The situation when the refrigerator suddenly stops cooling food in the main compartment, while the freezer continues to operate normally, is one of the most common and alarming for owners of household appliances. You open the door, expecting pleasant coolness, but instead you are greeted by stale air at room temperature, while the freezer is still hard ice. Such desynchronized behavior of the unit indicates a violation of the refrigerant circulation or a failure in the control system, but does not always mean a fatal breakdown of the compressor.
The first thing to do at this moment is not to panic and carry out an initial diagnosis to rule out simple causes, such as a clogged drain hole or an incorrectly set thermostat. Often the problem lies in simple freezing of the evaporator, which blocks the flow of cold air into the upper section, or in the sticking of the damper that regulates the flow. Understanding the operating principle of your model, be it classic Drop Cooling or modern No Frostwill help you quickly determine the vector of further actions.
In this article we will analyze in detail the mechanics of the occurrence of such malfunctions, consider typical failure scenarios for various brands and offer a step-by-step algorithm of actions. Timely response changes in temperature conditions can save not only your products, but also the compressor itself from overload, which will inevitably occur when trying to compensate for the cold leak.
Fundamental differences in the operation of cooling systems
To understand why one part of the refrigerator works and the other does not, you need to briefly touch on the design of the system. In classic two-chamber models with one compressor, the refrigerant first passes through the evaporator of the freezer, where it boils and takes away heat, and then, in a less cold state, enters the circuit of the main compartment. If the upper chamber does not freeze, this often means that freon either does not reach it due to blockage, or the control system mistakenly believes that the temperature there has already been reached.
In systems No Frost the situation looks different: here cold air is forced by a fan from the freezer into the refrigerator compartment through special channels. If the fan stops or the air ducts freeze, the cold simply stops flowing upward, although the temperature in the freezer itself, where the evaporator is located, remains low. In such models, the defrosting system becomes a critical element, failure of which leads to rapid accumulation of ice on the fan and ducts.
⚠️ Attention: An attempt to continue operating the refrigerator with the upper chamber inoperative for several days can lead to food spoilage and increased load on the compressor, which will work without interruption, trying to achieve the set parameters.
Modern models often equipped with sophisticated electronics that control dampers and fans based on sensor readings. If one of the temperature sensors in the upper chamber fails and shows incorrect data (for example, that it is -10°C, although in fact it is +15°C), the controller simply will not give the command to supply cold. That is why diagnostics of electronics is often the first step in repairing complex units.
Primary diagnosis: simple causes and their elimination
Before calling a technician or disassembling the back panel, it is worth eliminating factors that do not require intervention in the technical part unit. Often the reason is trivial: food tightly packed the back wall, blocking the exit of cold air, or the door was not closed tightly, which led to abundant snow formation. Check to see if the rubber seal has moved or is cracked, allowing warm, moist air to enter the chamber.
The second important step is to check the temperature conditions. Perhaps someone in the household accidentally moved the thermostat control to the minimum position or activated the “Vacation” mode, which turns off the cooling of the main chamber to save energy. In models with electronic control, it is worth checking whether the error indicator or defrost symbol is lit on the display. Resetting the settings to factory values via the menu or the Reset button sometimes helps restore the correct operation of the controller.
It is also worth listening to the operation of the unit. If the compressor hums continuously without turning off, but there is no cold, this may indicate a freon leak or a problem with the valve. If the compressor turns on rarely and runs in short cycles, it may be the thermostat. For an accurate check, you can use an external thermometer, placing it in the center of the chamber for several hours.
☑️ Primary checklist
No Frost system: problems with defrosting and fan
If your refrigerator is a type No Frost, then the most likely reason for the lack of cold in the upper chamber when the freezer is running is a malfunction of the defrost system. The evaporator, located behind the plastic panel in the freezer compartment, accumulates ice over time. In normal mode, this ice is periodically melted by special heaters (heating elements), and the water flows into the drain pan. If the heating element is burned out, the defrost timer is jammed or the defrost sensor is faulty, ice accumulates and tightly blocks the fan.
As a result, the fan either stops spinning completely or spins, but the air cannot pass through the ice plug into the channels of the refrigerator compartment. You may hear the fan humming or crackling as it tries to get through, but there will be no cold. In some cases, ice blocks not only the fan, but also the air channel itself going to the upper section. This is a classic situation when the freezer is freezing (there is a source of cold), and there is heat in the refrigerator.
To fix the problem, it is often necessary to completely defrost the refrigerator in the off state during the day. This will allow the ice to melt naturally. If, after turning on the unit, cold appeared, but after a week or two the situation repeated itself, it means that elements of the defrosting system need to be replaced: heating element, sensor or timer. Replacing these parts yourself requires access to the evaporator and skills in working with a multimeter.
How to check a defrost heating element with a multimeter?
To check, you need to remove the back panel in the freezer, find the heating element (usually a curved tube under the evaporator) and ring it with the probes of the multimeter in resistance measurement mode. If the resistance is infinitely high (open), the heating element is faulty and requires replacement. Normal resistance is usually from 200 to 500 Ohms.
Single-compressor models: freon leak and capillary blockage
In refrigerators where one compressor serves both chambers, the refrigerant moves sequentially. It first cools the freezer and then passes through the refrigerator circuit. If a micro-leak of freon occurs, its quantity may be enough to create a low temperature in the first circuit (freezer), but the pressure is no longer enough to cool the second circuit (upper chamber). In such cases, the compressor may run continuously, trying to gain temperature, but the top will remain warm.
