The situation when you open the refrigerator door, and it’s warm there, food begins to spoil, while the freezer continues to work properly, causes panic. This is a common problem that can occur both in old Soviet units and in modern No Frost systems. Often, equipment owners immediately call a technician or rush to buy a new device, although in half of the cases the reason lies in simple settings or malfunctions that can be fixed on their own.
Before looking for tools, it is important to understand the structure of your device. In two-compressor models, where different motors are responsible for the refrigeration and freezer compartments, the problem can be localized exclusively in one circuit. If there is only one compressor, then a violation of the circulation of the refrigerant or malfunctions in the defrost system can lead to uneven cooling. Diagnostics begins with assessing the nature of the malfunction: when exactly did the upper compartment stop cooling, were there any defrosts, was the hum of the motor audible.
Ignoring the first signs of equipment malfunction often leads to expensive repairs. If you notice that the temperature in the main chamber is higher than +2...+5 degrees, you should not wait for the food to completely defrost. A critical sign of a serious compressor failure or freon leak is an engine that is running but does not turn off in the absence of cold. In this material we will analyze the main reasons for the failure of the upper chamber and how to eliminate them.
⚠️ Attention: If you smell burning or see sparking in the area of the compressor or wiring, immediately turn off the power to the device. Further operation may lead to a fire.
Features of operation of single-compressor and two-compressor systems
Understanding the operating principle of your refrigerator is the key to correct diagnosis. In two-compressor models, which are often found in brands Liebherr, Bosch i Atlant, an independent cooling circuit is responsible for each compartment. If the upper chamber in such a refrigerator does not cool, but the lower one (freezer) works, this almost always indicates a local problem: a fan malfunction, a clogged capillary tube of this particular circuit, or a failure of the main chamber thermostat.
In single-compressor units, where the cold is generated by one motor and distributed over both compartments, the situation is more complicated. Here, cold air from the freezer (where the evaporator is located) is forced into the refrigerator compartment. If the freezer is working, it means that the refrigerant is circulating, but there is an obstacle to its entry into the upper part. Most often the culprit is a clogged system or malfunction of the dampersregulating the air flow.
Modern systems Total No Frost rely on active air circulation. The fan drives the cold flow through the channels. If you hear the motor humming but there is no cold, the fan may have stopped due to icing or a broken bearing. In such cases, even a working compressor will not be able to cool the food, since the heat exchange is disrupted.
It is also important to take into account the age of the equipment. In older models with a drip defrosting system, the main reason is often the loss of elasticity of the seals or a banal leak of freon through microcracks in the foamed parts of the body. New models more often suffer from electronics and sensors.
Problems with the thermostat and temperature sensors
The thermostat (thermostat) is a device that commands the compressor to turn on and off depending on the temperature inside the chamber. If the refrigerator is not cooling in the top compartment, but the freezer is working, in dual-compressor models, this may mean that the main compartment thermostat is stuck in the off position. The motor simply does not receive a start signal to cool the upper compartment.
In models with electronic control, sensors (thermistors) are responsible for temperature control. Their readings may be distorted due to oxidation of the contacts or failure of the element itself. If the main chamber sensor shows the controller that it is -10 degrees there (although in fact it is +15), the compressor will not turn on. Diagnostics of the sensors requires a multimeter and check their resistance at different temperatures.
Often the problem is solved by simply replacing the thermostat. This is an inexpensive part that you can change yourself if you have electrical skills. However, in some models, for example Indesit or Stinol, access to the thermostat may be difficult due to the need to remove decorative panels.
Symptoms of a malfunctioning thermostat are often confused with a freon leak. But if the freezer is working normally, and the refrigerator is warm, and at the same time you hear relay clicks, but the compressor does not start for the upper circuit, look for a problem in the control electrics.
Malfunctions of the defrost system in No Frost refrigerators
The system No Frost eliminates the need to defrost the refrigerator manually, but it also becomes a source of frequent breakdowns. The operating principle is based on periodically turning on the heating element to defrost the evaporator. If one of the elements of this chain fails, the evaporator becomes overgrown with a “coat” of ice, which tightly blocks the channels for supplying cold air to the refrigerator compartment.
As a result, the freezer, where the evaporator itself is located, continues to freeze (sometimes even too much), and the upper compartment is hot. Air simply cannot pass through the ice plug. The main culprits for this situation:
- ❄️ Burnt defrost heating element —the heating element stops heating, the ice does not melt.
- ❄️ Faulty defrost relay (timer or module) —does not give a command to turn on the heating.
- ❄️ Broken defrost sensor —incorrectly reads the temperature and does not start the defrost cycle.
- ❄️ Clogged drainage hole —water from melting ice does not leave, freezes and blocks the channels.
To confirm this diagnosis, it is often necessary to completely defrost the refrigerator within 24 hours. If after defrosting the device began to cool normally, but after 1-2 weeks the situation repeated itself, the problem is guaranteed to be in the defrosting system.
⚠️ Attention: Do not try to break off the ice with a knife or sharp objects! You can puncture the evaporator, and then repair will become economically unfeasible. Use only a hairdryer to speed up defrosting.
☑️ Diagnostics of the No Frost system
Refrigerant leak and capillary system clogged
If the refrigerator is humming, works without interruption, but there is no cold in the upper chamber (or it is very weak), and the freezer is barely freezes or works only at the rear wall, there is a high probability of freon leakage. The refrigerant circulates in a closed circuit. When a microcrack appears (often in the foamed part of the body or in welding areas), gas comes out, and the pressure is not enough to cool a large volume.
