Sudden defrosting of food or the appearance of puddles under the refrigerator often becomes an unpleasant surprise, signaling serious problems with cooling system. The heart of any household refrigerator is the compressor, and it is its failure that most often leads to a complete stop in the operation of the unit. Understanding how to determine a compressor malfunctionallows you to react in time and minimize food losses, as well as avoid more expensive repairs in the future.
Diagnostics of this unit does not always require complex equipment; Often, careful observation of the behavior of the equipment and analysis of sound signals is sufficient. In this article we will analyze in detail the main symptoms, testing methods and nuances that will help you understand whether your compressor needs replacement or repair. Do not ignore the first signs, as the operation of a faulty motor can lead to an overload of the electrical network.
Analysis of sound signals of a working unit
The first and most accessible indicator of the condition of the equipment is sound. A working refrigerator operates relatively quietly, emitting only a uniform hum when the motor is running. If you begin to notice extraneous noisesuch as metallic clanging, knocking or intermittent humming sounds, this is a direct signal of mechanical problems within the sealed enclosure. It is especially alarming if these sounds appear when starting or stopping the engine.
Often a faulty compressor makes a characteristic click when trying to start, followed by silence or a short hum. This may indicate that the starter relay is unable to start the rotor, or that the motor itself is seized. In some cases, the motor begins to work without stopping, emitting a continuous, intense hum, which indicates a loss of performance and an inability to gain the required pressure in the system.
- 🔊 A loud metallic knock or clanging inside the motor housing indicates destruction of the piston group or valves.
- ⚡ A characteristic click of the relay followed by silence indicates the destruction of the piston group or valves. impossibility of starting the motor rotor.
- 🔄 Intermittent humming with pauses may indicate problems with the windings or overheating.
- 🤫 Complete absence of sound when the refrigerator is plugged in often means an open circuit or motor burnout.
⚠️ Attention: If If you hear a loud cracking sound or a burning smell, immediately unplug the refrigerator from the power supply. Continued operation may lead to a fire in the wiring or a complete replacement of the refrigeration unit.
It is important to distinguish between the sounds made by the compressor itself and noise from vibration of the tubes or housing. Sometimes it is enough to simply fix the refrigerator to eliminate rattling, but if the source of the sound is localized precisely in the area of the motor, the situation is more serious. Diagnostics by sound This is the primary stage, which helps to narrow down the range of possible causes of failure.
Temperature anomalies and system operation cooling
The main function of the compressor is to circulate refrigerant through a system of tubes. If this process is disrupted, you will immediately notice changes in the temperature inside the chambers. Food begins to deteriorate, ice melts in the freezer, and condensation disappears on the walls of the refrigerator compartment or, conversely, excessive moisture appears. These are classic signs that freon circulation is missing or insufficient. At the same time, the compressor itself may behave differently. In one case, it will work continuously, trying to achieve the specified parameters, but unable to cope with the load. In another, the motor may not turn on at all, although the indicators on the control panel will light up, signaling the need for cooling. This situation often occurs when freon circulation missing or insufficient.
In this case, the compressor itself may behave differently. In one case, it will work continuously, trying to achieve the specified parameters, but unable to cope with the load. In another, the motor may not turn on at all, although the indicators on the control panel will light up, signaling the need for cooling. This situation often occurs when interturn short circuit windings.
Touching the condenser (the grille at the back of the refrigerator) also provides important information. When working properly, it should be warm or hot evenly over the entire area. If you notice that only part of the grille is heating up, or it remains cold while the engine is running, this indicates that the refrigerant is not circulating. The cause could be a compressor breakdown, a freon leak, or a clogged system.
It is worth paying attention to the temperature of the motor housing itself. If the compressor is working, but its housing is heated to temperatures at which it is impossible to hold your hand for more than 2-3 seconds, this is a sign of overheating. Thermal relay in such a situation the engine should be turned off, but if it is faulty, the motor will continue to wear out, which will inevitably lead to its final failure.
Visual inspection and check of the electrical part
Before making final conclusions, it is necessary to conduct a visual inspection. Unplug the refrigerator, move it away from the wall and reach the compressor located at the bottom rear. Carefully inspect the motor housing for swelling, oil stains or traces of soot. The presence of oil around the tubes may indicate depressurization, which often accompanies mechanical failures.
Next is a check of the electrical contacts. Remove the protective casing from the compressor where the start and thermal relays are located. Inspect the wires for melted insulation, oxidation of contacts, or burnt terminals. If you see traces of burning or smell burnt plastic, the problem may lie not only in the motor, but also in the launch control system.
- 👁️ Visually assess the condition of the wires: they should be intact, without cracks or blackening.
- 🔌 Check the tightness of the terminals on the contacts of the compressor and relay.
- 💧 Look for oily spots on the floor under the refrigerator or on the unit itself.
- 🌡️ Feel the motor housing (carefully if it has just been running) for uneven heating.
⚠️ Attention: All work on removing casings and Carry out inspection of electrical parts ONLY when the refrigerator is completely disconnected from the network. Residual voltage or accidental switching on can lead to electric shock.
