Situation when refrigerator compartment stops cooling food, while freezer compartment continues to operate normally, is one of the most common and at the same time confusing problems in the operation of household appliances. The owner is often perplexed: the compressor is humming, there is ice inside the freezer, but it’s warm on the top shelf, and the milk turns sour in a matter of hours. This behavior of the unit indicates specific malfunctions in the refrigerant circulation system or malfunctions in the automatic defrosting system.
Unlike a complete equipment failure, when the compressor is silent or does not start at all, a partial loss of refrigeration capacity requires a more in-depth diagnosis. Often the problem lies not in a breakdown of the engine, but in a violation of heat exchange or blockage of channels. Understanding the physical processes occurring inside the case will help you quickly determine whether the malfunction can be fixed yourself or a call to a repairman is inevitable.
Modern models, be it Indesit, Atlant or Bosch, use different principles of cold supply, but their operating logic is similar. If you notice that the temperature in the main compartment has risen above +7...+8 degrees, do not panic. The first step is to analyze the accompanying symptoms: is there ice on the back wall, is the fan working, and how long ago was the defrosting carried out.
Principles of operation of the No Frost and static cooling system
To understand why a temperature imbalance occurs, you need to briefly consider the design of your unit. In systems No Frost the cold is produced by an evaporator, which is usually hidden behind a plastic panel in the freezer or in a partition between compartments. A special fan forces cold air through channels into the refrigerator compartment. If this air flow is blocked, the cold simply does not reach the upper shelves.
In models with drip system (crying wall), the evaporator is located directly in the refrigerator compartment, on the back wall. Here the cold is distributed through natural convection and contact with the cooled rear panel. If the compressor is working, but the wall is not frozen or, conversely, is covered with a thick layer of ice that does not melt, this indicates problems with thermoregulation or refrigerant.
⚠️ Attention: In No Frost systems, the main flow of cold comes from the freezer. If everything is frozen there, but it’s warm above, look for a problem in the air supply channels or fan, and not in the amount of food.
The key element in both cases is circulation. In the first case it is forced (fan), in the second it is natural. Violation of any of these processes leads to the described problem. It is also important to note that modern inverter compressors can operate at low speeds, creating the illusion of normal operation, although there may not be enough real power to pump freon throughout the entire circuit.
Malfunctions of the defrost system (Defrost timer and heating element)
One of the most common The reason why the refrigerator does not freezeis a failure in the automatic defrosting system. In No Frost units, frost constantly forms on the evaporator from the moisture contained in the products. Periodically, this ice must thaw. A chain of elements is responsible for this process: a timer (or electronic module), a heating element (TEN) and a defrost sensor.
If the heating element burns out or the timer gets stuck in the “cooling” mode, the ice is on the evaporator does not melt, but grows layer by layer. Sooner or later, this ice ball completely blocks the channels through which the fan should blow cold into the refrigerator compartment. As a result, the freezer still freezes (since the evaporator is there), but cold air physically cannot get into the upper compartment.
You can diagnose this problem visually if you remove the back panel in the freezer. You will see a massive piece of ice blocking the area around the fan and ducts. In such cases, the equipment often makes extraneous sounds: a hum, crackling or whistling, as the fan blades begin to touch the ice.
☑️ Symptoms of defrosting failure
To eliminate the malfunction, you need to replace the burnt heating element or timer. Sometimes the problem lies in the defrost sensor, which “does not sense” that the ice has already melted and prematurely turns off the heating, or, conversely, does not allow it to turn on. Repairing this group of faults is considered of medium complexity and requires skills in working with a multimeter.
Refrigerant leakage and problems with the compressor
The second most common reason is freon leak. The refrigerant circulates in a closed loop, taking heat from the chambers and releasing it to the environment through the condenser (black radiator at the back). If a microcrack appears in the system (often in the foamed part of the body or in soldering areas), the gas gradually escapes.
Why does the freezer still work if there is a leak? The fact is that the freezer evaporator is located at the beginning of the circulation circuit. Freon, even in reduced quantities, manages to cool the first section of the system, but its pressure and volume are no longer enough to go through the entire circle and cool the refrigeration compartment. Over time, when the leak becomes critical, the freezer will stop freezing.
Another option is compressor malfunction. The motor may hum, but not develop the required pressure. This is called “the compressor does not pump.” Valves inside the engine may be worn out, causing freon to not circulate at the correct rate. In this case, the condenser (grid at the back) will be barely warm or cold, although the motor itself is hot.
| Symptom | Probable cause | Characteristic symptom |
|---|---|---|
| The condenser is only partially hot | Freon leakage | The refrigerator runs non-stop |
| The compressor is hot, hums, but does not start | Motor jammed | A relay click is heard after a few seconds |
| The evaporator is covered with an uneven layer of frost | Lack of freon | Frost only at the beginning of the tubes |
| The temperature in the chambers is the same (room) | Complete leak / Compressor failure | The unit is silent or hums in vain |
Eliminating leaks requires professional intervention: finding the location of the damage, soldering, evacuating the system and filling with new gas. It is impossible to carry out these operations independently without special equipment (vacuum pump, pressure gauge station, scales).
