A sudden stop of the refrigerator or the appearance of a loud humming often indicates a critical malfunction of the heart of the unit - compressor. It is this unit that circulates the refrigerant, creating the necessary cold in the chambers. When the motor stops starting or works intermittently, food begins to deteriorate, and the owner is faced with the need for urgent repairs or expensive replacement.
Understanding why the compressor in the refrigerator breaks down helps prevent a disaster or minimize damage at the first symptoms. The reasons may be trivial, for example, a power surge, or complex, associated with wear and tear of internal mechanical parts. In this article, we will analyze in detail the main risk factors, diagnose the signs of impending failure and discuss whether it is worth trying to restore the old unit.
Ignoring primary signs, such as overheating of the housing or unusual noise, often leads to complete jamming of the motor shaft. Inverter models and classic linear compressors have different vulnerabilities to external factors, but the principles of their failure are largely similar. Next, we will look at the technical aspects of the operation of the motor and typical scenarios for its destruction.
Critical influence of voltage drops in the electrical network
The most common cause of sudden death of a compressor is unstable power supply parameters. Voltage surges can occur in many ways reasons: from thunderstorms and accidents at the substation to the inclusion of powerful welding equipment by neighbors. The refrigerator electronics try to compensate for fluctuations, but sudden surges of current are often fatal to the motor windings.
Situations are especially dangerous when the voltage drops below the permissible minimum and then abruptly recovers. At such moments, the inrush current increases many times over, which leads to overheating and insulation breakdown. If the lights in your home frequently flicker or the plugs go out, the risk of expensive equipment failing increases exponentially.
⚠️ Attention: Installing a simple surge protector will not save you from power surges. For reliable protection, you need a full-fledged voltage stabilizer, selected according to the power of your refrigerator.
Modern models are equipped with protective electronics that turn off the power in the event of anomalies, but older units or budget lines often lack this option. As a result, the windings burn out instantly, or the contacts of the starting relay melt, which also blocks the operation of the system.
Faults in the start-up relay and thermostat
Often the compressor itself is working, but cannot start due to a breakdown of the auxiliary controls. Start relay responsible for providing an impulse to start the engine and its subsequent disconnection from the starting winding. If the relay contacts stick or burn, the motor hums but does not start, which quickly leads to its overheating and thermal shock.
A similar role is played by the thermostat (or temperature sensor), which gives the command to turn on the compressor. If the thermostat “sticks” in the closed state, the refrigerator operates without stopping, without going into rest mode. Constant operation at the limit of capabilities depletes the life of lubricants and mechanical components, leading to premature wear.
Diagnostics of these elements requires checking the resistance with a tester. In some cases, the relay can be replaced yourself if an exact copy is selected for your model, for example, for Indesit or Atlant. However, the incorrect selection of a component can finish off a compressor that is still working.
☑️ Diagnostics before calling a technician
It is important to note that frequent on and off cycles (short cycles) are also harmful to the system. This may be caused by incorrect thermostat settings or a freon leak, due to which the temperature does not have time to drop to the desired value, and the motor runs jerkily.
Mechanical wear and lubrication problems
Inside the sealed compressor casing there are rubbing parts: pistons, cylinders, shafts and bearings. For their normal operation, a special compressor oilis used. Over time, especially during long-term operation without maintenance or under high load conditions, the oil may lose its properties, thicken or decompose.
If the oil level drops or it stops flowing to the friction units, dry wear of the metal begins. This is accompanied by a characteristic metallic knocking, grinding and vibration. Ultimately, the piston may get stuck in the cylinder, and the engine, trying to turn the shaft, will burn out or blow out the automatic fuse.
| Type of malfunction | Symptoms | Probability of repair |
|---|---|---|
| Seizing shaft | Humming, no start, heating | Low (replacement required) |
| Bearing wear | Strong noise, vibration of the housing | Medium (pressing new ones) |
| Cylinder exhaustion | Reduced productivity, long-term cold | Low (not economically feasible) |
| Broken connecting rod | Rumbling, complete stop | Zero (replacement only) |
It is interesting that in inverter compressors mechanical wear occurs more slowly due to the absence of hard starting loads, but their complex electronic filling is more sensitive to the quality of lubrication and cleanliness of the system.
Why can’t you open the compressor yourself?
A vacuum is created inside the compressor and a special oil is located. When opened, the seal is broken, moisture and air enter, which makes further operation impossible without sophisticated industrial equipment for evacuation and charging.
Refrigerant leakage and dry operation
One of the insidious causes of breakdown is freon leakage from the cooling circuit. Many owners mistakenly believe that if the refrigerator has stopped freezing, then the problem is only in the gas. However, when the refrigerant level is low, the compressor continues to work, trying to reach the set temperature, but cannot do so.
In normal mode, freon not only transfers heat, but also participates in cooling the motor itself (in some designs) or provides normal pressure for oil return. When operating in “vacuum” or low pressure mode, the oil circulation is disrupted, it does not return to the compressor crankcase, and oil starvation occurs.
Long-term operation in this mode leads to overheating of the windings and mechanical destruction of the components. Thermal relay may be triggered, turning off the unit, but after cooling the cycle is repeated until irreversible breakdown.