In dual-circuit systems, a leak can only occur in the refrigeration chamber circuit. In this case, the freezer will work perfectly, since its circuit is sealed, and the upper part will stop cooling. Clogged capillary tube gives similar symptoms: the compressor tries to pump freon, but cannot due to a plug of oil or moisture, circulation is disrupted.
The table below will help differentiate the symptoms of leakage and blockage:
| Symptom | Freon leakage | Capillary blockage |
|---|---|---|
| Compressor operation | Works constantly, without turning off | Works jerkily or constantly, gets very hot |
| Condenser temperature (grid at the back) | Warm only at the beginning of the circuit, then cold | Hot to the point of blockage, then cold |
| Frost on the evaporator | Absent or uneven | Can only be at the beginning of the tubes |
| Sound during operation | Normal hum | Gurgling, hissing |
Repair in the event of a leak or blockage requires calling a technician with equipment to evacuate the system and refill with freon. It is impossible to fix these faults on your own without a special tool.
Why can’t you just add freon?
If there is a leak in the system, simple refilling will only give a temporary effect. After a month, the gas will come out again, and the compressor, running idle without oil (which circulates along with freon), may burn out. It is necessary to find the location of the leak.
Fan breakdown and problems with dampers
In refrigerators with forced air circulation (No Frost), the fan is responsible for the distribution of cold. It is located in the freezer compartment and blows cold air through the ducts into the refrigerator compartment. If the fan stops, the cold remains below, and the heat remains at the top.
The reasons for stopping the fan can be different:
- 🌀 Icing of the blades —due to a malfunction of the defrosting system, ice blocks rotation.
- 🌀 Combustion of the motor winding —the fan requires replacement.
- 🌀 Mechanical obstacle —a frozen piece of ice or a foreign object.
Also in some models (for example, LG, Samsung) special dampers are installed (dampers) that regulate the volume of supplied air. If the damper is stuck in the closed position, air simply does not enter the chamber. This often happens when the damper drive breaks down or the electronics are not calibrated.
Checking the operation of the fan is simple: open the door of the refrigerator compartment. In a working device, when the door is open (when the limit switch is triggered), the fan should go silent. If you do not hear it working even when the door is closed and active cooling is in progress, the problem is obvious. No Frost when the door is open (when the limit switch is triggered), the fan should stop. If you don’t hear it working even when the door is closed and active cooling is in progress, there is a problem.
⚠️ Attention: When checking the fan, do not leave the door open for more than 5-10 minutes. A lot of warm, moist air will enter the chamber, which will accelerate the formation of a new ice crust on the evaporator.
The influence of seals and operating rules
The reason does not always lie in complex mechanics. Often the refrigerator does not maintain temperature due to a banal seal failure. If the rubber seal of the refrigerator door is worn out, dirty or deformed, warm air constantly flows inside. The compressor (or system) cannot cope with the heat flow, and the temperature rises.
You can check the seal using a sheet of paper: clamp it with the door around the perimeter. If the sheet is pulled out without force, the seal does not fit. It is also worth checking whether the door is warping due to improper installation or overloading of the shelves.
Another factor is loading rules. If you put a pot of hot soup in the refrigerator or loaded it with fresh food at room temperature, the appliance may temporarily not cope with cooling. In this case, the freezer, which has priority or a separate circuit, will continue to operate, and the temperature in the main chamber will temporarily increase.
It is also important to ensure that products do not block the outlet openings of the air ducts inside the chamber. A clogged channel will not allow cold air to pass to the products, even if the system is working properly.
When you need to call a technician: assessing the feasibility of repair
Independent repair is possible when replacing thermostats, fans, heating elements or seals. These parts are available and the replacement process is described in the instructions. However, there are situations when you cannot do without a professional.
If a freon leak is diagnosed in the foamed part of the housing (inside the walls of the refrigerator), repairs often become unprofitable. Craftsmen may suggest installing an external evaporator (“crying” on the back wall inside the chamber), but this worsens the appearance and reduces the usable volume. In old refrigerators, it is cheaper to buy a new one than to overhaul the circuit.
Also, complex repairs are required when the electronic control module fails. If the “brains” of the refrigerator are burned out, it is necessary to reflash or replace the board, which requires qualifications and the availability of spare parts specifically for your model Electrolux, Beko or another brand.
Make the decision on repair or replacement based on the age of the equipment. If the refrigerator is more than 10-12 years old and requires replacement of the compressor or overcooking of the case, it is more economically profitable to purchase a new model with a guarantee and a modern energy efficiency class.
Frequently asked questions (FAQ)
Why did the refrigerator stop cooling immediately after defrosting?
If you defrosted the refrigerator for less than a day (they just turned it off for a couple of hours), the ice in hidden channels or on the evaporator may not have had time to completely melt. When turned on, the water froze and created a plug. Repeat defrosting, leaving the appliance turned off for at least 24 hours with the doors open.
Is it possible to operate the refrigerator if the upper chamber is not cold?
For a short time - yes, if you transfer perishable foods to the freezer. However, prolonged operation in this mode is harmful to the compressor, which may work without interruption, trying to gain temperature. This leads to overheating and eventual breakdown of the motor.
How much does it cost to repair if the refrigerator does not keep cold?
The cost depends on the breakdown. Replacing a thermostat or fan is relatively inexpensive. Freon refilling and leak detection are more expensive. The exact price can be found out only after diagnostics by a technician on site.
Why is the back wall of the refrigerator covered with ice, but it’s warm inside?
This is a classic sign of air circulation problems or problems with defrosting in the systems. No Frost. Ice on the back wall (where the evaporator is located) blocks heat transfer. A check of the defrost heating element and sensors is required.