The situation when household appliances begin to work incorrectly always causes concern among owners. It is especially unpleasant to discover what the refrigerator is very cold inside the chambers, turning fresh vegetables into ice blocks, and milk into a solid block. This phenomenon not only spoils the taste of the food, but may also indicate serious malfunctions in the cooling system. Understanding the reasons for this process is the first step to restoring a normal microclimate in the device.
Excessive cooling often comes as a surprise to users who are accustomed to the stable operation of the unit. This may occur suddenly or develop gradually, requiring human intervention. In most cases, the problem lies in the imbalance between cold production and its regulation. If you notice that frost is forming on the shelves, and products are freezing even with standard settings, you need to conduct a thorough diagnosis.
In this article, we will analyze in detail the mechanics of the refrigeration circuit and find out why the system may produce excess cold. We will consider both simple operating errors that you can correct yourself, and complex technical malfunctions that require the participation of a specialist. A competent approach will allow you to save time and money, as well as keep food supplies in proper form.
Principles of operation of the cooling and thermoregulation system
To understand why the device begins to freeze more than expected, you need to briefly brush up on the basic principles of its operation. The basis of the process is the circulation of refrigerant in a closed circuit, which, evaporating in the evaporator, removes heat from the chambers. The key element here is thermostat or the electronic control module, which gives the command to the compressor to turn on or off. If this mechanism fails, the cooling cycle is not interrupted in time.
In modern models with the system No Frost the situation is complicated by the presence of fans and additional sensors. Here, cold air is forced into the chambers, and if the damper that regulates the flow is stuck open, the temperature will drop uncontrollably. The compressor may work in overdrive, trying to achieve impossible values if the temperature sensor is “lying” or has lost contact.
How does a temperature sensor work?
The sensor (thermistor) changes its electrical resistance depending on the ambient temperature. The electronic module reads these changes and, comparing them with the set parameters, makes a decision to start or stop the compressor. If the sensor resistance is outside the normal range, the module may mistakenly assume that the chamber is too warm.
It is important to note that different zones inside the refrigerator have different temperatures. Usually the coldest place is near the back wall or in the cold air supply area. If food freezes right there, this may be normal, but if ice covers the entire shelf, this is a clear sign of malfunctions adjustments.
Errors in the settings and operation of equipment
Before sounding the alarm and calling a repair team, you should exclude the human factor. Often, users accidentally change operating modes or place products incorrectly. For example, activating the function Super Freeze (Super Freeze) or Fast Cool switches the compressor to continuous operation mode. If you forget to turn off this option, the refrigerator will freeze until the emergency protection works or the electricity runs out.
It is also worth paying attention to the loading density of the chambers. If you have just placed a large amount of warm food inside or, conversely, have packed the shelves too tightly, the natural or forced circulation of air masses is disrupted. In this case, the temperature sensor may not have time to read real indicators, which leads to freezing.
Another common reason is incorrect temperature setting. Some models allow you to set the temperature to the nearest degree. If the value is set to a minimum (for example, +1...+2°C), then near the cooling zone the water will turn into ice. It is recommended to set average values, usually +3...+5°C, and check the result after a day.
☑️ Checking the settings before repair
It is also worth checking the tightness of the seals. If the rubber on the door is worn out or dirty, warm air from the room constantly enters the chamber. Reacting to this, the automation forces the compressor to work without stopping, which ultimately leads to severe hypothermia of the internal space.
Malfunctions of the thermostat and temperature sensors
One of the most common technical reasons why the refrigerator freezes inside is the failure of the thermostat. In mechanical models, this device is a relay with a capillary tube that is filled with a temperature-sensitive gas. When cooled, the gas compresses and the contacts open, turning off the motor. If a gas leak occurs or the contacts stick, the circuit will not break and the cooling will continue indefinitely.
In electronically controlled units, temperature sensors (thermistors) are responsible for this process. Their resistance varies depending on degrees Celsius. Over time, the sensor may “float”, giving incorrect readings to the control module. For example, at a real temperature of +2°C, it can signal that the chamber is +10°C, forcing the system to continue working.
⚠️ Attention: Diagnostics of sensors requires special equipment (multimeter). Do not try to check the continuity of the circuit under voltage, this may lead to burning of the electronic control module.
Replacing a thermostat or sensor is a relatively simple procedure, but requires disassembling part of the structure. In mechanical models, you will need to get to the place where the capillary tube is attached, usually it is located in the chamber or on the back wall. In electronic ones, find and replace the sensor itself, often hidden behind plastic panels.
Problems with freon and compressor
It would seem that a refrigerant leak should lead to a lack of cold, but in some cases the opposite effect is observed. If a microcrack develops in the system and freon begins to leak, the compressor may work longer and harder in an attempt to compensate for the loss of efficiency. This leads to the fact that the evaporator is covered with a “fur coat”, and in the refrigeration chamber the temperature drops below normal until the compressor burns out from overload.
