The sudden appearance of extraneous sounds in the operation of household appliances always causes concern for the owner. The refrigerator is one of the few devices that works around the clock, ensuring the safety of food, so any failure in its acoustic background cannot be ignored. Most often, users are faced with a situation where the refrigerator clicksbut does not start, or makes periodic knocking noises during operation. Understanding the nature of these sounds allows you to quickly determine whether urgent repairs are required or whether this is a variant of the norm.
The nature of the sound can differ radically depending on the faulty unit. It could be a quiet crack of plastic, a loud metallic clang, or a series of rapid electrical clicks. It is important not to panic, but to listen carefully to where exactly the sound is coming from - from below, from behind or from inside the chamber. Accurate localization of the source of noise This is the first step towards successful diagnosis, which will help save time and money on calling a specialist.
In this article we will analyze in detail all the possible causes of clicking in the refrigerator equipment of various brands, from budget models to premium Side-by-Side systems. You will learn how to distinguish a normal workflow from a critical breakdown, and what actions need to be taken first. Self-diagnosis in some cases allows you to fix the problem without contacting a service center.
Natural sounds: when clicks are the norm
A clicking sound does not always indicate a breakdown of the unit. Modern refrigerators, especially those equipped with the No Frostsystem, have a complex design with many moving elements and sensors. During operation, materials are subject to temperature changes, which leads to their expansion and contraction. It is this physical process that often causes characteristic crackling or clicking noises, which can frighten an inexperienced user.
Such sounds are especially common in new devices or after prolonged defrosting. Plastic parts of the internal lining and metal elements of the evaporator react to changes in temperature conditions. If the clicking noise occurs intermittently and is not accompanied by other symptoms, such as lack of cold or overheating of the compressor, then most likely there is nothing wrong with your refrigerator.
⚠️ Attention: If you just installed a new refrigerator or moved it, let it sit for at least 4-8 hours before turning it on. This is necessary to allow oil to drain into the compressor, which will prevent water hammer and subsequent knocking when starting.
It is also worth considering the operation of automatic systems. For example, in models with electronic control, a quiet click may be heard when modes are switched or the air damper is activated. These sounds are usually quiet, infrequent and do not pose a threat to the functionality of the device. Understanding the physics of processes helps to distinguish operating noise from a malfunction signal.
Problems with the thermostat: diagnosis and symptoms
One of the most common reasons why the refrigerator makes clicking noises and does not turn on is a malfunction of the thermostat (thermostat). This component is responsible for controlling the temperature inside the chamber and sending a signal to start the compressor. When the thermostat fails, it can constantly open and close the circuit, which is accompanied by a characteristic sound, but the engine never starts.
In mechanical models, the thermostat is a device with a bellows and a contact group. Over time, the contacts can oxidize or burn, resulting in a poor connection. When you try to turn on, a click is heard, but no current flows to the motor windings. In electronic models, a temperature sensor is responsible for this function, and if it gives incorrect readings, the control board can block the start of the compressor, while emitting alarm sounds.
Checking the thermostat often requires disassembling the control unit. You need to get to the thermostat mounting point, which is usually located inside the refrigerator compartment or on the back wall. If the refrigerator starts when the wires are shorted to bypass the thermostat, then the problem is in this sensor. Replacing a thermostat is a simple procedure, but requires compliance with safety measures.
How to check a thermostat with a multimeter?
To check, remove the thermostat and put the multimeter in dial mode. At room temperature, the contacts should be closed (unless it is a thermostat with defrost). When placing the sensor in cold water, the contacts should open. Lack of response indicates a malfunction.
It is important to note that ignoring problems with the thermostat can lead to spoilage of food or, conversely, to defrosting of the contents due to continuous operation of the compressor if the contacts “stick” in the closed state. Therefore, timely replacement of this element is critical.
Malfunction of the compressor starting relay
If you hear a series of rapid clicks, followed by a hum, and then again a click and silence, then the starting relay is highly likely to have failed. This small component is responsible for providing a starting pulse to the compressor motor windings. Without this impulse, the motor rotor cannot gain the necessary speed to start working.
