The situation when the refrigerator continues to work, hums and illuminates the interior, but stops cooling food in the upper compartment, is one of the most common and alarming for the owner. Often this happens suddenly: you open the door to take milk, and there is room temperature, while the freezer continues to freeze properly. Such a mismatch in temperature conditions indicates a violation of the circulation of the refrigerant or a malfunction in the air flow control system.
You should not panic right away, since in many cases problem it lies not in a compressor failure, but in a banal blockage or software failure of the electronics. However, this symptom cannot be ignored: a prolonged lack of cooling in the upper chamber will lead to spoilage of food and, possibly, to more serious damage to the units of the unit. Understanding the principles of operation of your model will help you quickly localize the malfunction.
In this article we will analyze in detail the mechanical and electrical reasons why refrigerator does not keep the temperature at the top, consider the features of the systems No Frost and static cooling, and also determine what steps you can take yourself, and when it is necessary to call masters.
Fundamental differences in the operation of cooling systems
To understand where to look for the reason for the lack of cold, you need to clearly understand how exactly your refrigerator works. In older and budget models, it is used drip system, where the evaporator is located in the rear wall of the upper chamber. The cold falls down naturally or is transmitted through a common partition.
Modern units most often use the system No Frost (or Low Frost). In such models, the main evaporator is located in the freezer compartment (usually at the bottom), and cold air is forced into the upper compartment using a special fan through air ducts. If there is no cold in the system from above, but the freezer is working, this almost always means a problem with air circulation or defrosting of the evaporator. No Frost there is no cold from above, but the freezer is working, this almost always means a problem with air circulation or defrosting the evaporator.
There is also a dual-circuit cooling system, where each chamber is responsible for its own independent circuit and its own compressor (or one compressor with flow separation). In such cases, a breakdown of the upper chamber circuit does not affect the operation of the freezer, but repairs require professional diagnostics.
Mechanical obstacles to air circulation
The most common, but common reason is violation of the rules of operation and loading of products. In systems with forced air circulation (No Frost), it is critical not to block the outlet openings of the air ducts. If you tightly pack the shelf with bags, air simply cannot enter the upper part of the chamber.
Another important factor is the tightness of the door. If the rubber seal wears out, gets dirty or the door is warped, warm air from the room will constantly flow inside. The compressor will work hard, trying to cool the volume, but due to the constant influx of heat, the temperature will not drop to the desired values.
It is also worth checking whether the door has frozen to the body or shelves due to ice, which sometimes happens when the defrost system malfunctions. Ice can block normal closure, creating a gap that is invisible to the eye.
Pay special attention to the room temperature. If the refrigerator is located next to a radiator, oven, or in direct sunlight, the efficiency of heat transfer drops sharply. In such conditions, condenser does not have time to cool down, and the cooling system does not work correctly.
Malfunctions of the defrost system in No Frost refrigerators
If you have a model with a system No Frost in the upper chamber warm, but the freezer is cold, with an 80% probability the problem lies in the automatic defrosting system. A “coat” of ice grows on the evaporator, hidden behind a plastic panel. This ice blocks the channels through which the fan should drive cold air upward.
Three main elements are responsible for the defrosting process: Heating element (heater), Thermostat (temperature sensor) and Timer (or electronic module). Failure of any of them leads to the fact that the ice does not melt, but accumulates. The fan continues to hum, but air does not pass through the ice plug.
What does a frozen evaporator look like?
If you remove the back panel in the freezer, you can see that the evaporator is completely or partially covered with a thick layer of ice, and the ventilation hole is clogged with a snow-like mass.
This problem can be diagnosed by a characteristic sound: if the fan is humming, but no air is felt from the holes in the upper chamber, it means that the path is blocked by ice. Sometimes ice can damage the fan blades, and then you will hear a cracking or humming sound.
Problems with the fan and damper
The fan is the “heart” of the cold distribution system. If it stops, cold air remains in the freezer without reaching the upper compartment. The reasons for stopping can be different: from freezing of the motor bushing to winding combustion or breakage of the impeller.
In models with electronic control, a damper (damper) is often found, which regulates the amount of cold air supplied. It opens and closes at the command of the thermostat. If the damper mechanism is stuck in the closed position or the drive motor is burned out, the upper chamber will remain warm.