⚠️ Attention: If you notice that the refrigerator is working almost non-stop, but there is no cold, immediately unplug it. Continuing operation in this mode is guaranteed to kill the compressor.
To eliminate this problem, it is not enough to simply replace the motor. A complete diagnosis of the circuit, search and elimination of leaks, replacement of the filter-drier, and only then - charging with new refrigerant and installation of a new compressor are required.
Improper operation and placement conditions
Often users themselves create conditions leading to breakdown, without even knowing it. Installing the refrigerator close to the wall or in a niche without gaps disrupts natural air circulation. The condenser (grid at the back) does not have time to give off heat, the temperature in the system rises, and the load on the compressor increases.
Another common mistake is loading hot products into the chamber. This causes a sharp jump in the temperature inside, the thermostat commands to work intensively, and the compressor is turned on for a long cycle, working at the limit of its capabilities. Frequent opening of doors in a hot room is also harmful.
Don't forget about transportation. Transporting the refrigerator lying down, especially on its side where the compressor is located, can lead to oil leakage into the refrigerant circuit. If you immediately turn on the device after such transportation, it may occur water hammerwhich can break the valves or piston group.
The rule says: after transportation in a lying position, the refrigerator must stand upright for at least 4-6 hours (or better yet a day) before turning it on so that the oil flows back into crankcase.
Natural wear and tear and manufacturing defects
Nothing lasts forever, and each technical device has its own resource. The average service life of a compressor ranges from 7 to 15 years, depending on the model and operating conditions. Over time, the metal gets tired, the wire insulation dries out, and the compression efficiency drops.
Sometimes the cause of the breakdown is a manufacturing defect. This may be poor quality assembly, the use of cheap materials for windings, or defects in the casting of the housing. Such problems often appear in the first year of operation. Such cases are covered by a warranty, and replacement under warranty is the only correct solution.
It is worth noting that some brands are known for more reliable compressors (for example, Secop, LG, Embraco), while others may use less resource-intensive components in budget rulers. However, even the most reliable unit will not survive constant power surges or operation with gas leaks.
What to do if the compressor breaks down: repair or replacement?
When diagnostics confirmed the death of the compressor, the owner is faced with the question: repair or replace? In 95% of cases, repairing the compressor itself (rewinding, replacing valves) is not economically feasible. The cost of work and spare parts often approaches the price of a new unit, and the tightness and service life of the restored unit are questionable.
The optimal solution is replacing the compressor to buy a new one. This procedure requires qualification: the master must desolder the old unit, weld in a new one, replace the filter drier, create a vacuum in the system and charge the exact amount of refrigerant. It is impossible to carry out this operation independently without a vacuum pump and a pressure gauge station.
When choosing a new compressor, it is important to consider not only the mounting dimensions, but also the power, type of refrigerant (R134a, R600a) and oil volume. An error in selection will lead to ineffective operation or rapid breakdown of the new unit.
⚠️ Attention: Technical characteristics of compressors and requirements for refrigerants may vary depending on the model and year of manufacture. Always check the markings on the nameplate of your refrigerator with the passport data of the new unit before purchasing.
If the refrigerator is more than 10-12 years old and its compressor has burned out, it is often more advisable to think about buying new equipment. Aging of other components (insulation, seals, electronics) can lead to new breakdowns soon after expensive engine repairs.
Is it possible to install a compressor of greater power?
Theoretically, it is possible if it matches the fastenings and type of freon. However, a more powerful motor will create excess pressure that the standard tubes and condenser cannot handle, which will lead to depressurization of the system.
Conclusion
A compressor is a complex mechanism that requires careful handling and stable operating conditions. Understanding why the compressor in a refrigerator breaks down allows you to eliminate many risk factors: install a stabilizer, correctly place the equipment and monitor the temperature in the chambers. Regular maintenance and careful attention to the first signs of malfunction can extend the life of your refrigerator for many years.
Why is the compressor hot, but does not start?
This is a classic sign of a stuck mechanical part or a faulty start relay. The motor tries to start, the current increases, the windings heat up, but it cannot move the shaft. Immediate disconnection from the network is required to avoid a fire.
You hear a clicking and buzzing sound, then silence - what is this?
Most likely, the thermal protection relay is triggered. The compressor tries to start, the current exceeds the norm, the relay heats up and opens the circuit. After cooling, the cycle repeats. The reason may be low voltage, a bad relay, or the beginning of a motor jam.
Is it possible to restore a burnt-out compressor?
At home, no. At specialized factories, it is theoretically possible to rewind the windings or replace the valve group, but the cost of such work and the risk of repeated breakdown make this idea pointless. It’s easier and more reliable to buy a new one.
How to extend the life of a compressor?
Do not place hot foods, provide ventilation at the back, do not touch the temperature regulator often and protect equipment from power surges with a high-quality stabilizer. Also, let the refrigerator “rest” when defrosting.
Why is the new compressor louder than the old one?
Modern models may have a different type of operation or simply be new, so vibration is transmitted differently. However, strong knocking or clanging is unacceptable - this is a sign of improper installation (the tubes are not welded, touching the body) or defective.