The situation when the upper part of the refrigerator continues to cool food, and the lower freezer suddenly stops freezing, causes panic in any home cook. This is indeed an alarming signal indicating a problem with refrigerant circulation or a malfunction in the temperature control system. In contrast to a complete failure of equipment, a partial loss of refrigeration capacity often indicates specific malfunctions that require immediate intervention.
The first thing to do is to assess the scale of the problem and rule out trivial causes, such as a loose door or overloading the chamber with products. However, if you notice that temperature in the freezer it has risen above -12 degrees, and a thick layer of ice has appeared on the walls or, conversely, complete dryness while the compressor is running, then the matter is more serious. In this article, we will analyze in detail the mechanics of the process and help diagnose the breakdown.
Modern models, whether Indesit, Atlant or premium Liebherr, use similar operating principles, but have their own design features. Understanding exactly how your unit should behave normally will help you quickly identify an anomaly. Do not rush to call a technician right away, as in some cases the problem can be solved on your own in 15 minutes.
Principle of operation and distribution of cold
To understand why fridge compartment works, but the freezer does not, you need to understand the physics of the process. In most modern models with the system No Frost cold is generated in the freezer compartment, and then the fan drives this air through the channels to the upper part. If the compressor is working properly and creates cold, but it does not reach the evaporator or does not circulate, the top can be cooled by inertia or due to residual cold, while the bottom has already “defrosted.”
In two-compressor models, the situation is different: here a separate motor is responsible for each circuit. If you have just such a unit, then a freezer failure while the refrigerator is running clearly indicates a problem with the lower compressor or its control circuit. In single-compressor models, such as the popular Bosch or Electrolux, the refrigerant passes through both circuits sequentially, and a violation in any node can lead to an imbalance of temperatures.
⚠️ Attention: If you hear the hum of the compressor, but there is no cold anywhere, or the compressor runs without stopping, this may indicate a leak. Freon. In this case, further operation of the equipment is useless and even harmful to the motor.
The key element here is evaporatorwhich is hidden behind the back wall. It is on this that the refrigerant boils, taking heat from the chambers. If the boiling process is disrupted or heat exchange is blocked by ice, the entire system stops functioning correctly. It is important to understand that temperature sensors read readings at certain points, and if it is warm there, the compressor will work hard, trying to achieve the set parameters.
Why can the top be cold, but not the bottom?
In some older models with a drip defrosting system, cold air naturally falls down. If the freezer is warm and the refrigerator is cold, this may mean that the seal of the partition between the chambers is broken or the air flow channel is clogged.
Diagnostics of the No Frost and defrosting system
The most common reason why freezer compartment stops freezing, but remains in the refrigerator acceptable temperature lies in the automatic defrosting system. In units No Frost on the evaporator, frost is constantly formed from the moisture contained in the products and air. Periodically, this ice must be melted by a heating element. If this process is disrupted, the ice coat grows and tightly blocks the fan.
As a result, the fan blowing the evaporator cannot drive cold air into the chambers. The freezer stops getting cold and food starts to spoil. At this time, the refrigerator compartment can still maintain its temperature for some time due to residual cold or the operation of a defrosting heating element, which is sometimes mistakenly perceived as heat. Diagnosing this problem requires a careful inspection.
You need to completely defrost the refrigerator. This is not just “turn it off for an hour,” but leave the equipment unplugged for at least 24 hours with the doors open. This is the only way to be sure that the ice in hard-to-reach places in the air ducts will completely melt. After turning on, check the operation of the fan: it should make noise a few minutes after the compressor starts.
☑️ Diagnostics of the defrost system
If after defrosting the equipment started working, but after 1-2 weeks the problem recurred, it means that one of the elements of the system has failed defrost. Most often, the defrost temperature sensor burns out or breaks. In models Heater heating elements or the defrost temperature sensor breaks. In models Samsung and LG the contacts on the heater itself are also often broken due to corrosion.
Problems with the fan and air circulation
Even if the defrost system is working properly and there is no ice on the evaporator; cold may not enter the chamber due to a fan malfunction. This unit is responsible for forced air circulation. If it stops, cold air remains in the evaporator area, and warm air remains in the chambers. In this case, it may be cooler in the refrigerator compartment, since the cold air is heavier and partially falls down, but there will not be full frost.
Signs of a fan malfunction are often heard without opening the panels. You may notice:
- 🔇 Complete absence of sound from the fan after closing the door (in many models it turns off when opened).
- 🔊 Extraneous noise, crackling or humming, indicating destruction of bearings or ice freezing on the blades.
- ❄️ Uneven cooling: the back wall is cold, but the door is warm.
In some models, for example, in old Stinol or Indesit, the fan may jam due to pieces of ice that have broken off from food. In other cases, like w Whirlpool, the problem may be in the electronics, which do not supply voltage to the fan motor. The check begins with a visual inspection: if the blades spin tightly by hand, the bearing requires replacement.
Compressor malfunctions and refrigerant leaks
If defrosting did not help and the fan hums normally, but temperature in the freezer does not go down, the problem may be in the “heart” of the refrigerator - the compressor, or in the absence of the refrigerant itself. A freon leak is an insidious malfunction. Gas can escape through microcracks in sealed connections or through corrosion of tubes in the foamed part of the case.
