The situation when household appliances begin to work incorrectly always causes concern for the owner. Especially when it comes to maintaining a supply of food. If you notice that ice is freezing in the refrigerator where it should not be, or food is turning into ice, this is a direct signal of a malfunction in the temperature control system.
Why The refrigerator is very cold? The answer lies in the imbalance between the production of cold and signals about its sufficiency. The compressor continues to circulate refrigerant through the system without receiving a command to stop. This leads to excessive energy consumption and damage to the contents of the shelves. In this article, we will analyze in detail the main components that may fail, and the algorithm of actions for self-diagnosis.
You should not ignore the first symptoms. Prolonged operation in the “superfreeze” mode can lead to failure of the compressor itself due to overload. Understanding the operating principles of thermostat and sensors will help you quickly determine whether you need to call a technician or the problem can be solved yourself.
Malfunction of the thermostat (thermostat)
The most likely reason that the refrigerator is very cold, lies in the thermostat. This mechanical or electronic component is responsible for opening the electrical circuit of the compressor when the set temperature is reached. If the contacts inside the thermostat are “stuck” in the closed position, the motor will work endlessly, pumping in cold.
In older models with mechanical control, the breakdown is often associated with loss of tightness of the bellows - a corrugated tube filled with freon. When the freon inside the tube evaporates, the pressure drops and the contacts stop opening. In electronic models, the control board itself or oxidized contacts may fail.
To check the mechanical thermostat in models Indesit or Atlant often it is enough to remove it and place the sensor tube in a container with cold water. If there is no click, the part must be replaced. This is a consumable material that lasts an average of 5-7 years.
How to distinguish a mechanical thermostat from an electronic one?
A mechanical thermostat has a round knob with numbers from 1 to 7 (or Min/Max) and often protrudes into the chamber. Electronic control is usually implemented through a display on the outer door or a hidden panel with buttons where the temperature is set in degrees Celsius.
It is important to understand that a faulty thermostat is not just an inconvenience. This is a risk of the evaporator defrosting in the future as the defrost system may not be able to handle the volume of ice. If your unit works without interruptions, and an “iceberg” has formed inside, in 80% of cases this unit is to blame.
⚠️ Attention: When replacing the thermostat, it is extremely important not to bend or damage the capillary tube. Even a microscopic crack will cause freon to leak from the thermostat circuit, and it will stop working correctly immediately after installation.
Problems with the temperature sensor (for No Frost models)
Modern refrigerators operating on the system No Frostare controlled by complex electronics. Air sensors (thermistors) are responsible for temperature control here. If such a sensor “lies” and transmits a signal to the control module that it is warm in the chamber, the compressor will work for wear.
Often the problem lies not in the sensor itself, but in the oxidation of the contacts at the point where it is connected to the wiring. A humid environment inside the chamber promotes corrosion. The resistance of the circuit changes, and electronics receives distorted data. As a result, the refrigerator freezes intensely, trying to achieve a non-existent ideal.
Diagnostics of the sensor is carried out using a multimeter. It is necessary to measure its resistance at room temperature and compare the readings with a table of values for a specific model. If the resistance approaches infinity or zero, the element is faulty. Replacing the sensor is a quick procedure, but requires care when disassembling plastic panels.
Another cause of failures in electronics can be a power surge. Pulse noise can “sear” the input circuits of the control module, which is why it stops correctly reading sensor readings. In such cases, it may be necessary to reflash or replace the board.
Failure of the air damper
In two-chamber refrigerators with a system No Frost cold is generated in the freezer compartment, and is supplied to the refrigeration compartment through a special channel. The air flow is regulated by a damper. If the damper mechanism is stuck in the open position, cold air freely enters the upper chamber.
This leads to the fact that the products on the shelves located closer to the air supply duct freeze. Vegetables in the drawers can stay fresh while the milk on the top shelf turns to stone. This is a classic sign of a malfunction air duct or damper drive.
The damper drive can be mechanical (thermal) or electrical. In the first case, a bellows is used, which expands or contracts with temperature, opening or closing the damper. In the second there is a small motor controlled by the board. The check begins with a visual inspection: whether ice or a foreign object is interfering with movement.
If the damper is electric, listen for a faint humming sound when the compressor starts. Its absence may indicate a burnt-out motor or a broken gear inside the plastic housing. Replacement of the entire damper assembly is often more practical than repairing individual components.
Freon leakage and compressor operation
Paradoxically, but sometimes the refrigerator gets very cold precisely because of a lack of refrigerant. When freon leaks, the pressure in the system drops. The compressor, trying to compensate for the lack of cold, runs continuously without turning off. As a result, in the evaporator (where freon boils) the temperature drops to extreme values.
Ice in this case grows unevenly. You can often observe a “snow coat” only at the beginning of the evaporator or, conversely, its complete icing when the chamber is warm. This is a dangerous operating mode, as the compressor overheats and can burn out.