Often the cause of the “death” of the compressor is a malfunction of the starting relay. This is an inexpensive part that protects the motor. If the relay is stuck or burnt out, it may not provide the necessary impulse to start, creating the illusion of a breakdown of the engine itself. Therefore, relay diagnostics is a mandatory step before deciding to replace an expensive compressor.
How to check the starting relay?
To check the relay, you need to remove it and shake it. If a clear knocking sound of a ball or tongue is heard inside, this does not always mean a breakdown, but it is better to check it with a multimeter. The resistance must be within the normal range, and the contacts must not be oxidized. Often, replacing the relay solves the starting problem, even if the motor itself is working.
Instrumental diagnostics: checking with a multimeter
To more accurately determine the condition of the engine, you will need a multimeter. This device will allow you to check the integrity of the windings and the absence of breakdown on the housing. First you need to remove the terminals from the compressor contacts and set the multimeter to measure resistance (Ohmmeter mode). There are usually three contacts on the motor body: common, starting and working.
Checking is done by measuring the resistance between different pairs of contacts. Normal resistance values depend on the power of the motor, but usually range from 10 to 30 ohms between the working and starting windings. If the device shows infinity (break) or zero (short circuit), this is a sure sign of a malfunction of the windings.
It is also critically important to check that there is no breakdown on the housing. To do this, one multimeter probe is applied to any contact (preliminarily cleaned), and the second is applied to a copper tube or metal housing of the compressor. The device should show infinity. If there is at least some resistance value, it means that the insulation is broken, and operating such a refrigerator is strictly prohibited due to the risk of electric shock.
☑️ Diagnostics with a multimeter
It is best to check the measurement results with the technical data of a specific model, since different manufacturers (for example Atlant, Indesit, LG) may have different standards. However, the general principles remain the same: the windings should ring, but the body should not. If the data deviates greatly from the norm, the compressor requires replacement.
Comparative table of symptoms and causes
To systematize the knowledge gained and facilitate the diagnostic process, we have prepared a summary table. It will help you correlate observed symptoms with the most likely technical causes. Remember that the same symptom can indicate different problems, so an integrated approach is important.
| Observed symptom | Probable cause | Necessary actions | Difficulty of repair |
|---|---|---|---|
| Click when starting, then silence | Faulty start relay or jammed piston | Replace the relay, check the compressor | Low / High |
| The engine is humming, but does not start | Low voltage in the network or interturn short circuit | Voltage measurement, checking the windings | Average |
| The refrigerator does not freeze, the motor is cold | Open circuit, burned out winding or thermostat | Checking the circuit with a multimeter | Average |
| Continuous operation without shutting down | Freon leakage, compressor wear, loose closure doors | Search for leaks, replace the motor | High |
| Strong vibration and noise | Destruction of internal elements, loosening of fastenings | Replacement of shock absorbers or compressor | Medium / High |
Analyzing the table data, you can see that some problems can be solved relatively simply, for example, by replacing a relay or eliminating current leakage. However mechanical destruction the internals of the compressor require a complete replacement of the unit, which is a complex procedure that requires special equipment for working with refrigerant.
Making a decision: repair or replacement
When the diagnosis is made and it is confirmed that the compressor is faulty, the question arises about the feasibility of repair. Unlike some other components, the compressors of modern refrigerators are practically impossible to repair at home. Opening the sealed casing and rewinding the motor requires factory conditions and special equipment.
Therefore, in the vast majority of cases, replacing the compressor is the only viable solution. This process includes not only dismantling the old motor and installing a new one, but also evacuation of the system, refilling with freon and replacing the filter drier. It is extremely difficult and risky to carry out these operations on your own without hiring a refrigeration technician.
It is also worth considering the age of the refrigerator. If the equipment is more than 10-12 years old, replacing the compressor may not be economically feasible, since the cost of work and new spare parts can be a significant part of the price of a new refrigerator. In such cases, it is sometimes more profitable to purchase a new unit than to reanimate the old one.
⚠️ Attention: Prices for expert services and spare parts may vary depending on the region and model of the refrigerator. Before starting work, check the current cost with service centers, as conditions may change.
If you decide to replace, make sure that the new compressor fully matches the characteristics of the old one. The use of analogues with other parameters can lead to incorrect operation of the cooling system and rapid wear of new parts. Professional installation guarantees the tightness of the system and the correct dosage of refrigerant.
Is it possible to start a refrigerator with a faulty compressor?
You cannot start a refrigerator with a obviously faulty compressor. This may result in a short circuit, electrical fire, or electric shock. In addition, the operation of a faulty motor will not bring cold, but will only aggravate the situation.
How long does a refrigerator compressor last on average?
The average service life of a modern compressor is 10-15 years, provided proper operation and stable voltage in the network. However, some models can work longer, up to 20 years, if they are properly cared for.
Why can a new compressor burn out quickly?
A new compressor often burns out due to installation errors: insufficient evacuation of the system, the presence of moisture, incorrect refilling with freon or the use of the wrong oil. Also, the cause may be power surges in the network.
How to extend the life of a compressor?
To extend the service life, you should regularly defrost the refrigerator (if it is not No Frost), do not place it close to the wall for good ventilation, keep the condenser at the back clean, and use a voltage stabilizer when the power supply is unstable.