Another option is a clogged capillary tube. The freon circulation system has very thin tubes that can become clogged with oil oxidation products or moisture (formation of ice blockage). If the blockage occurs after entering the freezer evaporator, then the freezer will work, but the refrigerator will not. It is difficult to distinguish a leak from a blockage at home, but when there is a blockage, you can often hear a characteristic gurgling or whistling sound in the area of the filter-drier.
Repair in both cases requires the intervention of a specialist with equipment for vacuuming the system and charging with freon. It is impossible to fix a leak or clean the capillary yourself without a special tool. It is also important to note that prolonged operation of the compressor when freon leaks leads to its overheating and eventual combustion, so there is no point in delaying repairs.
| Symptom | Probable cause | Nature of compressor operation | Necessary actions |
|---|---|---|---|
| The freezer is freezing, the top is warm, there is no ice | Freon leakage | Works continuously | Call a technician, search for leaks, refill |
| There is a coat of ice in the freezer, the fan does not makes noise | Malfunction of the defrost system | Works cyclically | Defrosting 24 hours, replacing the heating element/timer |
| There is cold, but weak, there is ice on the back wall | The thermostat is faulty | Rare starts | Replacing the thermostat or sensor |
| Gurgling is heard, the cold disappears periodically | Clogged capillary tube | Works with overload | Purge the system, replace the filter |
Faulty damper and air distribution
In many modern models, especially with a system Total No Frost, between the freezer and refrigerator compartments special damper (damper). It opens and closes at the command of the electronics, letting in the right amount of cold air. If the damper mechanism is stuck in the closed position or the drive motor is burned out, cold air physically cannot enter the upper compartment.
You can check the operation of the damper by opening the door of the refrigerator compartment and listening: at the moment of opening or when changing the temperature settings, you should hear a slight click or the sound of the motor operating. In some models, the damper is controlled mechanically by a cable from the temperature regulator, and the problem may be a broken cable or a lever jumping off.
If the damper does not open, the food in the upper chamber begins to deteriorate, despite a working freezer. The problem can be temporarily solved by forcibly opening the damper slightly (if the design allows) or increasing the power of the freezer, but this will lead to freezing of food in the lower chamber. Critical important Do not seal or fix the damper in the open position forever without control, as this will upset the temperature balance and can lead to the formation of condensation and mold.
When professional repairs are needed
There are a number of situations when attempts at self-repair can only harm the equipment or be simply useless. If after a complete defrost (more than 24 hours) the problem does not disappear and you are convinced that the fan is spinning and the damper is opening, most likely there is a hidden refrigerant leak or a serious blockage in the system. These defects require the use of professional equipment: leak detectors, vacuum pumps and manifolds.
Also, you should not interfere with the operation of electronics yourself if you do not have the skills to read electrical circuits. An attempt to “resolder” the sensor or bypass the protection can lead to a short circuit and failure of the main control module, the cost of which is a significant part of the price of the refrigerator. In addition, opening a sealed circuit automatically deprives you of the right to warranty service.
⚠️ Attention: If you smell burnt wiring or see sparking in the area of the compressor or control board, immediately unplug the refrigerator and contact a service center. The operation of such a device is a fire hazard.
A professional technician will conduct diagnostics using the devices, pinpoint the location of the leak or breakage of the unit, and carry out repairs in compliance with the technology. It is often cheaper and faster to call a specialist right away than to buy spare parts by trial and error, which may not fit your model Bosch, LG or Indesit.
Prevention and proper care of equipment
To avoid repeating the situation with the failure of the upper chamber, it is important to follow the operating rules. Regularly, at least once every six months, completely defrost the refrigerator, even if it is equipped with a system No Frost. This will help prevent stubborn ice from accumulating in hidden cavities and extend the life of the defrost system. Also keep the drainage hole in the back of the refrigerator clean - it can be cleaned with a special soft brush or cotton swab.
Do not put hot foods in the refrigerator and try not to keep the door open longer than necessary. Excess moisture entering the chamber settles on the evaporator and turns into ice, which sooner or later will disrupt air circulation. Check the condition of the seals: if they do not fit tightly, the compressor will wear out, and ice will form in the chamber.
Compliance with the temperature regime and periodic checks of the operation of the unit will help you notice deviations at an early stage. If you notice that the refrigerator begins to work louder, does not turn off longer, or the upper chamber has become warmer than usual, do not wait for a complete breakdown, but carry out diagnostics immediately.
Is it possible to temporarily use the refrigerator if the upper chamber does not work?
You can use the refrigerator in this mode only for a short time (1-2 days) for storing products that do not require strict temperature regime, or freezer. However, the compressor will work overload, trying to cool the volume, which can lead to its combustion. In addition, the food in the upper chamber will quickly deteriorate.
Why did the refrigerator work after defrosting, but after a week it stopped again?
This is a sure sign of a malfunction of the automatic defrosting system. The ice melted during manual defrosting and the cold started, but since the heating element, timer or sensor did not work, the ice accumulated again within a week and blocked the system again. The faulty element needs to be replaced.
How long does it take to defrost the refrigerator for diagnostics?
To be completely sure that all the ice in the hidden channels and on the evaporator has melted, the refrigerator should be turned off with the doors open for at least 24 hours. A shorter defrosting may not eliminate ice jams in hard-to-reach places.
Does the amount of food in the refrigerator affect cooling?
Yes, it does. If there is too little food, cold air is not retained and quickly evaporates when opened. If there are too many products and they block the back wall and channels, circulation is disrupted. It is optimal to fill the chamber by 60-70%, leaving gaps at the walls.
What to do if, on the contrary, everything freezes in the upper chamber?
If everything freezes in the fridge compartment, but the freezer is working normally, this indicates a malfunction of the thermostat (does not turn off the compressor) or that the valve is stuck in the open position. In this case, adjustment or replacement of the thermostat/damper is required.