Sudden spoilage of food or the appearance of extraneous sounds in the kitchen are often the first signals that something is wrong with your refrigerator. Compressor, which is the heart of the entire cooling system, may stop functioning for various reasons, from a banal power surge to natural wear and tear of mechanical parts. You can understand that this particular unit has failed long before calling a technician if you know which symptoms to pay attention to first.
In this article we will analyze in detail all the stages of self-testing so that you can accurately determine the source of the problem. You will learn to distinguish a motor malfunction from problems with a thermostat or a freon leak, and will also understand when repairs still make sense, and when it is easier to purchase new equipment. Diagnostics doing it yourself will help you save time and avoid unnecessary expenses on specialist services if the breakdown turns out to be minor.
Basic signs of a compressor malfunction
The first and most obvious sign that motor-compressor is not working correctly is a change in the temperature conditions inside the chambers. If you notice that the food in the refrigerator compartment is starting to thaw, and the ice has disappeared from the freezer, this is an alarm bell. However, it is important not to panic ahead of time, as such symptoms may indicate other problems, for example, a loose door seal.
⚠️ Attention: If you smell a burning smell or see sparking in the rear wall area, immediately disconnect the device from the power supply. Operation of faulty electrical equipment can lead to a fire.
The second important marker is the nature of the engine itself. A working unit operates cyclically: it turns on, cools the chamber to the set temperature and turns off. If you observe that the refrigerator is humming continuously, without turning off for days, or, conversely, is silent, although it is warm inside, this indicates serious malfunctions in the operation of the motor windings. Loud knocking, clanging, metallic squeaking or intermittent buzzing with clicking sounds are not normal operating sounds. Often such noises indicate that the internal mechanical parts of the compressor have worn out or broken down. In some cases, the motor may try to start, emit a short beep and immediately go silent, after which the relay clicks. start relay or motor windings.
It is also worth listening to the sounds that the equipment makes. Loud knocking, clanging, metallic squeaking or intermittent buzzing with clicking sounds are not normal operating sounds. Often such noises indicate that the internal mechanical parts of the compressor have worn out or broken down. In some cases, the engine may try to start, emit a short beep and immediately go silent, after which the relay clicks.
Visual and tactile diagnostics of the motor
Before disassembling the back panel, conduct an initial inspection. Pay attention to the condition of the compressor housing. If, when you touch it with your hand (be sure to be dry!), you feel that the metal casing is hot to such an extent that it hurts to touch it, this is a sign of overheating. The normal temperature of a running engine is hot, but tolerable for the hand.
Inspect the area around the engine for traces of oil. The compressor is a sealed unit, and in normal condition no technical fluids should leak from it. The presence of oily stains on the floor under the refrigerator or on the part itself indicates depressurization, which is often accompanied by a refrigerant leak and failure of the piston group. Check the integrity of the wires going to the engine. Sometimes the problem lies not in the motor itself, but in melted insulation or oxidized contacts. Visually assess the condition of the start relay, which is usually mounted on the side of the compressor. If traces of soot or melting are visible on the plastic housing of the relay, this indicates a short circuit or overcurrent. piston group.
Check the integrity of the wires going to the engine. Sometimes the problem lies not in the motor itself, but in melted insulation or oxidized contacts. Visually assess the condition of the start relay, which is usually mounted on the side of the compressor. If the plastic housing of the relay shows signs of soot or melting, this indicates a short circuit or overcurrent.
Checking the start relay and electrical circuit
Often the reason that the refrigerator has stopped freezing is not the motor itself, but starting relay. This small block is responsible for starting the motor and protecting its windings from overloads. To check it, you need to carefully remove the relay from the compressor contacts. It is usually secured with latches or screws.
After removing the relay, you need to shake it next to your ear. If a ringing or knocking sound is heard inside, it means that the contact group is damaged and the part requires replacement. This is one of the most common and easily eliminated causes of equipment failure. You should also inspect the contacts for carbon deposits, which may interfere with the normal flow of electric current.
