The situation when there is an ice-cold supply of food in the freezer compartment, and heat in the upper compartment, is familiar to many owners of household appliances. This is not just discomfort, it is a signal that refrigerant circulation or the control system is broken. Modern refrigerators, be it Indesit, Atlant or Samsung, are designed in such a way that the cold is produced by one compressor, but distributed over different zones.
If you are faced with such a problem, do not panic and call a technician immediately. Often the reason lies in trivial things that you can check yourself in a few minutes. However, ignoring the problem can lead to product damage and more expensive repairs.
In this article we will analyze in detail why this happens, which components fail first and how to diagnose a breakdown without having complex equipment at hand. Understanding the principles of operation refrigeration circuit will help you make the right decision on further actions.
The operating principle of single-compressor refrigerators
To understand the essence of the problem, you need to understand how the cold gets into different compartments. The vast majority of modern models use single-compressor system. This means that the motor-compressor pumps freon in a single circle, cooling the evaporator, which is most often hidden behind the back wall of the freezer.
From there the cold air should be distributed into the refrigeration compartment. In models with the system No Frost special air channels and a fan are responsible for this. In drip systems (“crying backdrop”), the cold is transferred through the wall or through a separate circuit. If the compressor is working, but there is no cold in the upper compartment, it means that the path of air or gas movement is disrupted.
It is important to note that the compressor can work in increased mode, trying to cool the sensor in the refrigerator compartment, but due to a freon leak or blockage, the efficiency drops to zero. At this point, the freezer is still holding the temperature due to inertia or residual refrigerant, but soon it will also stop freezing.
⚠️ Attention: If you hear that the compressor is humming, but does not start, or starts for a couple of seconds and clicks, this is a sign of a malfunction of the start relay or the motor itself, and not just problems with distribution cold.
Problems with the No Frost defrosting system
One of the most common reasons why the freezer works but the refrigerator is warm is a malfunction of the automatic defrosting system. In units No Frost frost constantly forms on the evaporator, which must be periodically melted by defrost heating element.
If the defrost timer, thermostat or the heating element itself fails, the evaporator becomes covered with an ice coat. This ice blocks the channels through which the fan is supposed to force cold air into the upper chamber. As a result, the fan hums idle, and there is no circulation.
You can diagnose this problem visually if you remove the back panel in the freezer. You will see a huge lump of ice blocking the fan. In this case, the refrigerator requires complete defrosting (for at least 24 hours with the doors open) and replacing the burnt-out elements of the defrost system.
☑️ Checking the defrost system
Often owners confuse this breakdown with a freon leak, but in the case of clogged ice, the compressor usually works smoothly, without jerking. The main thing is not to try to pick out the ice with a knife, as you can damage aluminum evaporatorwhich will turn a simple repair into complex soldering.
Faults of sensors and thermostat
Electronics controls all processes in modern refrigerator. Temperature is controlled by temperature sensors (thermistors) and thermostats. If the sensor in the refrigerator compartment “lies” and sends a signal to the control module that it is already -5°C, the compressor will not turn on for cooling, although in fact it may be +15°C.
In mechanical models, a thermostat with a capillary tube is responsible for this. If its tube has become dislodged, ruptured, or lost sensitivity, the circuit does not complete. In models with electronic control (LG, Whirlpool), sensors often fail due to voltage surges or natural aging.
How to check the sensor with a multimeter?
To check, you need to remove the sensor and place it in water with ice. The resistance of a working thermistor at 0°C should correspond to the nominal value (usually about 5-10 kOhm, depending on the model). If the resistance is infinite or equal to zero, the sensor is dead.
A symptom of sensor failure is often chaotic operation of the unit: it may not turn on at all or, conversely, work without interruption, freezing everything in the freezer, but not cooling the top. Replacing the sensor is a quick procedure, but requires access to the internal wiring.
