The situation when food in the refrigerator compartment remains fresh, but supplies in the freezer begin to melt, causes panic in any home cook. This is a classic symptom indicating poor refrigerant circulation or a malfunction in the temperature control system. Modern units, be it Indesit, LG or Beko, are designed so that the cold is generated in one place and distributed among different chambers.
Understanding how exactly your device works will help you quickly identify the cause of the malfunction. If the compressor is humming, but there is no cold, or the motor is silent, the algorithms for finding the problem will be radically different. In most cases, the problem lies in a freon leak, a clogged capillary tube, or a failure of one of the sensors.
You should not immediately call a technician if you have not checked the basic things. Sometimes the problem is solved in five minutes of defrosting, and sometimes serious repairs are required by replacing the compressor. Below we will analyze in detail the mechanics of the process and the main breakdowns that lead to the described temperature imbalance.
Principle of operation: where does the cold come from
To understand why one chamber works and the other does not, you need to understand the physics of the process. In most household models, especially those equipped with the No Frostsystem, the evaporator is located hidden, usually behind the rear wall of the freezer compartment. It is there that freon boils, taking heat from the internal volume.
The air is cooled at the evaporator and, using a fan, is forced into the fridge compartment through special channels. If the control system is working properly, it regulates the dampers, supplying the right amount of cold air. In models with one compressor and one cooling circuit, the freezer is always the primary source of cold.
⚠️ Attention: In two-compressor models, each chamber has its own independent circuit. If you have just such a refrigerator, then a breakdown of the freezer should not affect the operation of the refrigerator compartment, since these are actually two different devices in one housing.
The system is controlled by an electronic module or a mechanical thermostat. Sensors constantly read the temperature at different points. If the sensor in the freezer “lies” and shows that it is -20°C, although in fact it is -5°C, the compressor may turn off and the food will begin to spoil.
Refrigerant leak: the most common cause
One of the most likely reasons for the situation when freezer compartment stops freezing is simple freon leak. The refrigerant circulates in a closed circuit, but over time the metal of the tubes may corrode, or a microcrack may occur at the soldering site. Also, leaks often occur in the foamed part of the housing, where the defrost circuit or evaporator passes.
If there is a shortage of freon, its pressure is not enough to cool the entire volume of the evaporator. As a result, cold manages to be created only at the beginning of the circuit (often this is the area of the refrigerator compartment or the upper part of the freezer), and the refrigerant simply does not reach the bottom of the freezer compartment in the required state. In this case, the compressor can work continuously, trying to increase the temperature, but to no avail.
It is difficult to diagnose a leak visually, since freon is colorless and odorless. However, there are indirect signs: swelling of the back wall, the appearance of oily spots under the refrigerator (oil comes out along with gas) or a characteristic hissing sound when the tube is damaged. If you notice that the condenser grille at the back is heating unevenly or is cold to the touch, this is a sure sign of a lack of gas.
Repair in this case requires qualifications. The technician must find the location of the leak using a leak detector, eliminate it and fill the system with new freon under a certain pressure. It is impossible to do this on your own without a vacuum pump and a filling scale.
Clogged capillary tube
Another technical malfunction leading to similar symptoms is a clogged capillary tube. This part is a long and very thin copper pipe where throttling (a sharp drop in pressure) of the refrigerant occurs. Through this narrow passage, freon passes from a liquid to a gaseous state, actively cooling.
Over time, oil oxidation products, moisture or paraffin deposits may accumulate in the system. They clog the narrow section of the tube. As a result, the circulation of freon is disrupted: the pressure in the condenser increases, but there is not enough of it in the evaporator. The freezer stops gaining temperature, while residual cold may remain in the refrigerator compartment or, conversely, become warmer than necessary due to a failure of the operating cycles.
Often the blockage is accompanied by strange sounds - gurgling or intermittent humming of the compressor. The motor can turn on, run for a couple of minutes, heat up and turn off via a thermal relay, since it cannot push through the plug in the system.
⚠️ Attention: Attempts to clean the capillary tube yourself using high-pressure nitrogen are dangerous. Incorrect handling can lead to rupture of tubes or damage to the compressor, which will make repairs economically unfeasible.
To eliminate this problem requires professional blowing the system, often using special solvents and subsequent vacuuming. Sometimes it is necessary to replace the capillary itself or the filter-drier, which takes care of the primary purification of freon from moisture.
Malfunction of the defrost system (for No Frost)
If you own a refrigerator with the system No Frost, then the problem may lie in a violation of the defrosting cycle. In such units, moisture from the products is frozen on the evaporator. Periodically (usually every 8-12 hours) the heating element (heating element) is turned on, which melts the ice, and water flows into the pan.
If one of the elements of this circuit fails, the ice does not melt, but grows. The layer of snow becomes so thick that it blocks the air supply channels. The fan continues to move air, but it cannot pass through the ice plug into the refrigerator compartment or circulate effectively inside the freezer. As a result, it is warm in the chambers, although the compressor is working properly.
The main culprits in the breakdown of the defrost system:
- ❄️ Burnt defrost heating element — the heater simply stops heating, the ice does not melt.