You can check the operation of the fan by opening the freezer door and pressing on the corresponding sensor (simulating closing). If it hums when the door is closed, but goes silent when the door is open (when you press the button), the mechanics are working properly. If there is silence even with the door closed, the fan is faulty.
| Symptom | Probable cause | Check method |
|---|---|---|
| Noise/crackling in the freezer | Ice on fan blades | Visual inspection after defrosting |
| The fan is silent | The motor is burnt out or there is no power | Test with a multimeter |
| There is air, but warm | The compressor is faulty or there is a leak | Checking the pressure in the system |
| It is cold or not | Sticking damper-regulator | Observing operation damper |
Freon leakage and compressor malfunction
A more serious situation arises when freon has formed in the system. In two-chamber refrigerators with one compressor, a sequential scheme is often used: first, freon passes through the freezer chamber, cooling it, and only then enters the circuit of the upper chamber. With a small pressure leak, freon is only enough for the first circuit (freezer), and it simply does not reach the top in the required quantity. refrigerant leak (freon). In two-chamber refrigerators with one compressor, a sequential scheme is often used: first, freon passes through the freezer chamber, cooling it, and only then enters the circuit of the upper chamber. With a small pressure leak, freon is only enough for the first circuit (freezer), and it simply does not reach the top in the required quantity.
In this case, the freezer can operate normally or even with increased intensity, trying to compensate for the lack of refrigerant, while the upper compartment will have a positive temperature. It is difficult to determine a leak visually; the use of a leak detector is often required.
☑️ Signs of a freon leak
Failure of the system itself is also possible compressor. If it has lost performance (for example, wear of the piston group), it will not be able to create the necessary pressure to pump freon through both circuits. As a result, it is the farthest point of circulation that suffers - the upper chamber.
Failures in the operation of electronics and sensors
Modern refrigerators are controlled by complex electronic modules. If thermostat (mechanical regulator) or temperature sensor (in electronic models) gives incorrect readings, the brain of the refrigerator may “think” that the upper chamber is already cold enough and does not turn on the cooling.
Often the sensors “lie” due to oxidation of the contacts or miscalibration. On models with a display, this may be accompanied by erroneous temperature readings or error codes (for example Error F1 or flashing lights).
⚠️ Attention: Before replacing any electronic components or sensors, be sure to unplug the refrigerator for at least 15-20 minutes. This will clear errors from the control board and avoid electric shock.
Sometimes the problem is solved by flashing the control module or completely replacing it if there is a breakdown of the board elements due to a voltage surge in the network.
When it is necessary to call a technician
There are a number of situations when self-repair is not only ineffective, but also dangerous. If you suspect freon leakyou will need specialized equipment to evacuate the system and charge it with refrigerant. It is almost impossible to independently find the location of a micro-leak in a foamed case.
Replacing a compressor or repairing sealed systems also requires skills in working with a blowtorch, nitrogen and refrigerants. Inept actions can lead to fire or final damage to the unit.
⚠️ Attention: If you smell burnt wiring or see sparking in the compressor area, immediately unplug the cord from the outlet. The operation of such a device is prohibited.
In addition, if after complete defrosting (24 hours) the problem with the lack of cold in the upper chamber returned after 1-2 days, this is a clear signal of a technical malfunction of the components (heating element, timer, sensor), requiring professional diagnostics.
Why is it warm in the upper chamber, but the freezer is working?
Most often this indicates a violation of air circulation (the air duct is clogged with ice in No Frost systems) or a freon leak when there is not enough pressure for the second cooling circuit. The temperature sensor may also fail.
How long does it take to defrost the refrigerator?
It takes at least 24 hours for the ice in the hidden channels of the evaporator to completely melt and restore operation of the system. Defrosting for 2-3 hours is often not enough to solve the problem.
Is it possible to use the refrigerator if the top does not freeze?
Short-term - yes, but the food in the upper chamber will quickly spoil. Long-term operation in this mode is dangerous for the compressor, which can overheat while working without stopping.
How to check if the fan is working?
Open the freezer door, find the door sensor button (usually at the end) and press it with your finger, simulating closing. If the fan starts, it is working. If not, replacement is required.