Clogged capillary tube
Between the condenser and the evaporator there is capillary tube a very thin copper channel that creates the necessary pressure for freon to boil. The diameter of this channel is a fraction of a millimeter. If there is moisture, dirt or oil breakdown products in the system, a blockage may form in this narrow place.
When clogged, freon cannot circulate freely. The pressure rises before the blockage and then drops after it. Visually, this can manifest itself as follows: the condenser is hot, the compressor is running, but there is no cold anywhere, or the freezer cools poorly, but the refrigerator compartment does not cool at all. Sometimes frost may appear on the section of the tube before entering the evaporator or, conversely, this section remains warm.
Is it possible to break through the blockage yourself?
There is a “folk” method of pumping the system with nitrogen under high pressure, but at home this is extremely dangerous and ineffective. Without a vacuum dehumidifier and filter drier, you will drive moisture deeper into the system, which will lead to the formation of an ice plug and failure of the compressor in a short time.
Often the blockage is accompanied by the formation of an ice plug if there is moisture in the system. Water freezes at the narrowest point of the capillary and blocks the freon flow. Once defrosted, the refrigerator may run for several hours or days until the moisture freezes again. This is a classic symptom of a “floating” malfunction.
Repair in this case involves cleaning the capillary system, replacing the filter-drier and charging with refrigerant. This is a labor-intensive procedure that requires disassembling the heat exchanger and using a professional tool.
Problems with the thermostat and sensors
A (thermostat) or an electronic temperature sensor is responsible for maintaining the set temperature. If this element fails, it can send an incorrect signal to the compressor. For example, “inform” the control module that the chamber is already -5 degrees, although in reality it is +15. thermostat (thermostat) or electronic temperature sensor. If this element fails, it can send an incorrect signal to the compressor. For example, “inform” the control module that the chamber is already -5 degrees, although in reality it is +15.
As a result, the compressor either does not turn on at all, or works for too short periods of time, without having time to freeze the chamber. In electronically controlled models, the sensor may fail. defrost. If it shows an incorrect temperature, the control module may “think” that a defrost process is in progress and not turn on the compressor or fan.
Diagnostics of a mechanical-type thermostat is simple: its contacts can be closed directly. If the refrigerator is working, the thermostat needs to be replaced. It is more difficult with electronic sensors: their resistance changes depending on the temperature, and you need to check them with a multimeter, comparing the readings with the table for a specific model.
Violation tightness and thermal insulation
Do not forget about banal things. If sealing rubber band the door of the refrigeration chamber is worn out, dirty, or the door is warped, warm air from the room constantly enters the chamber. The compressor tries to compensate for heat loss and works without interruption, but due to the constant flow of heat, the temperature does not drop to normal.
Warm air enters the freezer less often, since cold air is heavier and “settles” at the bottom, and the freezer door is usually more airtight. Therefore, a temperature imbalance can be caused precisely by a loose fit of the upper compartment door.
You can check the tightness in a simple way: hold a sheet of paper with the door. If it is removed without effort or falls out easily, the seal requires replacement or adjustment. Also check if anything is preventing the tight closure: a piece of product on the shelf, crumbs or displaced dishes.
⚠️ Attention: Frequently opening the door or leaving it ajar for a long time leads to intense ice formation in the No Frost system, which will eventually also block the cooling channels.
Self-controlled algorithm diagnostics
Before calling a technician, try to perform initial diagnostics. This will help you more accurately describe the problem to a specialist and, perhaps, save money if the problem is a simple defrosting.
- Listen to the operation of the unit. Is the compressor humming? Is the fan working (can you hear air noise)?
- Feel the condenser (grid at the back). It should be warm or hot. If it is cold while the engine is running, there is likely a leak or a problem with the compressor.
- Check the temperature at different points. If the freezer is freezing and the refrigerator compartment is warm, there is a circulation problem (fan, clogged ducts).
- Inspect the back wall in the refrigerator compartment. If there is no frost, but there is no cold either, the compressor or thermostat may not be working. If there is a “fur coat” there, there is a problem with defrosting.
Frequently asked questions (FAQ)
Is it possible to operate a refrigerator if it does not freeze in the upper compartment?
For a short time - yes, if the compressor does not work non-stop. However, if the motor hums continuously, trying to compensate for the lack of cold, this will lead to overheating and burning of the windings. It is better to turn off the device until the malfunction is eliminated.
Why did the refrigerator work after defrosting, but after a couple of days it stopped again?
This is a classic sign of a malfunction of the defrost system (No Frost). The ice melted, the channels became free, and the cold set in. But since the heating element or timer is not working, ice has accumulated again and blocked the air passages. Replacement of parts of the defrost system is required.
How much does the repair cost if refilling with freon is needed?
The cost depends on the volume of gas and the complexity of the work (searching for leaks, soldering). This is usually a mid-priced repair. However, if the leak occurred in the foamed part of the case (inside the wall), repairs may not be economically feasible.
Does the amount of food in the refrigerator affect cooling?
Yes, but indirectly. An empty refrigerator loses cold faster when the door is opened. However, if the products are filled to capacity and block the ventilation openings (especially in No Frost), air circulation is disrupted and some areas may become warm.
Does it need to be replaced if the compressor hums but does not pump?
Yes, if it is diagnosed that the valves inside the engine are worn out or an inter-turn short circuit has occurred, The compressor needs to be replaced. It is impossible to restore its functionality at home.