Freon leakage and clogged capillary tube
These are more serious technical faults. If a microcrack has formed in the system (often in the foamed part of the housing or at the welding site), the refrigerant gradually evaporates. Freon becomes insufficient to cool the entire volume. Since the freezer is located closer to the exit from the evaporator, it cools first, and the gas reaches the refrigeration chamber warm.
A similar picture is observed when there is a blockage capillary tube. Oil and freon circulate in the system; over time, a paraffin plug may form or moisture may enter, which turns into an ice blockage. The pressure drops, circulation is disrupted.
| Symptom | Freon leak | System clogged |
|---|---|---|
| Compressor operation | Works almost non-stop | Works with overheating, may hum |
| Condenser temperature | Cold or partially warm | Hot before blockage, cold after |
| Dynamics | The problem grows gradually | Can happen suddenly |
| Repair | Search for leaks, soldering, refueling | Blowing, replacing the filter-drier |
It is impossible to eliminate these faults on your own. A vacuum pump, a pressure gauge station and a supply of freon are required. Attempts to “tweak” something with your own hands will only lead to final breakdown of the compressor.
Failure of the blower fan
In systems No Frost the fan is responsible for moving cold air. If it is jammed with ice (due to defrosting problems discussed above) or the motor winding is burned out, air stops flowing into the refrigerator compartment.
You can hear the motor humming, but there is no characteristic wind noise inside. Sometimes the fan will start making a cracking or grinding noise before stopping completely. In some models Beko or Candy when the fan breaks down, a characteristic sound signal is heard.
To check, you need to get to the fan (usually it is behind the back wall of the freezer) and check whether it spins by hand when the power is turned off. If it is tight, the bearing needs lubrication or replacement. If it burns out, just replace the unit.
⚠️ Attention: Do not turn on the refrigerator for a long time with the fan not working. An ice lump will begin to quickly grow in the freezer, which will then be very difficult to remove without damaging the plastic.
Failure of the control module
The most difficult case is a malfunction of the “brain” of the refrigerator. The electronic control module may receive correct data from sensors, but process it incorrectly or not supply voltage to the necessary components (compressor, fan, valves).
This often happens after power surges in the network. Symptoms may be strange: indicators on the panel are blinking, the refrigerator turns on and off randomly, or only the freezer works, ignoring commands to cool the upper chamber.
Diagnostics of the module requires special knowledge in electronics. Often swollen capacitors or traces of burning are visible on the board. Repairing the module is possible, but it is often cheaper and more reliable to replace it with a new or refurbished one.
Frequently asked questions (FAQ)
You can Is it possible to use the refrigerator if the upper chamber does not work?
Short-term - yes, the food will not spoil in a couple of hours. But (long-term use) will lead to damage to the compressor, as it will work for wear, trying to reach a non-existent temperature. In addition, bacteria will begin to multiply in a warm chamber.
How long does it take to defrost the refrigerator when icing occurs?
Minimum 24 hours. Many people turn off the unit at night, but this is not enough. The ice in the channels and on the hidden evaporator melts slowly. Complete defrosting with the doors open is the only safe way to restore the operation of the system. No Frost.
Why did the refrigerator work after defrosting, but after a week it stopped again?
This is a classic sign of a malfunction of the defrosting system. You removed the effect (ice), but not the cause (burnt-out heating element, timer or sensor). Ice will build up again and block the channels. The faulty part needs to be replaced.
Can I add freon myself?
No. To do this, you need to know the type of freon, the exact dosage, and have a vacuum pump to remove moisture and air from the system. Simply “adding gas” from a can means ruining the compressor and completely clogging the system with oil or moisture.
Where to look for a leak if everything is intact on the outside?
Most often, leaks occur in the foamed part of the housing (internal circuit) or at the point where the pipes enter the cabinet. Capacitors located around the perimeter of the door are also often poisoned (to prevent the doors from sweating). Only specialists with a leak detector can find the exact location.