The situation when the inside of the refrigeration chamber suddenly becomes warm and the products begin to deteriorate always takes you by surprise. You open the door, expecting the usual cold, but instead you feel room temperature. The first thing any owner does at this moment is listen to the operation of the unit. There may be no engine hum at all, or you may only hear quiet clicks, followed by silence again. This is a sure sign that refrigerator compressor has stopped performing its function.
Failure of the main unit of the cooling system is a serious problem that requires immediate attention. Without refrigerant circulation through the circuit, heat is not removed from the chambers, and the temperature rises steadily. Refrigeration unit can remain silent for various reasons: from a banal power surge in the network to complex mechanical damage to internal parts. Understanding the nature of the malfunction will help you decide whether you should try to fix the problem yourself or whether you need to call a technician.
In this article we will analyze in detail all possible breakdown scenarios. You will learn how to carry out initial diagnostics yourself, what sounds and indicators you need to pay attention to. We will look at the device motor-compressor and auxiliary elements so that you can clearly imagine what is happening inside the technical compartment of your household appliance.
⚠️ Attention: Before starting any diagnostic work, be sure to disconnect the refrigerator from the electrical network. Working with electrical appliances under voltage is deadly, even if external signs indicate a lack of current.
Main signs of a compressor malfunction
Before disassembling the back panel and getting to the insides, it is necessary to clearly identify the symptoms. Owners often confuse a compressor failure with other faults, such as a freon leak or a broken thermostat. A characteristic sign of a mechanical or electrical problem with the motor is the complete absence of the characteristic hum and vibration, which are usually transmitted to the housing.
In normal operation refrigeration compressor it produces a monotonous low-frequency sound. If you don't hear it at all, or if the unit only makes a short series of clicks followed by silence, this indicates that the engine is not starting. It is also worth paying attention to the temperature of the rear grille (condenser). If it is cold, although the refrigerator has been plugged in for several hours, it means there is no gas circulation.
Sometimes you can observe strange behavior: the motor tries to start, hums strainedly for a few seconds, and then there is a loud click and it goes silent again. This is the work of a thermal protection relay that cuts off the power to prevent the windings from overheating or catching fire. This situation often indicates interturn short circuit or jamming of the piston group.
- 🔇 Complete absence of sound from the engine when the power is on.
- 🔊 Loud clicks of the relay followed by a stop motor.
- 🌡️ Warm or room temperature of the condenser grille at the rear.
- 💡 Burning emergency indicator (if provided by the model).
Problems with the power supply and the starting relay
One of the most A common reason why the compressor does not start is a malfunction in the current supply circuit to the motor windings. Unlike simple electrical appliances, the refrigerator has a complex starting system. The key element here is starting relay. It is this small block that is responsible for sending an impulse to the starting winding in order to spin the motor shaft.
If the relay fails, the engine receives power only to the working winding, but it does not have enough torque to start. As a result, the shaft stands still, the current increases, and the protection is triggered. You can check the relay visually (for melting) or by replacing it with a known good one. It is also worth checking the integrity of the wires going to the terminal box, since vibration during operation could cause them to break.
The condition of the electrical network cannot be discounted. Voltage surges could damage not only the relay, but also the motor winding itself. In modern models, an electronic control module is responsible for this, which could also fail. If you have a multimeter, you can check the presence of voltage at the compressor inlet, but this must be done extremely carefully.
Often owners forget about the simplest element - the thermostat. If it is faulty and does not close the circuit, the signal to start the engine simply will not be received. In some models with electronic control (No Frost), this is responsible for the temperature sensor, which could oxidize or lose contact.
How to check the starting relay without instruments?
Take the relay in your hand and shake it. If a rattling sound is heard inside, as if a part has fallen off, then the coil or core is damaged and the relay must be replaced. If there is no sound, this does not guarantee serviceability, but indicates the integrity of the structure.
Mechanical wear and jamming of the compressor
The most unpleasant scenario is the physical destruction of the internal mechanisms. Piston group inside the sealed casing is subjected to colossal loads. Over time, the metal gets tired, scuffs appear on the cylinders, and eventually the piston can become tightly jammed. In this state, the motor shaft cannot rotate even when full voltage is applied.
Seizing often occurs after long periods of inactivity. If the refrigerator was turned off for a long time, oil could drain into the lower part of the crankcase, and corrosive deposits could form on the rubbing surfaces. When trying to start, the engine hums, trying to move the piston, but to no avail. Sometimes the method of “warming up” the windings by briefly applying increased voltage helps, but this is a risky procedure that requires experience.