It is also worth mentioning clogged capillary tube. If an ice or technical blockage forms in the refrigerant circulation system, the pressure in the circuit is disrupted. This can cause uneven cooling: the freezer will be extremely cold, but the refrigerator compartment will be warm, or the entire system will enter an incorrect operating mode.
The compressor is the “heart” of the refrigerator. If its valves are worn out, it can circulate freon with insufficient efficiency, but at the same time consume a lot of energy and create excess pressure in one part of the circuit. In such cases, a specific metallic knock or hum is often heard.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The compressor runs non-stop | The thermostat is faulty or Freon leak | Checking sensors, searching for leaks |
| Ice only on the back wall | Faulty defrost or damper | Checking the defrost heating element and timer |
| Food is frozen at the back wall | Improper placement of food | Move food away from the wall |
| The refrigerator is noisy and freezes | Problems with the compressor | Motor diagnostics by a master |
Failures in the defrost system (for No Frost models)
In refrigerators with the system No Frost the condition of the evaporator defrost system is critically important. Periodically, usually every 8-12 hours, the heating element (heating element) should be turned on, which melts the ice on the evaporator. If this process is disrupted, ice builds up in a thick layer and blocks the air supply channels.
When the air ducts are clogged with ice, cold air cannot circulate normally. As a result, the fan begins to circulate air locally, creating zones of abnormally low temperature near the outlet, while other corners of the chamber may be warm. The temperature sensor, being in the overcooling zone, may incorrectly read the data.
The main elements that fail in the defrost system:
- ❄️ defrost heating element - burns out and stops heating, the ice does not melt.
- ❄️ Defrost sensor —does not give a command to turn the heating on or off.
- ❄️ Timer or control module —does not give a signal to start the defrost cycle.
For diagnostics it is necessary to defrost the refrigerator completely (at least for 24 hours with doors open). If, after turning on, the problem with freezing disappeared for several days and then returned, it means that the defrosting system is not working.
When you need to call a technician: diagnostics and repair
There are a number of signs in which independent repair is not only ineffective, but also dangerous. If you have checked the settings, ensured the integrity of the seals and defrosted, but the refrigerator continues to operate incorrectly, professional intervention is required. This is especially true for work related to the refrigerant and the electrical part.
A master is needed if:
- 🛠️ The compressor operates around the clock, without turning off, and gets very hot.
- 🛠️ Visible on the tubes in the compressor area or on the back wall oily coating (a sign of leakage).
- 🛠️ Electronics generate error codes that are not reset after a reboot.
⚠️ Attention: Opening the freon circulation circuit yourself is strictly prohibited. This requires a license, special tools and knowledge. In addition, modern refrigerants can be a fire hazard if handled incorrectly.
A specialist will measure the pressure in the system, check the resistance of the compressor windings and the integrity of electrical circuits using professional instruments. Only after an accurate diagnosis will repair or replace components be made. Remember that trying to save on calling a technician in case of complex breakdowns often leads to the need to buy a new refrigerator.
Prevention and proper care of the refrigerator
To avoid situations when the refrigerator begins to freeze food excessively, it is important to follow the operating rules. Regularly check the condition of the rubber seals on the doors: they should be clean and elastic. Once every six months, it is recommended to wash them with warm water and soapy water.
Do not place hot or warm foods inside the chamber. This creates extra load on the compressor and upsets the temperature balance. Also make sure that the ventilation holes inside the chamber are not blocked by pots or bags. Free air circulation is the key to stable temperature.
Once a year, it is advisable to carry out preventive defrosting (even for No Frost systems), disconnecting the device from the network for a day. This will allow you to remove micro-ice in hidden places and give the equipment a rest. Following these simple rules will extend the life of your refrigerator and maintain the quality of the products.
Why does the refrigerator freeze even if the thermostat is working?
The reason may lie in sticking contacts of the compressor relay itself or a malfunction of the electronic control module, which sends incorrect signals to turn on the motor. It is also possible for the temperature control damper to malfunction in models with two circuits.
Is it possible to regulate the temperature in a running refrigerator?
Mechanical thermostats can be adjusted on the go, but it is better to change the electronic settings when the refrigerator is in operation. Sudden changes in settings can cause stress to the compressor.
What to do if, after defrosting, the refrigerator starts to freeze very hard again?
This is a sure sign of a malfunction of the defrost system (heating element, sensor, timer) or a freon leak. It is necessary to call a technician for diagnosis, since the problem is of a technical nature.
Does the location of the refrigerator affect the severity of the frost?
Yes, if the refrigerator is too close to the wall or heat source (battery, stove), the heat exchange of the condenser is disrupted. The compressor begins to work with overload, which can lead to malfunctions in the temperature regime.
How to understand that there is little freon in the refrigerator?
Signs: the compressor works constantly, there is no cold or it is weak, the condenser (grid at the back) is only partially warm or cold, sometimes hissing or gurgling is heard.