For a deeper check of the electrical circuit, you will need a multimeter. With its help, you can “ring” the motor windings for breaks or short circuits. Normal winding resistance varies depending on the model, but is typically between 10 and 30 ohms for the start and run windings, respectively. If the device shows infinity or zero, the engine is faulty.
☑️ Diagnostics of the starting relay
Table of symptoms and probable causes
For ease of systematization of the data obtained, use the following table. It will help to compare the observed symptoms with the most likely technical problems.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The engine hums, but does not start | Faulty start relay or jammed piston | Medium |
| The refrigerator runs non-stop | Freon leakage or compressor wear | High |
| Metallic noise is heard knock | Destruction of the engine mount or valves | High |
| Compressor is hot, no cold | Refrigerant leakage or winding breakdown | High |
It is important to understand that even if the symptoms indicate a compressor failure, a final diagnosis can only be made by a specialist with the appropriate equipment. For example, pressure measurement in the system can accurately indicate the presence of a leak that cannot be detected visually.
Mechanical damage and wear of parts
Inside the sealed compressor casing there is a complex mechanism consisting of pistons, cylinders and valves Over time, the metal gets tired, microcracks appear, and the lubricant loses its properties. Mechanical wear leads to the fact that the compressor ceases to create the necessary pressure for freon circulation.
One of the signs of mechanical failure is the so-called “soft running”. This is a situation when the motor is running, the shaft is spinning, but there is no pressure in the system. The food does not freeze, the condenser (grid at the back) remains cold or warm, and not hot, as it should be during normal operation. In this case, replacing the compressor is inevitable.
⚠️ Attention: Opening the sealed compressor casing at home is strictly prohibited. This requires special tools, evacuation of the system and charging with freon, which is only possible in service conditions.
Another cause of mechanical problems can be moisture getting into the system. Water that gets into the circuit along with oil or during poor-quality previous repairs causes corrosion of internal parts and the formation of ice plugs in the capillary tube. This leads to water hammer and rapid destruction valve group.
Why can’t you open the compressor yourself?
Inside the compressor there is a mixture of oil and refrigerant under pressure. When opened, harmful substances enter the atmosphere, and the entry of air and moisture into the system will lead to instant failure of the new compressor if you try to install it without evacuation.
The influence of external factors on engine operation
The cause of a breakdown does not always lie in the refrigerator itself. External factors often lead to compressor failure. For example, unstable voltage in the electrical network is the main enemy of electric motors. Voltage surges cause overheating of the windings and destruction of the insulation, which leads to an interturn short circuit.
The correct installation of equipment also plays an important role. If the refrigerator is too close to the wall or heat source (stove, radiator), heat exchange is disrupted. The compressor is forced to work with increased load to remove heat, which leads to overheating and accelerated wear. The gap between the back wall and the furniture should be at least 10 cm.
Frequently opening doors and placing hot foods inside also force the motor to work at its limit. Thermoregulator there is no time to turn off the engine, and it runs almost without interruption, which significantly reduces its resource.
Frequently asked questions (FAQ)
Is it possible to restore a burnt-out compressor?
It is impossible to restore a burnt-out compressor at home. A burnt-out winding inside a sealed housing cannot be replaced. A complete replacement of the unit with a new one or a contract one (used in good condition) is required.
How long does a compressor last in a refrigerator on average?
The average service life of a modern compressor is 10–15 years, provided proper operation and stable voltage in the network. Some models can work longer, but after 10 years the risk of breakdown increases significantly.
Why does the compressor turn on and off immediately?
This phenomenon is called “clocking”. Most often, the reason lies in a malfunction of the starting relay, which cannot keep the contacts closed to start, or in an interturn short circuit of the motor windings, which causes the thermal protection to trip.
Is it dangerous to leave a refrigerator running with a faulty compressor?
Leaving such a device connected to the network is dangerous. A faulty motor may draw more than its rated current, causing the wiring to overheat, melt the insulation, and potentially cause a fire. It is better to turn off the equipment before the technician arrives.