The situation when the refrigerator continues to hum and the light inside is on, but the food begins to deteriorate, and the temperature in the cells is approaching room temperature, causing panic in any home cook. This is a classic symptom indicating a refrigerant cycle problem or a control system failure. The external serviceability of equipment is often misleading, making you think that the problem is temporary, but in 90% of cases the intervention of a technician or serious diagnostics is required.
There can be many reasons for this behavior: from a banal door sticking to a critical freon leak. It is important to understand that the compressor can run idle, trying to build up pressure that it physically cannot create due to depressurization of the circuit. Ignoring the first signs of a malfunction often leads to engine combustion, which turns a simple repair into an expensive replacement of the unit. modern units there can be many: from a banal door sticking to a critical freon leak. It is important to understand that the compressor can run idle, trying to build up pressure that it physically cannot create due to depressurization of the circuit. Ignoring the first signs of a malfunction often leads to engine burnout, which turns a simple repair into an expensive replacement of the unit.
In this article we will analyze in detail the mechanical and electrical faults that lead to a lack of cold when the engine is running. You will learn how to independently carry out initial diagnostics and in which cases calling a specialist becomes the only solution. If the compressor runs continuously without stopping, but there is no cold, this is almost always a sign of a refrigerant leak or a clogged system.
Problems with tightness and refrigerant leakage
The most common reason why Atlant refrigerator or any other model stops freezing is a banal freon leak. The refrigerant circulates in a closed circuit, and if a microcrack forms in the tubes or evaporator, the gas escapes. At the same time, the compressor continues to hum, trying to pump through the remaining gas, but effective cooling does not occur.
Often a leak occurs in the foamed part of the housing where the evaporator tubes are located. This may be a result of metal corrosion or mechanical damage during transportation. It is difficult to visually notice such a breakdown, since the gas has neither color nor odor. An indirect sign may be swelling of the side walls or the appearance of rusty spots in the lower part of the unit.
If you are faced with a similar situation, you need to check the tightness of the seals. A loosely closed door leads to a constant influx of warm air, and the system does not have time to cool it, although technically the freon may be in place. However, if the door is closed hermetically and there is no cold, most likely you will need to search for the leak using a leak detector and then refuel.
⚠️ Attention: An independent attempt to refuel the refrigerator without eliminating the cause of the leak is useless. Freon will leave again in a few days or weeks, and the compressor may fail due to dry running without proper cooling.
For diagnostics, technicians use a pressure gauge station, connecting it to the service pipe. If the pressure in the system is below normal or absent at all, a leak is confirmed. Repair in this case includes soldering the damaged area, evacuation of the system and charging with new refrigerant strictly by weight.
Faults in the compressor and start relay
The compressor is the heart of the refrigeration unit, creating the necessary pressure for freon circulation. If you hear that the motor hums, clicks, but does not start, or starts for a couple of seconds and stalls, the problem lies in the start protection relay or the motor windings. In some cases, the compressor works, but does not create the required compression due to wear of the valves.
The starting relay is responsible for supplying voltage to the starting winding at the time of start-up. If it burns out, the motor cannot switch from start mode to operating mode. This is often accompanied by a characteristic click and subsequent silence or humming. Replacing a relay is a simple procedure and is often done independently if an exact copy of the part is selected for your model.
A more serious problem is an interturn short circuit in the compressor windings. In this case, the engine may hum, heat up, and even try to turn the shaft, but there is not enough power to compress the gas. You can check the integrity of the windings with a multimeter by ringing the contacts. If the resistance tends to zero or infinity, the compressor must be replaced.
- 🔌 Clicks and silence: most often indicates a malfunction of the starting relay or thermostat.
- 🔥 Strong heating of the case: a sign of engine operation in emergency mode or jamming of the piston group.
- 🔊 Humming without vibration: may indicate that the motor shaft is jammed and it is running idle.
It is important to note that modern inverter compressors operate on a different principle. They do not turn off completely, but change the rotation speed. If the inverter LG refrigerator stops freezing, diagnostics require a special tester to check the control board and the motor itself. A regular test is not enough here.
How to check the start relay?
Carefully remove the plastic casing from the back of the refrigerator. Find the black box (relay) on the side of the compressor. Take it off and shake it near your ear. If you hear a rattling sound (like broken ceramic), the relay is burnt out and needs to be replaced. If the sound is dull, the problem is most likely in the compressor itself or the wiring.
Clogged capillary tube and filtration system
The capillary tube is a thin copper channel connecting the condenser and evaporator. It is here that a sharp drop in refrigerant pressure occurs, which leads to its evaporation and heat absorption. The diameter of the tube is so small that even a microscopic particle of debris left after a poor-quality repair, or a lump of frozen oil can completely block the freon current.
Signs of a blockage are specific: the compressor runs for a very long time and gets very hot, the condenser (grid at the back) can be only partially hot or cold, and the evaporator inside the chamber is not covered with frost. The pressure on the suction side becomes vacuum, and on the discharge side it becomes abnormally high.