Another mechanical problem is a break in the piston rod or connecting rod. In this case, the engine runs, the shaft rotates, but the piston does not move and gas compression does not occur. A characteristic sign of such a breakdown is that the motor runs continuously without turning off, but the refrigerator does not freeze, and the compressor itself may be hot.
| Type of malfunction | Sound sign | Case temperature | Probability repair |
|---|---|---|---|
| Piston jamming | Humming, then clicking | Getting very hot | Low (replacement) |
| Rod breakage | Uniform hum | Warm | Low (replacement) |
| Valve wear | Hissing, whistling | Normal | Medium (replacement) |
| Burnt winding | Silence or crackling | Cold | Low (replacement) |
Standing It should be noted that opening a sealed compressor casing at home is impossible without special equipment and skills. If the diagnosis has confirmed mechanical failure of the internals, unit usually the entire unit is replaced with a new or restored one.
Electrical breakdowns and combustion of windings
Inside each compressor there are two or three windings: working, starting and sometimes additional. They are wound with thin copper wire coated with varnish. Overheating or voltage surges may cause the insulation to deteriorate, (causing) a short circuit. This phenomenon is called an interturn short circuit.
If the winding breaks down on the housing (short to ground), the circuit breaker in the apartment or the RCD is triggered when the refrigerator is turned on. This is a protective reaction that prevents fire. You can check for breakdown using a multimeter in resistance measurement mode. One probe is placed on the contact of the terminal block, the other - on a copper tube or an unpainted part of the case.
If the device shows a resistance close to zero or, conversely, infinity where the circuit should be, then the winding is burned out. It is possible to restore a burnt winding in a service center, but most often it is more economically feasible to buy a new compressor. Old models, for example Atlant or Don, often have standardized fasteners, which simplifies replacement.
☑️ Electrical diagnostics
⚠️ Attention: If a breakdown is detected during testing, further operation of the refrigerator is prohibited. This creates a direct threat of electric shock when touching metal parts of the housing or products.
The influence of external factors and improper operation
The reason does not always lie inside the motor itself. Often the compressor does not work due to external conditions that disrupt its normal cycle. For example, if the refrigerator is too close to the wall or radiators, heat exchange is disrupted. The motor overheats, and the thermal relay constantly turns it off, preventing it from reaching the desired temperature.
Frequent and sudden voltage drops in the electrical network are the scourge of modern technology. Even if the surge did not result in immediate combustion, it could damage the starting electronics or the capacitor (if there is one in the circuit). The use of voltage stabilizers can extend the life of the compressor, but does not guarantee protection against all problems.
It is also worth mentioning transportation. If the refrigerator was transported lying down and immediately turned on, oil could get into the refrigerant circuit. The compressor, trying to compress the liquid (oil), receives a hydraulic shock, which leads to valve failure or jamming. It is necessary to allow the equipment to stand upright for at least 4-8 hours after transportation.
Diagnostics and troubleshooting methods
If you determine that the compressor is not working, the action algorithm should be consistent. First, simple reasons are excluded: check if there is light in the chamber, if the door is tightly closed, if the temperature is set correctly. Then proceed to listening and visual inspection.
For a deeper diagnosis, you will need a tool. A multimeter will allow you to check the integrity of the windings and the presence of a breakdown. A pressure gauge station is needed to check the pressure in the system, which will indicate the performance of the compressor. If you do not have the skills to work with these devices, it is better to stop at the stage of visual inspection and call a specialist.
Replacing a compressor is a complex technological process. It requires:
- 🛠️ Pumping out the old refrigerant into a special receiver.
- 🔥 Soldering copper tubes with a torch using solder.
- 💨 Evacuating the system to remove moisture and air.
- ❄️ Refilling the exact amount of freon according to the model passport.
It is impossible to perform these operations independently without equipment. However, anyone with basic skills can replace the start relay or check the integrity of the wires to the compressor. The main thing is to follow safety precautions and not damage the copper tubes during dismantling.
Is it possible to restore a jammed compressor?
There is the "wedging" method by applying increased voltage to the starting winding for a split second. This allows the piston to be pulled out of place. However, this method is dangerous, requires a special transformer and gives only a temporary effect. Most often, such a compressor will soon jam again or burn out completely.
Why does the compressor hum but does not start?
This is a classic sign of a jammed piston group or a faulty start relay. The motor is trying to turn the shaft, but the mechanical resistance is too great. The current in the windings increases, and the thermal protection opens the circuit, making a click. After some time, the cycle repeats.
How much does it cost to replace a compressor?
The cost consists of the price of the unit itself (which can vary from 3 to 10 thousand rubles depending on the model) and the cost of the work of the technician. As a result, repairs can cost 50-70% of the price of a new refrigerator, so it is often more advisable to consider purchasing new equipment.
Is it dangerous to touch a hot compressor?
Yes, during operation the temperature of the compressor housing can reach 80-90 degrees Celsius and higher. Touching may cause burns. In addition, hot parts may contain technical oil, which causes irritation upon contact with skin.