Sudden, frighteningly loud click in a quiet apartment, it often becomes an alarm for the owner of household appliances. When the refrigerator turns off loudly, this not only disturbs the peace of the household, but can also indicate serious malfunctions in the operation of the electromechanical system. The sound can vary from a dull thud to a loud crack, and it is extremely undesirable to ignore such manifestations.
In most cases, such acoustic effects are associated with a sharp blurring of electrical contacts or mechanical locking of the moving parts of the motor. Understanding the nature of this sound is the first step to preventing costly repairs. Compressor It is the heart of the system, and any anomalies in its operation require immediate attention.
Often users confuse normal operating noise with signs of a breakdown, but the characteristic “thump” when turned off is rarely a normal occurrence for a working unit. In this article we will analyze in detail why such situations arise, how to carry out an initial diagnosis and in which cases professional intervention is necessary.
The nature of loud sounds when stopping
To understand why a loud shutdown occurs, it is necessary to consider the physics of the stopping process electric motor. At the moment when the thermostat gives the command to stop working, the current in the circuit is abruptly interrupted. If there is a malfunction in the system, this process is accompanied by arcing or mechanical shock.
One of the main reasons is the inertia of the rotating parts. Rotor a compressor, which has a large mass, during a sudden loss of power can create vibration, which is transmitted to the housing and amplified by metal walls cameras. If the fastenings are loosened, the sound becomes metallic and ringing.
It is also worth considering the operation of the solenoid valve in modern models with the system No Frost. When switching to rest mode, the valve may emit a characteristic click, which is quiet when in good condition, but when malfunctioning becomes frighteningly loud.
⚠️ Attention: If a loud click is accompanied by a burning smell or sparking in the area of the back wall, immediately unplug the device. Operation in this mode may lead to a fire in the wiring.
It is important to distinguish between the sounds produced by the compressor itself and the sounds that come from other components. For example, a cracking sound can come from plastic elements of the housing that expand or contract due to temperature changes, but this occurs cyclically and is not always tied strictly to the moment the motor is turned off.
Malfunctions of the starting and protective relay
The most likely culprit for loud clicks when turning off (and trying to turn on) is starting relay. This small element is responsible for supplying a starting pulse to the motor winding and its subsequent shutdown. Inside the relay there is a coil and a movable core, which produce sounds during operation.
If the relay contacts are oxidized or burnt, the process of opening the circuit becomes unstable. Instead of a clean break, a microscopic electrical arc occurs, creating a cracking sound. Over time, this leads to sticking of the contacts, and the relay ceases to perform its function, making loud clicks.
How does a relay work?
Inside the start relay there is a coil that, when current is applied, creates a magnetic field. It retracts the core, closing the contacts to start the engine. When the engine picks up speed, the current drops and the core, under the influence of gravity or a spring, returns to its original position, opening the circuit. This mechanical return causes the click.
The protective relay, often combined with the starting relay in one housing, can also be a source of noise. It reacts to overheating or overcurrent. If thermal protection trips frequently due to problems with the compressor, the bimetallic plate inside the relay will constantly click, trying to break the circuit.
- 🔊 Loud single click: most often indicates a mechanical opening of the relay contacts.
- 🔊 A series of quick clicks: indicates an attempt to start and an instant stop due to protection.
- 🔊 Crackling or buzzing: a sign of burning contacts or unstable current flow.
Replacing a relay is one of the most common repair procedures. For models Indesit, Atlant or Bosch these parts are often unified, but require selection according to power and type of compressor. An incorrectly selected relay will not work correctly and make noise.
Problems with the compressor and water hammer
The most serious and expensive cause of loud sounds is a malfunction of the compressoritself. If the piston group is worn out or there is a disruption in the circulation of the refrigerant in the cooling system, a so-called water hammer may occur when the engine stops.
Liquid freon, which has not had time to evaporate in the evaporator, may enter the suction pipe of the compressor. When the piston suddenly stops, the incompressible liquid creates a powerful shock wave. It is this that causes a dull, but very strong blow inside the unit body.
Another option is mechanical jamming. If the crankshaft bearings are worn out or the connecting rod bearings have rotated, the rotor may jerk sharply when stopping, hitting the housing walls or other internal elements. This is often accompanied by a metallic clang.
| Sound type | Probable cause | Urgency of repair |
|---|---|---|
| Thud blow | Hydraulic shock with freon | High |
| Metal clanging | Destruction of the motor mount | Medium |
| A loud click | Relay or valve | Low/Medium |
| Crackling | Electric arc in contacts | High |
Diagnostics of the compressor requires special tools, such as a pressure gauge station and a tester. At home, you can only assess the nature of the sound and the temperature of the motor housing. If, after a loud click, the compressor gets very hot and does not start again, it is likely to fail.
