The situation when the refrigerator starts to work incorrectly often takes you by surprise. It is especially alarming when upper chamberintended for storing fresh food turns into a freezer. Instead of chilled vegetables and soups, you find frozen lumps, torn milk cartons and frost on the walls. This is not just an inconvenience, it is a signal that the temperature control system has failed.
There may be several reasons why refrigerator it begins to freeze excessively in the upper compartment. This ranges from a simple setting error to a serious electronic malfunction or refrigerant leak. Understanding the operating principle of your unit, be it No Frost or a drip system, will help you quickly localize the problem.
In this article we will analyze in detail the main factors influencing the temperature regime. We will consider both simple actions that you can perform yourself, and complex technical malfunctions that require the intervention of a specialist. The main sign of a serious breakdown is the continuous operation of the compressor without stopping. If your unit hums 24 hours a day, and the products on the top shelf are covered with ice, you cannot hesitate to diagnose.
Checking settings and user errors
Before looking for complex breakdowns, it is worth eliminating the human factor. Modern models, such as LG or Samsunghave complex control systems where it is easy to get confused. Sometimes an accidental touch on the control panel is enough to reset the settings. Check if the mode "Super Freeze" or “Max Cool” is set. In this mode, the compressor operates at its maximum, ignoring standard temperature thresholds.
Also pay attention to the position of the thermostat. If you have a manual control, the knob may have moved to the maximum cold position. In electronic models, a failure could occur due to a power surge. Try performing a full factory reset. To do this, you often need to hold down a certain combination of buttons or simply disconnect the device from the network for 15-20 minutes.
⚠️ Attention: If after resetting the settings and returning to standard parameters the situation has not changed within 6-8 hours, the problem lies deeper than just a software failure.
Do not forget about the loading density of the cameras. If you have just put a large amount of warm food into the refrigerator, the system may have automatically increased the cooling power. However, this is a temporary effect. If the chamber is empty and the cold is extreme, look for the reason in the sensors.
Thermostat malfunctions and its impact on operation
One of the most common reasons why the refrigerator is very cold in the upper compartment is the failure of the thermostat. This element is responsible for controlling the temperature and sending a signal to the compressor to stop. If the thermostat contacts “stick” in the closed position, the compressor continues to work indefinitely, freezing the chamber.
In models with a drip defrosting system, the thermostat is usually located inside the chamber. Its capillary tube senses temperature changes. Over time, the mechanism wears out and it stops opening the circuit when the required values are reached. In models Indesit i Atlant this is a common problem after 5-7 years of operation.
To diagnose a malfunction, it is often necessary to ring the contacts with a multimeter. If, when the sensor is cooled (for example, by lowering it into cold water), the resistance does not change or the circuit does not break, the part must be replaced. This is not the most complicated procedure, but it requires care so as not to damage other elements.
It is worth noting that in two-compressor refrigerators, failure of the thermostat in the upper chamber does not affect the operation of the lower chamber. However, in single-compressor units with one evaporator, a malfunction can lead to an imbalance of temperatures throughout the entire volume.
Problems with the defrost sensor and the No Frost system
If your refrigerator is equipped with a system No Frost, a whole set of sensors is responsible for the temperature regime. The evaporator defrost sensor plays a key role. If it is faulty and “lies”, telling the controller that the evaporator has not yet warmed up, the cooling cycle is not interrupted. As a result, cold air continues to be pumped into the chambers.
Often the problem lies not in the sensor itself, but in the formation of an ice plug in the air supply channel. Ice blocks the damper and it gets stuck in the open position. The cold flow from the freezer flows freely into the upper compartment, freezing the entire contents. This is typical for models Bosch and Siemens.
- ❄️ Symptoms: a “fur coat” is formed on the back wall of the upper chamber, the products at the back wall freeze, but at the door they can remain warm.
- ⚙️ Cause: failure of the defrosting heating element, faulty timer or burnt out defrost system fuse.
- 💨 Consequence: impaired air circulation and local overcooling of areas near the supply channel.
Diagnostics of the No Frost system requires disassembling the rear panel of the freezer. It is necessary to check the resistance of the heating element and the integrity of the sensor circuit. If the heating element does not heat, the evaporator becomes overgrown with ice, which can then fall into pieces into the air ducts, blocking the damper.
⚠️ Attention: When defrosting the refrigerator to check the system, never use sharp objects to chip ice - there is a high risk of breaking through the evaporator, which will lead to expensive repairs.