Detecting a leak visually is difficult, since freon is colorless and odorless. An indirect sign may be swelling of the back wall of the refrigerator (in the place of the foamed evaporator) or oily spots on the tubing. An accurate diagnosis requires a technician with a leak detector.
| Symptom | Probable cause | Nature of freezing |
|---|---|---|
| The compressor hums without stopping | Faulty thermostat | Uniform ice throughout the chamber |
| Freezes only at the back wall | Failure of the damper or sensor | Local "iceberg" near the channel |
| Refrigerator warm, but freezing | Freon leak | Ice only at the beginning of the circuit |
| Sparks inside or electronics failures | Problems with the control board | Chaotic on/off |
⚠️ Attention: If you suspect a freon leak, under no circumstances try to simply add gas. Without finding and fixing the leak (soldering), the problem will return in a few days or weeks. In addition, different types of freon (R134a, R600a) do not mix.
Improper operation and placement
Before committing a breakdown, it is worth eliminating the human factor. Sometimes the refrigerator is very cold due to a banal violation of operating rules. Check the position of the temperature regulator. Perhaps one of the household members accidentally turned the knob to the “Max” or “Super Freeze” position.
It is important to consider the location of the unit. If the refrigerator is too close to the wall or heating appliances, the air circulation around the condenser is disrupted. The compressor overheats and operates under increased load, which can lead to temperature failures.
Load density also plays a role. An empty refrigerator freezes faster, since there are fewer “heat-intensive” products there that stabilize the temperature. And vice versa, if the products lie close to the back wall, they can freeze to it, creating the illusion of excessive cold in the entire chamber.
☑️ Check before calling a specialist
Check the integrity of the rubber seal on the door. If it does not fit tightly, warm air constantly flows inside. Sensors detect an increase in temperature and give a command for enhanced freezing. As a result, a lot of ice forms inside, and the compressor hums incessantly.
Diagnostics and troubleshooting methods
If external causes are excluded, you will have to move on to technical diagnostics. First, turn off the power to the device. Visually inspect the interior walls for ice. If it is a system Direct Cool (crying evaporator), the ice should melt in defrost cycles. If the ice lies “for centuries”, the defrosting system does not work or the thermostat does not give a command to stop.
To check the thermostat in mechanical models, you can use the exclusion method. Close the thermostat contacts directly (observing safety precautions!). If after this the compressor starts working, it means that the circuit is intact, and the problem is most likely in the thermostat itself, which does not open the circuit. If the compressor is silent, the problem is in the motor or start relay.
In electronic models, resetting the error often helps. Unplug the refrigerator for 15-20 minutes. This will reboot the control module. If, after some time after switching on, the operating mode returns to normal, a single electronic failure may have occurred. If the situation repeats, the sensors or board need to be replaced.
When you need to call a specialist
There are a number of situations when self-repair is not only useless, but also dangerous. If you hear the hiss of escaping gas, smell burning wiring, or see sparking, immediately turn off the appliance and call a professional. A technician is also needed to replace the compressor or repair leaks in the foamed part of the housing.
Diagnosing electronic boards is difficult. Without an oscilloscope and a circuit, it is almost impossible to determine a burnt element on the control board Bosch or LG . Incorrectly replacing entire components can lead to financial losses.
Remember that the refrigerator warranty may be void if you independently open the seals or violate the integrity of the factory connections. If the unit is new, it is better to immediately contact an authorized service center.
Why does the refrigerator freeze even if the thermostat is working?
If the thermostat is working, the reason may be a “stuck” compressor start relay that does not open the start winding, or a malfunction of the electronic control module that sends incorrect signals. A distortion in the defrosting system is also possible.
Is it possible to regulate the temperature in the refrigerator with additional thermometers?
The use of external thermometers is only useful for control. They cannot control the operation of the compressor. If you see -10°C in the refrigerator compartment on the external thermometer, it means that the control system is broken, and the thermometer is only stating a fact.
How often do you need to defrost the refrigerator if it starts to get very cold?
If the refrigerator starts to get very cold, complete defrosting (at least 24 hours with the doors open) is necessary before any diagnostics. Ice distorts sensor readings and interferes with the operation of the dampers. Without defrosting, accurate diagnosis is impossible.
Does the amount of food affect the freezing strength?
Yes, it does. An empty refrigerator gets colder faster and turns on more often. A full chamber stabilizes the temperature. However, if the refrigerator freezes to the point of being “stony”, the amount of food will no longer save you - adjustment or repair is needed.
Is it dangerous to continue to use a refrigerator that freezes too much?
Short-term use is acceptable, but undesirable. Long-term operation in continuous freezing mode leads to overheating and breakdown of the compressor, as well as spoilage of food and increased energy bills.