heating; if it “lies,” the heating either does not turn on or turns on too late.
Diagnostics of these components requires a multimeter and partial disassembly of the rear panel of the freezer. It is necessary to “ring” the heating element for an open circuit. Often the cause is not the breakdown itself, but the oxidation of the contacts at the place where the heater is connected due to constant humidity.
Symptoms of a defrost sensor failure
If the defrost sensor fails, the refrigerator may behave strangely: for example, turn on to defrost every 5 minutes or, conversely, not defrost for weeks. In the first case, you will notice that the food in the freezer is melting, and in the second, the refrigerator will stop freezing in the upper chamber due to an ice jam.
Problems with the evaporator fan
The heart of the system No Frost is a fan that forcibly circulates cold air from the evaporator into cameras. If refrigerator fan stops rotating, the cold remains in the evaporator area (usually in the freezer compartment), and does not enter the upper chamber at all. As a result, the freezer may be frozen, and the refrigerator compartment may be completely defrosted.
There may be several reasons for the fan stopping. The first is mechanical blocking of the blades with ice. This happens if the defrost system is not working correctly and the ice freezes so much that it freezes the engine. The second reason is a failure of the fan electric motor itself or a break in the wires going to it. The third, less obvious reason is a faulty control board that does not supply voltage to the motor.
To check the fan, you often have to remove the back cover in the freezer. When you turn on the refrigerator, you should hear the characteristic noise of the motor or feel the flow of air with your hand, bringing it to the holes. If there is silence and there is no ice, the motor is most likely burned out. If there is ice and it interferes with the blades, there is a problem in the defrost system, which was mentioned above.
☑️ Fan diagnostics
Freon leakage and problems with the compressor
If the defrost system and fan are working properly, but LG refrigerator it still doesn’t freeze, there is a high probability of a refrigerant (freon) leak. Freon is a working fluid that transfers heat. Without enough gas in the refrigerator circuit, there is simply nothing to cool the evaporator. Leaks often occur in places where tubes are soldered, in the foamed part of the body (where the tubes approach the evaporator) or through microcracks in the evaporator itself if it was damaged during defrosting with a knife.
Symptoms of a freon leak are specific: the compressor works almost without interruption, trying to gain temperature, but there is no cold anywhere or it is very weak. The condenser (rear grill or side walls) may be lukewarm or cold even though the motor is hot. Unlike problems with defrosting, here ice may not form on the evaporator at all, or it appears only in the initial section of the tubes.
Repair in the event of a leak requires professional intervention. It is necessary to find the location of the leak (often using a leak detector), solder it, create a vacuum in the system and fill in new freon strictly according to the weight indicated on the nameplate. It is impossible to do this on your own without equipment.
| Symptom | Probable cause | Difficulty of repair | Necessary equipment |
|---|---|---|---|
| Ice on the back wall of the freezer, top warm | Malfunction of the defrost system (heating element, sensor) | Medium | Multimeter, screwdrivers |
| It makes noise, but does not blow, the top is warm | Fan malfunction | Low/Medium | Multimeter, new fan |
| Compressor hums constantly, no cold | Freon leak | High | Vacuumator, pressure gauges, freon |
| The compressor clicks and does not start | Malfunction of the starting relay or motor | Medium | Multimeter, new relay |
Clogged capillary tube
Another technical malfunction that leads to What LG refrigerator the upper chamber does not freeze is a clogged capillary tube. In the narrow channel through which freon moves, an ice plug may form (due to moisture entering the system) or blockage with oil and metal oxidation products. This prevents the normal circulation of the refrigerant.
Signs of a blockage are similar to a leak: the compressor runs for a long time, there is little cold. However, there is a nuance: when clogged, the condenser (the warm grille at the back) often heats up unevenly - it is hot only to a certain point, and then remains cold. Swelling of the side walls of the refrigerator may also be observed.
Removing a blockage is a complex procedure. The technician often has to “push” the system with nitrogen under high pressure, change the filter-drier and refill the circuit. At home, this operation is extremely difficult and dangerous due to the high pressure in the system.
⚠️ Attention: Never try to break through the blockage by piercing the pipes or heating them with an open fire. This can lead to depressurization of the circuit, ignition of the oil, or even explosion of the compressor. Entrust the work of these systems to professionals.
Faults in the electronics and control module
Modern LG refrigerators are stuffed with electronics. The main control module or a separate board is responsible for the distribution of cold, the operation of fans and the activation of heating elements. If a failure occurs in the electronics (the triac that controls the heating element burns out, or the processor fails), commands to defrost or turn on the fan may not be received.
Often, electronics suffer from power surges or high humidity inside the case. Visually, blackening, swollen capacitors, or traces of corrosion may be visible on the board. Diagnostics requires knowledge in electronics and the availability of circuits. Sometimes a complete reset (reboot) of the refrigerator helps: unplug it for 15–20 minutes, then turn it on again. If the error was software, the system can recover.
If after a reboot the situation repeats and you have checked all the mechanical parts (heating element, fan), most likely the problem lies in the “brains” of the device. Replacing the control module is an expensive repair, but often the only solution.
When to call a technician and when to repair it yourself
The decision to repair it yourself should be balanced. If the problem is clogged air ducts, improper installation, or a burnt-out heating element (if you have the skills and tools), you can handle it yourself. Replacing a heating element or fan in LG refrigerator is a task of moderate complexity that requires care when removing the plastic.
However, if diagnostics indicate a freon leak, a clogged capillary system or a compressor malfunction, self-repair is not recommended. For this work you need special tools: a vacuum pump, a pressure gauge station, a leak detector, a burner. In addition, incorrect refilling of freon can completely kill the compressor.
You should also think about calling a specialist if the refrigerator is under warranty. Any intervention in the design (removing seals, disassembling the compressor compartment) automatically voids the manufacturer's warranty. In this case, it is better to contact an authorized service center LG.
Frequently asked questions (FAQ)
Why in the refrigerator LG No Frost is ice freezing on the back wall of the upper chamber?
An accumulation of ice or “fur coat” on the back wall of the refrigerator compartment (not the freezer!) indicates that the moisture from the food does not have time to evaporate or the condensate drainage system is clogged. This should not happen in the No Frost system. Most often, the problem is a loose door fit or a malfunction of the damper that regulates the flow of cold air.
How long does it take to defrost an LG refrigerator to remove the ice plug?
To completely defrost the No Frost system, so that all the ice in the hidden channels of the evaporator melts, the refrigerator must be turned off with the doors open at least 24 hours. The standard 8–10 hours may not be enough, since ice in hard-to-reach places melts slowly.
Is it possible to use a refrigerator if it does not freeze the top, but the bottom works?
For a short time, it is possible, but you cannot store perishable foods in the upper chamber. Long-term operation in this mode is dangerous for the compressor, which will work at its limit, trying to compensate for the lack of cold. This will lead to rapid wear of the motor.
What does the flashing temperature indicator on the LG panel mean?
A flashing indicator usually indicates that the temperature inside the chambers is higher than the established norm. This can happen either immediately after switching on or during a malfunction. If the blinking does not stop after several hours of operation, this is an error code that requires diagnosis.