The situation when the refrigerator is unstable, causing panic among the owners, occurs quite often. Owners notice that food in one part of the chamber freezes through, and in the other begins to deteriorate from the heat. This behavior of the equipment indicates malfunctions in the temperature control system or problems with the refrigerant.
Such symptoms cannot be ignored, since unstable operation the compressor leads to its rapid wear. In addition, constant temperature changes are detrimental to the safety of food. In this article, we will analyze in detail why the unit behaves unpredictably and how to diagnose a breakdown before the technician arrives.
Often the reason lies in small things that are easy to fix on your own, but sometimes serious repairs are required. Understanding the principles of operation refrigeration circuit will help you not to overpay for diagnosing simple faults. Let's look at the main factors influencing the refrigeration cycle.
Malfunctions of the thermostat and temperature sensors
One of the most common reasons why a refrigerator either freezes or not is failure thermostat. This mechanical or electronic component is responsible for turning the motor-compressor on and off when the set temperature values are reached. If the contacts inside the device stick or oxidize, the start signal may not arrive on time.
In models with the system No Frost air sensors are responsible for temperature control. They are located at different points in the chamber and evaporator. If one of the sensors malfunctions electronic module receives distorted data about the climate inside the chamber. As a result, the equipment may not turn on for a long time, thinking that there is already cold, or work without stopping.
Diagnostics of the thermostat often requires testing the contacts with a multimeter. If the rod does not make a characteristic click when the temperature changes, the device is most likely faulty. Replacing this element usually does not require complex equipment and is done quite quickly.
Problems with the compressor and start relay
The heart of any refrigerator is the compressor, and it is its operation that is often disrupted with the symptoms described. If you hear a buzzing sound, a clicking sound, and then silence, the problem is probably in starting relay. This small element supplies a starting impulse to the motor windings. If it burns out or is mechanically damaged, the compressor cannot start, although voltage is supplied to it.
The motor itself can also be a source of problems. Wear of internal mechanical parts or interturn short circuit of windings leads to the fact that the unit operates jerkily. It can turn on, work for several minutes and turn off due to thermal protection, without reaching the desired evaporation temperature. It is important to listen to the sounds that the equipment makes. A steady hum followed by silence is the norm. But if you hear knocking, grinding, or an excessively loud hum when you try to start, this is a warning sign. In such cases, operation evaporation temperature.
It is important to listen to the sounds that the equipment makes. A steady hum followed by silence is the norm. But if you hear knocking, grinding, or an excessively loud hum when you try to start, this is a warning sign. In such cases, operation of the refrigeration unit must be stopped until the reasons are clarified.
What is compressor thermal protection?
This is a special device that opens the electrical circuit if the temperature of the motor housing becomes critically high. This prevents windings from burning out and causing fire. If the compressor often turns off due to thermal protection, it means that it is overheating due to overload or poor ventilation.
Incorrect settings and operating errors
Before looking for breakdowns, it is worth eliminating the human factor. Often, users accidentally touch the temperature regulator, switching it to extreme modes. If the mode is set super freezing, the refrigerator will work continuously, trying to reach unattainable values, and then may go into a long rest due to a system error.
The loading density of the chambers also plays an important role. If you put a large amount of warm food into a freshly defrosted refrigerator, it will wear out. However, after reaching cold, it may not turn on for too long, since heat capacity the products are large, and they give off heat for a long time to the air that has already cooled down around the sensor.
Check the position of the door. A loose seal or skewed door leaf leads to a constant flow of warm air. The compressor tries to compensate for the heat, but due to the sensor that “sees” local heat at the door, the operation cycle is disrupted. As a result, food can freeze in the depths of the chamber, and melt at the door.
Freon leak and capillary tube clogged
The refrigerant circulation system is a closed circuit, and a violation of its tightness leads to serious failures. If a microcrack has formed in the system, freon begins to gradually evaporate. It becomes insufficient for effective heat exchange. The compressor turns on, tries to build up pressure, but due to a lack of gas, the temperature does not drop, and the motor turns off due to a timer or overheating.