Freon leak and compressor operation
Paradoxically, a refrigerant leak can also lead to excessive frost in one of the chambers, although more often we observe a complete absence of cold. If the level freon drops slightly, the compressor tries to compensate for the lack of cooling capacity by continuous operation. In single-compressor models, this can lead to the fact that the evaporator located in the freezer will be cooled to extreme temperatures, and excess cold will go into the upper chamber.
In such cases, the compressor works non-stop, gets very hot, and uneven frost may appear on the walls of the chambers. In the leak area (often this is the foamed part of the body or pipe joints) there may be no frost at all. It is difficult to determine a leak visually; the use of a leak detector or soap solution is required in open areas of the circuit.
If a leak is confirmed, simple gas filling will not help. It is necessary to find the place of damage, seal it and only after evacuating the system, fill it with new refrigerant. Attempts to simply add gas will lead to repeated failure in a short time.
Is it possible to determine a leak by sound?
If there is a strong leak, you can sometimes hear a hissing or whistling sound in the area of the back wall or at the bottom of the refrigerator, but more often the process occurs silently.
Failures of the control module and electronics
In modern “smart” refrigerators, such as LG with a linear compressor or Samsung with a digital inverter, an electronic control module is responsible for all processes. If the compressor control triac on the board burns out or there is a failure in the firmware, the “brains” of the device may issue erroneous commands.
The module may not receive signals from temperature sensors due to broken wiring or oxidation of contacts. As a result, he “thinks” that the chamber is warm and turns on the compressor at full power. Electronics diagnostics require special knowledge and equipment.
Flashing or resetting errors often helps before completely replacing the board. However, if the board shows signs of burning, swollen capacitors or oxides, repair may not be economically feasible compared to replacing the assembly.
The influence of seals and chamber tightness
It would seem that leakage should lead to loss of cold. But if the rubber seal door of the upper chamber is damaged or dirty, there is a constant flow of warm, moist air. The cooling system responds to rising temperatures by turning on the compressor. In an attempt to cool the incoming heat, the unit wears out, which leads to severe freezing of products located closer to the source of cold.
In addition, moisture from the air actively settles on the walls and freezes, forming an ice crust. This is especially true in winter, when indoor humidity is high. Check the tight fit of the door: a sheet of paper clamped around the perimeter should be pulled out with force.
If the seal is deformed, you can try to restore it using a hair dryer (heating and straightening) or replace it with a new one. A dirty seal must be thoroughly washed with warm water and soap, removing the sticky coating that interferes with tight closure.
Diagnostic table of the main symptoms
For convenience, we systematize the main signs and probable causes in a table. This will help you quickly navigate the nature of the malfunction.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The compressor is running non-stop, there is ice in the chamber | The thermostat or temperature sensor is faulty | Replacing the sensor/thermostat |
| Ice only at the back wall, the food at the door is normal | The air exhaust channel is clogged or the damper is faulty | Defrosting, checking the No Frost system |
| The refrigerator is humming, but there is little cold, although it freezes a lot | Freon leak | Searching for leaks, vacuuming, refilling |
| The display lights up error, modes do not switch | Control module failure | Board diagnostics, flashing or replacement |
When you need to call a technician
Independent repair is possible if we are talking about replacing the thermostat in an accessible place, defrosting or cleaning the seals. However, if the problem lies in a sealed circuit (freon leakage), in the electronic module, or requires disassembling the foamed parts of the case, it is better to turn to professionals.
Unskilled intervention can lead to the final failure of the equipment. The technician has the necessary tools to diagnose pressure in the system, check electrical circuits under load and carry out complex repair work.
Remember that regular maintenance and timely defrosting (for drip systems) extend the life of your refrigerator and prevent many of the problems described.
☑️ Actions before calling a technician
Frequently asked questions (FAQ)
Why does water freeze in the upper chamber, but everything is fine in the lower chamber?
This is typical for single-compressor refrigerators. If the thermostat or damper is faulty, cold air from the freezer will flow uncontrollably into the upper compartment. Also, the cause may be a local leak of freon at the beginning of the evaporator circuit.
Is it possible to operate a refrigerator if it is very cold?
For a short time - yes, but not for long. Constantly working at the limit wears out the compressor. In addition, the food in the upper chamber will lose its properties, and ice can block the ventilation system, which will lead to overheating of the motor.
How often should you defrost the refrigerator to avoid problems?
No Frost systems do not require manual defrosting, but it is recommended to wash and defrost them once a year for hygiene. Drip systems (“crying wall”) need to be completely defrosted 1-2 times a year to clean the drainage and check the operation of the thermostat.
Is freezing of food related to the quality of electricity in the network?
Indirectly - yes. Voltage surges can damage the control module or sensors, resulting in incorrect operation. For protection, it is recommended to use a voltage stabilizer or surge protector.