The situation when in the main compartment of the refrigerator, designed for storing food at a temperature of about +4°C, water suddenly begins to freeze or milk becomes covered with ice, causes bewilderment among many owners of household appliances. This phenomenon signals that the temperature regime inside the chamber is disturbed and the cooling system is not working correctly, producing excess cold where it should not be. Impaired temperature balance can lead to rapid spoilage of products, changes in their structure and taste, so the problem cannot be ignored.
Most often the reason lies in malfunctions of the automation that controls the compressor, or mechanical malfunctions of the refrigerant circulation system. Modern models, such as Indesit, Atlant or Beko, are equipped with complex electronics, which can also malfunction, sending incorrect signals to start the engine. Understanding the operating principle of your unit will help you quickly diagnose a breakdown and avoid costly repairs at a service center.
In this article we will analyze in detail all possible factors, from simple operating errors to serious technical malfunctions. You will learn how to independently check the condition of the seals, adjust the regulators and determine whether a technician's intervention is required. A critical sign of a breakdown is the formation of an ice coat exclusively on the back wall when the compressor is running without shutdowns.
Faults of the thermostat and temperature sensors
One of the most common The reason why the refrigerator starts to freeze in the positive compartment is the failure of the thermostat or temperature sensor. It is this component that is responsible for controlling the temperature inside the chamber and sends a signal to the compressor to turn on or off. If thermostat sticks in the “on” position or transmits incorrect data to the electronic module, the motor-compressor operates continuously without pausing for rest.
As a result of constant cooling, the temperature in the main chamber drops below zero, which leads to freezing of liquids and spoilage of vegetables. In older mechanically controlled models, the thermostat bellows tube itself, which responds to changes in freon pressure, often breaks. In modern devices with a system No Frost or Full No Frost electronic sensors are responsible for this process, which can oxidize or generate an error due to power surges.
You can diagnose the problem by paying attention to the operating mode of the refrigerator. If it hums constantly and does not turn off for hours, and the food in the main chamber is covered with frost, then with a 90% probability it is the temperature controller that is to blame. Replacing this part usually does not require complex equipment, but requires precise selection of the model for a specific brand, be it LG, Samsung or Stinol.
⚠️ Attention: Before replacing the thermostat, be sure to disconnect the refrigerator from the power supply. Working with live electrical components is dangerous and can lead to a short circuit.
Problems with the cold removal system and damper
In refrigerators with a system No Frost cold is produced in the freezer and then supplied to the plus compartment through special channels. The cold air flow is controlled using an electronically controlled air damper. If the damper mechanism gets stuck in the open position or the drive motor fails, an excess amount of icy air enters the main compartment.
This leads to local hypothermia, especially on shelves located closer to the duct outlet. Users often notice that food freezes unevenly: for example, a bottle of water standing at the back wall turns into ice, while food on the bottom shelf remains warm. Defective damper typical for multi-chamber models, where one compressor serves several compartments.
It is also worth checking the condition air ducts Sometimes they can become clogged with pieces of ice or food, which impairs circulation. In some cases, completely defrosting the unit within 24 hours helps, but if the problem returns immediately after turning it on, it means that the mechanical part of the air distribution system requires repair or replacement.
How to check the damper without disassembling?
For initial diagnosis, you can listen to the operation of the refrigerator. If the damper is working properly, when the temperature changes, you should hear a quiet click or hum from the drive motor. If the refrigerator is working, but there are no sounds of air redistribution, the drive may be jammed with ice or the motor winding has burned out. It is better to carry out accurate diagnostics with a multimeter, checking the resistance of the windings.
Refrigerant leak and disruption of the cooling cycle
Paradoxically, a freon leak can also cause food to freeze in the positive chamber, although it would be more logical to expect a complete absence of cold. The mechanism of this phenomenon is associated with changes in pressure in the system and the characteristics of the compressor when there is a lack of refrigerant. When the amount freon in the circuit decreases critically, the compressor is forced to work almost non-stop, trying to reach the set temperature.
Due to continuous operation, the evaporator in the freezer is supercooled, and the cold transferred to the main compartment becomes too intense. In addition, when a leak occurs, the pressure balance may be disrupted, which leads to the formation of ice plugs in the capillary tube. This causes an abrupt change in temperature: either intense cold or its absence.