The influence of the No Frost system and defrosting
In refrigerators equipped with the system No Frost, loud sounds when turned off may be associated with the operation of the defrost system. Although the main noise usually occurs when fans or heating elements are turned on, the completion of the cycle can also be accompanied by acoustic effects.
Deformation of plastic elements of air ducts due to a sudden change in temperature (thermal expansion) is often perceived as a loud crack or click. This occurs at the moment when the compressor turns off and the temperature in the chamber begins to rise, starting the defrost cycle.
It is also worth mentioning the operation of the air flow regulator damper. If the damper mechanism is jammed or its drive is faulty, the damper motor may make loud clicks, trying to overcome resistance or locking in the extreme position when the power is turned off.
Sometimes the ice accumulated on the evaporator, when melting, falls onto the heating element or the bottom of the chamber with a characteristic knock. This sound may coincide in time with the compressor stopping, creating the false impression that it is the motor that is making noise.
Diagnostics: step-by-step instructions
Before calling a technician, you can conduct independent diagnostics, which will help narrow down the troubleshooting. This will allow you to more accurately describe the problem to a specialist or, perhaps, fix it yourself.
First of all, listen to the nature of the sound. Is it one-time or recurring? Does it come from the bottom (where the compressor is) or from the top (where the evaporator and ducts are)? A visual inspection can also provide important clues.
☑️ Primary diagnosis
Check the voltage in the network. Low or unstable voltage often causes start relay to work in emergency mode, constantly clicking and trying to start the motor. Using a voltage stabilizer can solve the problem if it is caused by external factors.
If possible, carefully remove the back cover of the refrigerator (with the power off!) and inspect the wires. Look for signs of melting, soot, or loose connections. Any sparking wiring must be replaced immediately.
When you need to call a technician
There are a number of symptoms in which self-repair is not only ineffective, but also dangerous. If, after a loud click, the refrigerator stops freezing, and the compressor either does not start or runs constantly without stopping, this is a sign of a serious breakdown.
Intervention in the refrigerant circulation system requires a license and special equipment. Trying to replace the compressor yourself or digest the tubes can lead to complete failure of the equipment and violation of environmental standards.
⚠️ Attention: Never try to repair the electrical part of the refrigerator if you do not have the appropriate knowledge and have not disconnected the device from the power supply. The risk of electric shock is extremely high.
A master is also required if the compressor needs to be replaced or the system needs to be refilled with freon. These procedures are technologically complex and require evacuation of the system, which cannot be done at home without a pump.
Is it worth repairing an old refrigerator?
If the refrigerator is more than 10-12 years old and the compressor needs to be replaced, it is often more economically feasible to purchase new equipment. The cost of a new motor, work and refueling can be up to 70% of the price of a new budget refrigerator.
Timely contacting a specialist will help save money in the long run. A small problem with the relay, solved in time, will not have time to disable an expensive compressor.
Prevention and operating rules
To avoid situations where The refrigerator turns off loudlyit is important to follow the operating rules. Do not allow the chamber to be overloaded with food, as this interferes with air circulation and forces the compressor to work at its limit.
Regularly defrost the refrigerator (if not No Frostand keep the condenser on the back wall clean. Dust and animal hair impair heat transfer, leading to overheating of the motor and frequent activation of the protection.
- 🧹 Cleanliness: every six months, vacuum the condenser grille at the back.
- ⚖️ Load: do not fill the chamber more than 70% for free circulation air.
- 🌡️ Temperature: do not set the minimum values unless necessary, this will wear out the motor.
It is also important to ensure the refrigerator is in the correct position. A housing misalignment can disrupt the operation of the compressor oil system and lead to hydraulic shock. Use a building level when installing equipment.
Following these simple recommendations will extend the life of your refrigerator and ensure quiet, stable operation for many years. Remember that prevention is always cheaper and easier than major repairs.
Why does the refrigerator click but does not turn on?
This is a classic sign of a faulty start relay or compressor. The relay tries to start the engine, a click is heard, but due to a breakdown (motor jamming or winding breakage), the current increases sharply, the protection is activated and the shutdown click is heard again. The cycle repeats.
Is it normal if the refrigerator makes sounds when defrosting?
Yes, in No Frost systems during defrosting you can hear the sounds of dripping water, cracking of plastic from temperature changes and the hum of a fan. However, loud mechanical shocks are not the norm.
Is it possible to use a refrigerator if it clicks loudly?
For a short time, it is possible, but not recommended. Constant clicks mean that the system is in emergency mode. This can lead to burnout of the compressor windings or melting of the wiring, which can lead to a fire.
How much does it cost to replace the start relay?
The cost of the part itself is relatively low, but the price may vary depending on the refrigerator model and brand. The main part of the cost is the work of a diagnostic and replacement technician, as well as a home visit.