The situation when you open the refrigerator, and it’s warm inside, and the food begins to spoil, causes panic in any home cook. If you notice that The refrigerator motor does not workthis indicates a serious problem with the cooling system that requires immediate attention. The compressor is the heart of the unit, and stopping it leads to defrosting of the chamber and loss of reserves.
In most cases, the reason lies not in the breakdown of the engine itself, but in auxiliary elements or a banal power surge. Before calling a technician or buying a new unit, it is worth conducting a thorough initial diagnosis. Often you can solve the problem yourself if you know where to look for a fault.
In this article we will analyze in detail the algorithm of actions in case of compressor failure, consider typical symptoms of a breakdown and explain how to check the main components. Timely detection malfunction can save your refrigerator from an expensive overhaul or complete replacement.
Primary diagnosis: why the compressor is silent
The first thing to do if the refrigerator motor does not start is to listen to the operation of the unit. Normally, the compressor should hum intermittently. If there is absolute silence or, conversely, a humming sound is heard, but startup does not occur, you need to look for the reason. No startup can be caused by both external factors and internal defects.
⚠️ Attention: Before starting any diagnostic work, be sure to disconnect the refrigerator from the power supply. Working with live electrical appliances is life-threatening!
Start by checking the power supply. Make sure that the plug is firmly inserted into the outlet and that the cord itself is not damaged. Try plugging another device into the same outlet, such as a lamp or hair dryer, to rule out problems with the wiring in your home. If the socket is working, but the refrigerator is silent, the problem is inside.
Pay attention to the nature of the sound that the motor makes when you try to turn it on. A short click followed by silence often indicates a protection has tripped or a faulty trigger mechanism. If you hear a hum that lasts a few seconds, and then a click and stop, this is a sure sign that motor rotor the starting winding is jammed or is not working.
It is also important to check the temperature conditions in the chamber. If it is warm inside, but the motor does not work, the overheating protection may have tripped and the unit needs time to cool down. Leave the refrigerator turned off for 2-3 hours and then try to start it again. If the situation repeats, you will have to disassemble the back wall for a detailed inspection.
Checking the start relay and thermostat
One of the most common reasons why the refrigerator motor does not workis the failure of the start relay. This small element is responsible for starting the engine by sending an impulse to the starting winding. If the relay burns out or the contacts are stuck, the motor will not receive a signal to start. Usually the relay is located in a box on the side or back of the compressor.
To check the relay, it must be carefully removed. Visually inspect the contacts: if they are blackened or melted, the part requires replacement. You can also shake the relay near your ear: if you hear a knock, it means the internal mechanical part is damaged. Replacing a relay is an inexpensive procedure and can often be done with your own hands.
How to check a relay with a multimeter?
For accurate diagnostics, take a multimeter in dial mode. Ring the relay contacts. If the device shows infinite resistance or, conversely, a short circuit where it should not be, the relay is faulty. The normal coil resistance is usually several tens of ohms.
The second important element is the thermostat (thermostat). It is he who gives the command to the compressor to turn on when the temperature in the chamber rises above the set one. If the thermostat is broken and does not “see” heat, it simply will not close the circuit and the engine will not start. You can check it by connecting the contacts with wires directly (temporarily!). If after this the refrigerator starts working, the thermostat is to blame.
It is worth noting that in modern models with electronic control, instead of a thermostat, there may be a temperature sensor connected to the control module. In this case, diagnosis is more difficult and requires special equipment. However, in classic models mechanical thermostat remains a frequent culprit of problems.
Diagnostics of the compressor and starting capacitor
If everything is in order with the relay and thermostat, attention turns to the engine itself. Refrigerator compressor - this is a sealed unit, and you can’t just look inside. However, you can check its electrical parameters. For this you will need a multimeter. It is necessary to measure the resistance between the contacts of the motor windings.
Normal resistance values depend on the motor model, but usually they are in a certain range. If the device shows an open circuit (infinity) or a short circuit (zero or very small value), then the winding has burned out. In this case, repair of the compressor is impossible - a complete replacement of the unit is required.
☑️ Checking the electrical part
The starting capacitor may also be the cause of the failure. It helps the engine gain momentum. If the capacitor is swollen or has lost capacity, the motor will hum but will not start. You can check the capacitor visually (blowing of the housing, drips) or with a capacitance measuring device. Replacing a capacitor is a simple procedure that requires a minimum of tools.
It is important to remember safety when working with capacitors. Even after unplugging, they may still have a charge. Before checking, it is recommended to discharge the capacitor by closing its contacts with a screwdriver with an insulated handle (being careful!).
Symptoms of interturn short circuit and breakdown to the housing
One of the most serious problems is interturn short circuit in the motor windings. This occurs when the insulation of the wire inside the winding is broken and the turns become shorted together. As a result, current strength increases sharply, thermal protection is triggered, and the motor stalls. After some time, it cools down and tries to start again, but the cycle repeats.