Signs of a leak are often swelling of the rear wall of the refrigerator (in the place where the tubes are baked) or, conversely, the lack of heating of the condenser grille at the back. If you notice that the refrigerator runs for days, consumes more electricity, but does not freeze well in the freezer and freezes in the main chamber, most likely the circuit has depressurized.
| Symptom | Probable cause | Recommended action |
|---|---|---|
| The compressor does not turn off | Thermostat is faulty or freon is leaking | Call a technician to measure the pressure |
| Ice only at the back wall | The damper or sensor is faulty | Check the No Frost system |
| Balling of the rear wall | Corrosion and leakage in the foamed part | Requires complex repairs with re-warping |
| The refrigerator is warm, but it is humming | Refilling with refrigerant and searching for a breakdown |
Failures in the electronic control module
Modern refrigerators such as Bosch, Siemens or Electrolux, are controlled by complex electronic boards. It is the module that receives signals from sensors and decides when to start the compressor or turn on the fan. If a failure occurs in the electronics, the firmware is “buggy” or certain elements on the board burn out, it can send incorrect commands to the actuators.
As a result, the refrigerator can ignore the readings of the temperature sensors in the positive chamber and continue cooling. Often such problems arise after power surges or thunderstorms. Symptoms can be floating: today the refrigerator freezes normally, but tomorrow it goes into negative mode again. Sometimes rebooting the system helps, but more often a flashing or replacement of the module is required.
Diagnostics of the electronic unit requires special knowledge and equipment. You can only visually inspect the board yourself for blackening or swollen capacitors. If you notice that the indicators on the panel are behaving strangely (blinking, showing incorrect values), this is a direct path to checking the “brains” of your unit.
The influence of the operating mode and user settings
Before sounding the alarm and calling a technician, it is worth eliminating the human factor. Often, users accidentally switch the refrigerator to "Super Freeze" (Super Freeze), which is designed for quick freezing of large quantities of food in the freezer. In this mode, the compressor operates at maximum power without turning off, which inevitably leads to a decrease in temperature in the main compartment.
An incorrect setting of the temperature regime may also be the cause. If the mechanical type control is turned to maximum (usually indicated by the number 6 or 7, or the word “Max”), the refrigerator will strive to achieve extremely low temperatures in all chambers. In the summer, when the ambient temperature is high, this setting forces the equipment to work at its limit.
Another important aspect is the loading density. If you put a large amount of warm food in the refrigerator or, conversely, completely clogged the chamber to the point where air does not circulate, this may disrupt the operation algorithms. The refrigerator will “think” that the temperature does not drop and will continue to freeze.
☑️ Checking the settings before calling a technician
Mechanical damage and wear of seals
It would seem that a loose door fit should lead to an increase in temperature, but in some cases this causes the opposite effect. If warm, moist air constantly enters through the gap in the seal, excess frost will form on the evaporator. The system No Frost may not be able to cope with the utilization of such an amount of ice; it builds up on the evaporator and begins to interfere with the normal operation of the damper or sensors.
In addition, the constant flow of heat causes the compressor to work longer, which again leads to general overcooling of the system. Wear of rubber seals is a natural process, especially if the door is slammed or foreign objects are pressed into it. You can check the tightness with a simple test with a sheet of paper: hold the sheet with a door and try to pull it out. If it is pulled out without effort, the seal requires replacement or adjustment of the hinges.
It is also worth checking whether the door itself is warped. Over time, the hinges may become loose and the door will begin to come loose at the top or bottom. This disrupts the geometry of the fit and creates gaps through which heat exchange occurs, destabilizing the operation of the entire system.
⚠️ Attention: When checking the seals, use only a soft cloth and warm soapy water. Aggressive chemicals can corrode the rubber, making it hard and brittle, which will finally break the seal of the chamber.
Frequently asked questions and answers (FAQ)
Can I continue to use the refrigerator if it freezes food?
Short-term use is possible, but not recommended. Constant operation of the compressor without rest leads to its overheating and eventual failure, which will require much more expensive repairs. In addition, products in such conditions lose their properties.
Why does water freeze only on the top shelf?
The physics of the process is such that cold air is heavier than warm air and falls down, but in refrigerators with forced circulation (No Frost) the flows can be directed differently. Often the upper shelves are located closer to the source of cold or a sensor that incorrectly reads the temperature in this zone.
How much does it cost to replace a thermostat?
The cost consists of the price of the part itself and the work of the technician. For mechanical thermostats, the price is usually affordable, while electronic sensors and their replacement in complex models can be more expensive. The exact amount can only be announced after diagnosing a specific model.
Will defrosting help if the refrigerator is freezing in the plus chamber?
Defrosting for 24 hours can help if the problem is caused by frozen channels or a temporary failure of the electronics. However, if the reason is a broken thermostat, a freon leak or a malfunction of the module, after turning on the problem will return within a few hours or days.