The situation when food suddenly freezes in the refrigerator compartment, and a “coat” of ice appears on the walls, familiar to many owners of household appliances. This is not just an inconvenience leading to spoilage of fresh vegetables and fruits, but also an alarming signal that a serious malfunction has occurred in the operation of the unit. If you notice that the refrigerator began to freeze very much, you cannot ignore this, since constant operation of the compressor for wear and tear can lead to expensive repairs or complete replacement of the unit.
Excessive cooling is often accompanied by a continuous humming of the motor, which does not go into rest mode. In some cases, ice may block the door or form in unexpected places, such as around the thermostat or on the back of the chamber. Understanding the nature of this phenomenon is the first step to restoring normal temperature conditions and saving food supplies.
In this article we will analyze in detail the mechanical and electronic causes of the malfunction, methods of self-diagnosis, and cases when you cannot do without calling a technician. It is important to act quickly, but without panic, sequentially checking each component of the system.
Thermostat malfunctions as the main cause
The most likely culprit that refrigerator began to turn into a freezer is a failed thermostat. This small device is responsible for monitoring the temperature inside the chamber and sending a signal to the compressor to turn on or off. If its contacts stick in the closed position or the sensitive tube with refrigerant bursts, the unit “thinks” that the chamber is warm and continues to freeze indefinitely.
In older models, such as Atlant or Biryusathermostats mechanical and often fail due to natural wear and tear. In modern devices, for example Liebherr or Bosch, the control function is performed by an electronic sensor, which can also transmit distorted data to the control board. In both cases, the system loses adequate feedback from the environment.
⚠️ Attention: If you plan to replace the thermostat yourself, be sure to make sure that the new device has exactly the same markings and temperature range as the old one. Installing an unsuitable model will lead to incorrect operation of the entire system.
To check a mechanical thermostat, it is often necessary to test it with a multimeter or visually inspect it for corrosion and damage to the capillary tube. Electronic sensors are checked by measuring their resistance, which should change depending on the temperature.
How to check a thermostat without instruments?
There is a popular method: if you remove the thermostat and lower its sensitive tube into cold water (about 0°C), a working instrument should click and break the circuit. If there is no click, the part is faulty.
Failures in the operation of the electronic control module
In modern units with a system No Frost or electronic control, the central processor is responsible for all processes. If the refrigerator is very cold, this may be a consequence of a “glitch” of the control board or the failure of one of its elements, for example, a triac that controls the compressor.
Electronics may behave inappropriately after voltage surges in the network or moisture on the contacts. In such cases, the unit can ignore the temperature sensor readings and operate in maximum power mode. Diagnosis of such faults is complex and requires special knowledge and equipment.
Often the problem lies not in the “brain” of the refrigerator itself, but in oxidized contacts or damaged wires going to the sensors. Poor wiring leads to signal loss, and the module defaults to an active cooling cycle.
- 🔌 Check the integrity of the wires leading from the board to the temperature sensors.
- 💧 Inspect the board for swollen capacitors or signs of corrosion.
- ⚡ Ensure that the mains voltage is stable and appropriate normal.
Problems with the seal and seal of the chamber
Paradoxically, the cause of ice formation and excessive cold can be a violation of the door seal. If the rubber seal is worn out, dirty or deformed, warm, moist air from the room constantly enters the chamber.
Moisture from this air condenses on the cold walls and freezes, forming a thick crust of ice. The temperature sensor, “seeing” this ice, may mistakenly assume that the temperature is normal, or, conversely, the system No Frost will work in enhanced mode, trying to dry the air, which leads to freezing.
You can check the tightness using a simple sheet of paper. Clamp the sheet with the door around the perimeter: if it pulls out easily and without resistance, it means that the seal does not fit in this place. Also pay attention to the door hinges - if they are skewed, tight closure cannot be achieved.
☑️ Diagnosis of the seal
Incorrect operation of the defrost system (for No Frost)
In units with The system No Frost responsible for removing moisture and defrosting the evaporator is a special timer or electronic module, a heating element and a defrost sensor. If one of these elements fails, the evaporator becomes overgrown with ice, which blocks the air circulation channels.
As a result, cold air stops circulating normally through the chamber, and the fan begins to drive ice chips or work with overload. This can lead to local overcooling of zones or, conversely, to an increase in temperature, but most often the system begins to work incorrectly, trying to compensate for losses.