- ⏱️ Faulty timer or defrost sensor —"brains" refrigerators do not give a command to turn on the heating.
- 🔌 Wiring break —the wires are often chafed or oxidized in high humidity conditions.
- 🌡️ Evaporator temperature sensor —transmits incorrect data about the ice temperature.
How to check the defrost heating element?
To check the heating element you need a multimeter in dial mode. Unplug the refrigerator and get to the heating element (usually it is located under the plastic panel in the freezer). Using the probes, touch the contacts of the heating element. If the device shows resistance (usually 200-400 Ohms), the heating element is intact. If one or zero, the element has burned out and requires replacement.
You can diagnose this problem by completely defrosting the refrigerator (turn it off for 24 hours). If, after complete defrosting, the appliance began to freeze like new, but after a week or two the problem recurred, it means that the defrosting system is definitely faulty.
Problems with the compressor and start relay
The compressor is the heart of the refrigerator. If it doesn't work correctly, all thermodynamics are disrupted. A common situation: the engine hums, tries to start, clicks and turns off. Or it works, but does not create enough pressure. In this case, the freezer does not reach the required minus, and the refrigerator compartment may work at half capacity.
One of the reasons may be failure start-protection relay. This is a small part that fits onto the compressor contacts. It is responsible for starting the engine and protecting against overloads. If the relay is “stuck” or burnt out, the compressor cannot return to operating mode.
The compressor itself may also wear out. The motor life of modern models is about 10 years, but with frequent power surges or overheating it can be reduced. If the compressor gets very hot (more than 80-90 degrees) and does not freeze, it most likely requires replacement.
☑️ Primary diagnostics of the compressor
Replacing a compressor is a complex and expensive repair that requires resoldering the tubes, evacuating the system and accurately filling with freon. Often the cost of such repairs is comparable to the purchase of a new budget refrigerator.
Failure of electronics and sensors
Modern refrigerators, such as Samsung with a digital inverter or Bosch with the Home Connect system, are crammed with electronics. The control module controls everything. If a breakdown or a firmware “glitch” occurs in its circuit, it can send incorrect commands.
For example, the module may “think” that the target temperature has already been reached in the freezer and not turn on the compressor, although in fact it is warm there. Or it may not properly distribute air flow through the electromagnetic dampers. In models with Full No Frost the damper may jam in the closed position, and the cold simply will not flow into the desired chamber.
Temperature sensors are another weak point. These are thermistors whose resistance changes depending on heat. Over time, their characteristics “float”. If the sensor in the freezer shows the module that it is -25°C (although it is really -5°C), the refrigerator will go into standby mode.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor is silent, there are no lights no | No power, module burnt out | Medium |
| Humming, clicking, won’t start | Relay, compressor, power surge | Medium/High |
| Works constantly, but does not freeze | Freon leak, blockage | High |
| Ice builds up, then stops freezing | Defrost system (heating element, timer) | Low/Medium |
| It makes noise, but there is cold | Fan, vibration, compressor | Low |
⚠️ Attention: If an error code appears on the refrigerator display (for example, F5, E1 or the temperature indicators are flashing), do not ignore it. You should look for the decoding of the code in the instructions specifically for your model, since different brands have codes that mean different breakdowns.
What you can do yourself
Before calling the service, you should perform a number of simple steps that will help eliminate trivial causes or temporarily save products. First, check that the freezer door is closed tightly. The rubber seal could become dirty or deformed, allowing warm air to pass through.
Secondly, assess the load. If you have just loaded several kilograms of warm meat into the freezer, the compressor may not be able to cope. Thirdly, try defrosting the unit. Unplug it from the outlet, open the doors and leave it for at least a day (preferably for two). This will help if the problem is in the ice coat.
After turning on, let the refrigerator run without load for 2-3 hours. If cold appeared, the problem was ice or overload. If after 5-6 hours of operation the freezer is still warm and the compressor is working, you cannot do without a technician.
Frequently asked questions (FAQ)
Why does the top of the freezer freeze, but the bottom does not?
This is a classic sign of a freon leak or blockage. The refrigerant circulates through the evaporator tubes, and if there is a lack of pressure, it only manages to cool the beginning of the circuit (usually the top), and does not reach the bottom. This may also be a sign of an ice-clogged air supply channel in No Frost systems.
Can a refrigerator operate without freon?
Technically, the compressor will work (hum), but there will be no cold anywhere. Freon is a working fluid that transfers heat. Without it or with a critically small amount of it, heat transfer does not occur. It is impossible to operate a refrigerator without freon, since the compressor can burn out from overheating due to the lack of cooling with oil and gas.
How much does it cost to repair if the compressor burns out?
The cost consists of the price of a new compressor, soldering, vacuuming and refilling with freon. On average, this can range from 30% to 60% of the cost of a new refrigerator. For older models, repairs are often not economically feasible.
Why did the refrigerator work after defrosting, but a week later it stopped again?
This indicates a malfunction of the automatic defrosting system. You removed the ice manually, but the automation does not work; the ice has accumulated again and blocked the air circulation. You need to change the heating element, defrost sensor or timer.