Leakage symptoms often develop gradually. First, the refrigerator begins to freeze worse, the compressor works longer, then the freezer stops freezing completely, and in the refrigerator compartment the temperature rises to +10...+15 degrees. However, during the transition period, a paradox may be observed: the refrigerator is still cold (since the freon is a little, but there is enough for the primary circuit), but the freezer no longer works.
| Symptom | Probable cause | Actions |
|---|---|---|
| Compressor hot, works constantly | Freon leak or capillary blockage | Call a technician for refilling |
| The compressor is cold, clicks and does not start | Malfunction of the starting relay or motor | Replacing the relay or compressor |
| The tubes on the rear wall are warm only at the inlet | Partial leak or blockage | Diagnostics of pressure in the system |
| Frost only at the beginning evaporator | Lack of freon | Searching for leaks and refilling |
It is almost impossible to fix a leak or replace the compressor on your own without special equipment (vacuum pump, pressure gauge station, burner). Refilling with freon requires precise knowledge of the type of refrigerant (R600a, R134a) and its quantity indicated on the nameplate. An attempt to simply “add gas” without evacuation of the system will lead to rapid breakdown of the compressor due to the presence of moisture and air.
⚠️ Attention: Freon R600a (isobutane), used in many modern models, is explosive. Carrying out leak detection and soldering work in domestic conditions is strictly prohibited!
Failures in the electronic control module
In modern refrigerators with electronic control, control moduleis responsible for the distribution of cold. It receives signals from temperature sensors in the chambers and controls the activation of the compressor, fan and heating elements. If the control board is “buggy”, it may not send a command to turn on the compressor for the freezer (in dual-circuit systems) or incorrectly read sensor readings.
Often the problem lies in oxidation of the sensor contacts or a break in the wiring going from the sensor to the board. For example, in refrigerators Beko or Ariston there are known cases when the evaporator temperature sensor “lied”, telling the board that defrosting was completed, although the ice had not yet melted. As a result, the compressor did not turn on in time, and the chamber defrosted.
Electronics diagnostics require a multimeter and skills in reading electrical circuits. It is necessary to “ring” all sensors to ensure that their resistances match at a certain temperature. If the values deviate significantly from the norm, the sensor must be replaced. It is also worth inspecting the board itself for swollen capacitors or traces of burning.
Mechanical damage and wear of seals
Do not forget about banal mechanical reasons. If sealing gum the door of the freezer is worn out, dirty or deformed, warm air from the room constantly enters the chamber. The compressor tries to compensate for the heat by working non-stop, but due to the constant flow of heat, the temperature does not drop to the desired values.
You can check the tightness with a simple test with a sheet of paper. Clamp the sheet with the door around the perimeter. If it is pulled out without resistance or falls out on its own, the seal is broken. The cause may also be door misalignment due to improper installation or loose hinges. In this case, the cold simply “escaps” out.
Mechanical damage also includes dents on the body, especially in the area of the freezer. If the thermal insulation layer is punctured during transportation or the internal circuit is deformed, this may lead to disruption of refrigerant circulation or depressurization. In such cases, repair is often not economically feasible.
When you need to call a technician
Independent repair is possible only in case of problems with defrosting, replacing the fan or sensors that are accessible without breaking the sealed circuit. However, if you encounter the following symptoms, you cannot do without a professional:
- 🛠️ The compressor needs to be replaced or refilled with freon (licensed gas and equipment is required).
- 🔧 A leak has been detected in the foamed part of the housing (installation of an external evaporator is required).
- 💻 The electronic control module is faulty, requiring re-soldering of components or flashing.
- 📉 The capillary pipeline is clogged (high pressure nitrogen purging is required).
A call to a specialist is also necessary if, after self-defrosting and checking the fan, the problem does not disappear within a day of operation. Continued operation of the refrigerator in the “under-frost” mode will lead to spoilage of food and possible failure of the compressor due to operation in emergency mode.
How long should the refrigerator operate after defrosting to gain temperature?
Usually, the refrigerator requires from 4 to 8 hours to fully return to mode after a 24-hour defrost. In the first 2-3 hours, the freezer should already begin to freeze. If after 6-8 hours of compressor operation the temperature in the freezer is above -10 degrees, then the problem is not a frozen evaporator, but a technical malfunction.
Is it possible to use an additional fan inside the freezer?
It is strictly not recommended to install third-party devices inside the chambers. This disrupts the designed aerodynamics of air flow and can lead to freezing of the blades and a short circuit. In addition, any excess heat source (fan motor) inside the chamber will prevent the thermostat from correctly turning off the compressor.
Why does the refrigerator not turn on for a long time after defrosting?
Some models with electronics have protection against restarting. The compressor will not start until a certain amount of time has passed (usually 10-15 minutes) or until the sensors indicate that the system is ready to operate. Also, the cause may be a faulty start relay, which is “stuck” after a power surge when turned on.
Does the amount of food in the freezer affect its operation?
Yes, it does. An empty freezer loses cold faster when the door is opened, but also gains temperature faster during operation. A full chamber (loaded with products or special cold accumulators) operates more stable, since the products accumulate cold. However, you cannot stuff the chamber “all the way” - this will block the air ducts and disrupt circulation.