A common cause is a burnt-out defrost heating element or a stuck relay. In this case, the refrigerator operates in constant cooling mode, since the defrosting cycle simply does not start. The ice builds up, and after a while the food in the upper part of the chamber begins to freeze.
⚠️ Attention: Do not try to break off the ice with a knife or sharp objects. This can damage the evaporator, resulting in an immediate freon leak and costly repairs.
Refrigerant Leaks and Compressor Performance
Although a freon leak is more often associated with insufficient cooling, in some cases it can cause strange effects, including the formation of ice dams. If the refrigerant becomes critically low, the compressor may run non-stop, trying to gain temperature, but the cooling efficiency drops unevenly.
An ice build-up may form at the leak site or in front of it. This occurs due to changes in pressure in the circuit. If you see that the rear grille of the refrigerator is cold or only partially covered with frost, and the compressor hums continuously, this is a sure sign of problems with the circuit.
Prolonged operation of the compressor in this mode leads to its overheating and eventual combustion of the windings. Therefore, if you notice signs of a leak (oily stains, a strange smell, continuous operation of the motor), it is better to stop using it.
Influence of settings and external factors
Before disassembling the equipment, it is worth checking trivial things. Perhaps one of the household members accidentally switched the temperature regulator to Super Freeze or “Maximum cooling” mode. In this mode, the refrigerator operates at its maximum capacity.
The location of the unit also affects the operation. If it is placed too close to a wall, a radiator, or in direct sunlight, the cooling system works under increased load. Incorrect loading of food (closing the air ducts) also disrupts circulation.
Check the settings on the display (if there is one) or the position of the thermostat knob. Make sure the Holiday or Quick Freeze mode is turned off. Sometimes the problem is solved by simply resetting the settings to factory settings.
Table: Comparison of symptoms and probable causes
For ease of diagnosis, we have compiled a table that will help compare the observed symptoms with the most likely malfunctions.
| Symptom | Probable cause | Difficulty of repair | Required actions |
|---|---|---|---|
| Compressor does not turn off, ice on the back wall | Thermostat is faulty | Low | Replacing the thermostat |
| Ice only in the freezer, warm in the refrigerator compartment | Clogged the defrost channel or the heating element is faulty | Average | Defrost, checking the heating element |
| The refrigerator hums, but does not freeze or freezes weakly | Freon leak or breakdown compressor | High | Call a technician |
| The ice freezes unevenly, the food at the door withers | The door seal is damaged | Low | Replacing or cleaning the seal |
| Indicators are flashing, chaotic temperature changes | Electronics or sensors failure | High | Diagnostics of the control module |
When you need to call a technician
Not all faults can be eliminated yourself. If the problem lies in a sealed circuit (freon leak, clogged capillary tube) or the compressor has burned out, special equipment is required: a vacuum pump, pressure gauges, a burner and a supply of refrigerant.
Also, you should not go inside complex electronics without the appropriate qualifications. An attempt to “resolder” the control board can lead to a short circuit and final failure of the unit. If after defrosting and checking the settings the problem persists, call the specialists.
Professional repair guarantees not only the elimination of the current malfunction, but also checking adjacent components, which will prevent the situation from reoccurring in the future. Remember that timely repairs are cheaper than buying a new refrigerator.
⚠️ Attention: Independent intervention in the refrigerant (freon) circulation system is dangerous and can lead to injury or property damage. Entrust this work to certified specialists.
Frequently asked questions (FAQ)
Why does bottled water freeze in the refrigerator, although the thermostat is set to minimum?
Most likely, the thermostat is faulty and does not open the circuit, or its sensitive tube has lost tightness. It is also possible that the relay contacts on the control board may become stuck. The thermostat needs to be replaced or the module repaired.
Is it possible to operate the refrigerator if it gets very cold?
For a short time - yes, but this is harmful for the compressor, which works without rest. Food in the refrigerator compartment will spoil. It is better to eliminate the cause or at least defrost the unit.
How often do you need to defrost a No Frost refrigerator?
The No Frost system does not require regular defrosting to remove ice, but hygienic washing and complete shutdown for drying are recommended 1-2 times a year. This will extend the life of the equipment.
Why, after defrosting, did the refrigerator start to freeze very hard again after a couple of days?
This indicates a system malfunction, and not a temporary accumulation of moisture. The temperature sensor or thermostat has probably failed, or the defrost system has malfunctioned. Diagnostics are required.