Another common problem is clogged capillary tube. Not only gas, but also oil circulates in the system, and oxidation products or moisture can also enter. Over time, a plug forms in the narrow channel of the capillary. The pressure in front of the plug increases, the compressor is overloaded, but after the evaporator there is no cold. Then the system can shut down, the plug will partially dissolve, and the cycle will repeat.
A symptom of a leak is often a hot condenser (grid at the back) with a cold inner chamber. If there is a blockage, the condenser may only be half hot or at the point of the blockage. It is difficult to eliminate these malfunctions on your own, as it requires evacuating the system filling with gas.
☑️ Signs of a freon leak
Failures in the defrost system (for No Frost)
In refrigerators with an automatic defrost system, a whole complex of devices is responsible for removing moisture: Evaporator heating element, a defrost sensor and a timer (or electronic module). If any of these elements fails, a “coat” of ice begins to grow on the evaporator.
Ice blocks the ventilation ducts, and cold air stops flowing into the chamber. Sensors detect the absence of cold and command the compressor to work continuously. However, since the channels are clogged with ice, the temperature does not drop. At some point, the system may go into emergency mode or the ice will partially melt, and the cold will appear again for a short time.
It is often the one that “does not see” the ice and does not turn on the heating that fails, or the heating element that simply burns out. Visually, this is manifested by ice on the back wall inside the freezer, which can be seen if you remove the plastic panel. defrost sensor, which “does not see” the ice and does not turn on the heating, or a heating element that simply burns out. This is visually manifested by ice on the back wall inside the freezer, which can be seen if you remove the plastic panel.
⚠️ Attention: If you notice ice freezing in the No Frost chamber, do not try to break it off with a knife or sharp objects. Damage to the evaporator will lead to an immediate leak of freon and expensive repairs with replacement of the foamed evaporator.
Diagnostics and table of symptoms
To accurately determine the cause of unstable operation, it is important to compare the symptoms. Below is a table that will help you navigate the nature of the malfunction. Remember that an accurate diagnosis can only be made by a specialist using a pressure manifold and a tester.
| Symptom | Probable cause | The nature of the compressor operation |
|---|---|---|
| There is cold, but disappears after a while | The thermostat or sensor is faulty | It turns on rarely or doesn’t turn on at all |
| Buzzes, clicks and turns off | The starting relay has burned out | Short attempts to start (5-10 seconds) |
| Works constantly, no cold | Freon leak or clogged | Works without stopping or with short pauses |
| Ice in the freezer, warm in the refrigerator | Malfunction of the defrost system | Works in enhanced mode |
Frequently asked questions and answers (FAQ)
Can a refrigerator stop freezing due to a power surge?
Yes, voltage surges can damage the electronic control module or pierce the compressor windings. Modern models often have protection that blocks startup until the voltage stabilizes. If the surge was strong, it could burn varistor or other elements of the board.
Why does the refrigerator work unstably after defrosting?
If you defrosted the equipment by violating the instructions (for example, by chipping off ice), you could damage the defrosting system. It is also possible that moisture has gotten into the electrical contacts. Let the refrigerator stand turned off for several hours so that the moisture evaporates, and try turning it on again.
Does the temperature in the room affect the operation of the refrigerator?
Absolutely. If the room is too hot (above +30°C), the compressor will work almost without interruption, trying to compensate for the heat gain. If it is too cold (below +10°C), the oil in the compressor may thicken and the freon may stop evaporating correctly, which will lead to malfunctions in the operating cycle.
What to do if the refrigerator turns on for 1 minute and turns off?
This is a classic sign of a malfunction of the start relay or the compressor itself (jamming). The relay needs to be checked. If everything is fine, the problem is most likely in the mechanical part of the motor and it will need to be replaced.
⚠️ Attention: Refrigerant characteristics and safety requirements may vary depending on the model and year of manufacture. Always check the manufacturer's technical documentation before carrying out work related to the cooling system.
How to extend the life of the compressor?
Ensure good ventilation of the rear wall of the refrigerator. Move at least 10 cm away from the wall. Dust on the condenser (black grille at the back) acts like a blanket, interfering with heat transfer, which causes the motor to work with overload. Vacuum the grille every six months.