It is difficult to diagnose an interturn short circuit, since the multimeter may show normal resistance. An indirect sign is the strong heating of the compressor housing and the knocking out of plugs (automatic devices) in the shield when turned on. If the machine knocks out instantly when the refrigerator starts, this is almost guaranteed to be a winding breakdown.
A breakdown to the housing is another dangerous malfunction. In this case, one of the winding wires is in contact with the metal body of the motor. You can check this by measuring the resistance between any contact and the copper tube or compressor housing. The device should show infinity. If there is at least some value, the engine is faulty and requires replacement.
⚠️ Attention: Operating a refrigerator with a breakdown in the body is deadly! Touching metal parts of the unit may result in electric shock. Turn off the device immediately.
Often, an interturn short circuit is a consequence of prolonged operation in abnormal mode, for example, with a faulty thermostat, when the motor runs non-stop. Overheating destroys the insulation, which ultimately leads to a short circuit.
The influence of the No Frost system and sensors
Owners of modern refrigerators with the system No Frost may encounter a situation where the motor does not start due to a failure in the defrost system. If the defrost sensor or evaporator heating element is faulty, ice can block the fan or create excess pressure, which indirectly affects the operation of the compressor through the protection system.
In addition, in such models, the electronic control module is often responsible for starting the motor. If it is “buggy” or receives incorrect data from sensors, the launch command may not be received. In this case, professional diagnostics using a tester are required.
A comparison of the main causes of motor failure is presented in the table below:
| Cause | Symptom | Difficulty of repair | Required tools |
|---|---|---|---|
| Thermostat malfunction | Silence, no buzzing | Low | Screwdriver, multimeter |
| Burnt start relay | Click, no start | Low | Screwdriver, pliers |
| Compressor jammed | Humming 5-10 sec, click | High (replacement) | Soldering kit, freon |
| Interturn short circuit | Knocks out machines, heating | High (replacement) | Multimeter, new compressor |
As can be seen from the table, many problems can be solved, but some require specialist intervention. Replacing a compressor yourself requires skills in soldering copper tubes, evacuating the system and charging refrigerant.
When a call to the master is necessary
Despite the desire to save money, there are situations when do-it-yourself repair is not only impractical, but also dangerous. If you determine that the problem is in the compressor itself (burnt out, jammed), the best solution is to contact a service center. Replacing a motor is a labor-intensive process.
A master is needed if required:
- 🛠️ Replacement compressor: requires bleeding out old freon, soldering tubes, evacuating the system and accurately charging the refrigerant.
- 🔌 Repair of electronic board: control modules are complex and require circuitry knowledge to restore.
- ❄️ Elimination of capillary blockage systems: often accompanied by replacement of the filter-drier and complete refilling of the circuit.
An attempt to replace the motor yourself can lead to a violation of the tightness of the circuit, moisture entering the system and the final failure of the refrigerator. In addition, working with refrigerants requires a license and special equipment.
⚠️ Attention: Never cut or solder the copper tubes of the refrigerator while it is plugged in or there is pressure in the system. The refrigerant may be flammable or toxic.
Prevention and extension of service life
To prevent the question “why the motor does not work” from arising too often, it is important to follow the operating rules. Defrost the refrigerator regularly (if it is not No Frost), wash the condenser (grid at the back) from dust and ensure that the door is tightly sealed. Overheating is the main enemy of the compressor.
Install the refrigerator away from heat sources (batteries, stove) and provide clearance for rear ventilation. Do not place hot food in the chamber - this will put extra stress on the motor. Following these simple rules will significantly extend the life of your unit.
How often should you wash the condenser?
It is recommended to clean the radiator grille at the back of the refrigerator from dust and animal hair at least once a year. A condenser clogged with dust does not give off heat well, the motor overheats and operates under increased load.
Frequently asked questions (FAQ)
Is it possible to restore a jammed compressor?
There is a method of “wedging” by applying increased voltage (380V) for a short time, but doing this at home is extremely dangerous and ineffective. In 95% of cases, a jammed motor must only be replaced.
Why does the refrigerator hum but not cool?
If the motor hums, it means it is working, but there is no cold. This may indicate a freon leak, a clogged capillary tube, or a fan malfunction (in No Frost models). The compressor itself may be in good order.
How much does it cost to replace a compressor?
The cost consists of the price of a new motor and the work of a technician. On average, replacement costs 40-60% of the cost of a new refrigerator. If the unit is old, it is often more profitable to buy a new one.
Can a voltage surge kill the motor?
Yes, a sharp voltage surge can break through the insulation of the windings or damage the starting relay. For protection, it is recommended to use a voltage stabilizer or a voltage control relay.
How to understand that the thermostat has burned out?
If you close the wires coming from the thermostat and the refrigerator starts working, it means the thermostat is faulty. Another sign may be the absence of a characteristic click when turning the temperature control knob.