Often a blockage occurs in the area of the filter-drier, which stands in front of the capillary tube. This element is designed to trap moisture and dirt. If the system was opened and left open for a long time, the filter could absorb moisture from the air, which, when frozen, turned into an ice plug. Such a plug may appear and disappear, creating the effect of a “floating” malfunction.
| Symptom | Capillary clogged | Freon leak | Thermostat malfunction |
|---|---|---|---|
| Operation compressor | Continuous, overheating | Continuous or cyclic | Shuts off or does not turn on |
| Condenser temperature | Partially hot | Cold or warm | Normal |
| Frost on the evaporator | Absent or at the entrance | Absent | Full or absent |
| Operation sound | Strained humming | Quiet or normal | Silence or clicks |
Removing blockages requires professional equipment. The technician cuts off the filter, purges the system with high pressure nitrogen to push out the plug, and installs a new dryer. After this, vacuuming must be carried out to remove moisture and residual air.
Failures in the operation of sensors and electronics
B modern models with a system No Frost and electronic control monitor the temperature by sensors rather than mechanical thermostats. If the air or evaporator temperature sensor gives incorrect readings, the “brain” of the refrigerator may assume that the cold has already been reached and not turn on the compressor, or, on the contrary, run it for nothing.
Particular attention should be paid to the defrost sensor. In refrigerators with automatic defrost, it controls the heating element. If the sensor is faulty, the evaporator may become overgrown with a “coat” of ice, which will block the air circulation channels. As a result, the fan will circulate warm air, and the food will defrost, although the compressor may work properly.
Electronics diagnostics begin by checking the error codes on the display. Many brands such as Bosch, Electrolux or Samsung, display combinations of symbols when sensors malfunction. For example, flashing lights may indicate an open circuit to the sensor. Checking the resistance of the sensors is carried out with a multimeter at different temperatures.
⚠️ Attention: Electronic control modules are sensitive to voltage surges. If your network frequently experiences fluctuations, it is recommended to use a stabilizer to avoid costly repairs to the control board.
Sometimes the problem lies not in the sensor itself, but in the oxidation of the connector contacts. In conditions of high humidity and vibration, connections may lose contact. Visual inspection of the chips and cleaning the contacts with alcohol often helps restore operation without replacing parts.
The influence of the No Frost mode and the defrost system
No Frost system refrigerators are more complex than usual. Here, the cold is created in a separate evaporator, hidden behind a plastic panel, and distributed by fans. If the refrigerator hums but does not freeze, the air supply duct may have frozen or the fan has failed.
The defrost system consists of a heater (heating element), a timer (or electronic module) and a defrost sensor. If the heating element burns out, the ice on the evaporator does not melt. Over time, the ice lump grows and blocks the fan. The air stops circulating and the chambers become warm. In this case, the compressor can work, trying to cool the evaporator itself, which has already turned into ice.
You can check the defrosting system by completely defrosting the refrigerator. Leave the unit switched off with the doors open for 24 hours. If after turning it on it worked normally, but after 1-2 weeks the problem recurred, it means that the defrosting system is not functioning. It is necessary to check the heating element for breakdown and circuit integrity.
☑️ Primary diagnosis No Frost
It is important to consider that some models use only one heating element, while others use several, including a drip heating element. Failure of any element can upset the balance of the system. It is also worth checking the rubber door seal: if it allows air to pass through, moisture will constantly flow inside and freeze, overloading the defrosting system.
Mechanical damage and external factors
Do not discount physical damage. If the refrigerator has recently been transported without securing the compressor or shipping bolts (if any), the internal tubes may have broken. Also, shocks during rearrangement can damage the condenser grille at the back, which will lead to an instant leak of freon.
The location of the refrigerator also plays a role. If the unit is placed close to a wall or in a niche without clearance for ventilation, heat transfer is disrupted. The compressor overheats and goes into protection without having time to cool the chambers. The minimum distance from the back wall to the wall should be 5-10 cm.
Contaminator contamination with dust and animal hair is another common reason. The dust layer acts as a heat insulator, preventing the freon from cooling. As a result, the pressure in the system increases, the load on the compressor increases, and the cooling efficiency decreases. Regular cleaning of the back of the refrigerator with a vacuum cleaner is a mandatory maintenance procedure.
In conclusion, it is worth noting that diagnosing a refrigerator requires a systematic approach. You should always start with simple things: checking the voltage in the network, how tightly the door is closed and the cleanliness of the capacitor. If these measures do not help, you will most likely need to call a specialist to work with freon and electrical equipment.
Why does the refrigerator freeze in only one compartment?
Most often this indicates a problem with air circulation (in No Frost) or a freon leak. If the freezer is not freezing, there is likely a leak. If the refrigerator compartment does not freeze, the air supply duct may be clogged or the damper regulator is faulty.
Is it possible to operate the refrigerator if it does not freeze?
It is strictly not recommended. The compressor is working hard, trying to achieve non-existent cold, which will lead to its combustion. In addition, bacteria will begin to multiply in the chambers, spoiling the food and creating an unpleasant odor, which is then difficult to remove.
How long should the refrigerator cool down after defrosting?
After complete defrosting (24 hours off) and turning on, the refrigerator should gain temperature within 2-4 hours. If after 6-8 hours of compressor operation the temperature does not decrease, a “fur coat” freezes or an unnatural noise is heard, diagnostics are required.
What to do if, after replacing the freon, the refrigerator still does not freeze?
Perhaps there is moisture or air left in the system that was not removed during vacuuming. The reason may also be poor-quality freon, incorrect dosage, or the presence of a second, hidden blockage. A second call to the technician is required.