Inside the relay there is a coil or posistor, which degrade over time. Mechanical relays can stick, and posistors can lose their properties, ceasing to change resistance when heated. As a result, the compressor tries to start, consuming a huge current, the protection is triggered, opening the circuit (click), and the cycle repeats again. This condition is called “operation in the start-stop cycle.”
Long-term operation of the refrigerator in this mode is extremely dangerous for the compressor itself. The engine does not have time to start, but the windings are already heating up from the starting currents. This can lead to an interturn short circuit and complete combustion of the motor, the replacement of which is not economically feasible. Therefore, when such symptoms appear, it is necessary to immediately de-energize the device.
⚠️ Attention: Do not try to revive the old starting relay by tapping or heating. This is a temporary measure that can lead to a fire in the wiring due to broken contact connections. Replace the part with a new one that matches the model of your compressor.
Replacing the start relay usually does not require special tools and skills. It is enough to remove the back cover of the refrigerator, disconnect the wiring block and replace the unit. The main thing is to choose a relay with similar characteristics, since there are no universal solutions for all types of compressors.
☑️ Diagnostics of the starting relay
Why does the inverter refrigerator click
Owners of modern equipment with the system No Frost and inverter compressors may encounter other types of sounds. Inverter motors operate on the principle of smoothly changing rotation speed, so classic start-up clicks are not typical for them. However, the presence of electronics makes its own adjustments to the acoustic profile of the device.
Clicks in such models are often associated with the operation of dampers that regulate the flow of cold air between the chambers, or with the defrost system valves. The electronics periodically open and close the dampers to maintain the set temperature, which is accompanied by a quiet mechanical sound. Also, the source of noise may be the inverter control unit itself, located next to the compressor.
It is worth noting that inverter compressors are more sensitive to voltage changes in the network. If there are surges in your electrical network, the control unit may go into protection, making a characteristic sound. Unlike conventional relays, diagnostics here require the use of special equipment to read error codes.
The table below will help you quickly navigate the types of sounds and their possible causes depending on the type of refrigerator:
| Sound type | Probable cause | Type refrigerator | Repair urgency |
|---|---|---|---|
| Single loud click | Thermostat or thermal expansion | Any | Low |
| Series clicks, humming | Start relay or compressor | Normal (Linear) | High |
| Quiet crackling, rustling | No Frost system, fan | No Frost | Medium |
| Clicking and blinking indicators | Electronics error, power surge | Inverter | High |
Compressor knock: water hammer and wear
The most unpleasant scenario is when clicks and knocks come directly from the compressor. If you hear a strong metallic thud followed by vibration upon startup, this may indicate a problem. This happens if liquid refrigerant or oil enters the compressor cylinder at a time when the piston has already begun to move. The liquid does not compress, which leads to shock. water hammer. This happens if liquid refrigerant or oil enters the compressor cylinder at a time when the piston has already begun to move. The fluid does not compress, causing shock.
Often the cause of water hammer is improper transportation of the refrigerator. If the device was transported lying on its side, oil could leak into the system circuit. That is why manufacturers insist on vertical transportation and long-term settling before switching on. Also, the cause may be excessive freon charging or a malfunction of the capillary tube.
Another reason for knocking is wear of the internal mechanical parts of the compressor (bearings, piston group). Over time, the gaps increase and the parts begin to hit each other. This is accompanied by increasing noise and decreased cooling efficiency. In such cases, repairing the compressor is impossible; it must be completely replaced.
⚠️ Attention: If you hear loud metallic knocks inside the compressor, immediately unplug the device. Further work will lead to the destruction of the internal valves and the release of oil into the system, which will require expensive flushing of the entire circuit.
It is difficult to diagnose a problem with the compressor yourself, since it requires measuring the pressure in the system and analyzing the gas composition. However, if you notice that the refrigerator has stopped freezing, and the compressor is knocking and vibrating, get ready to call a technician.
The influence of incorrect installation on the noise level
Sometimes the cause of clicks and vibrations lies not in the breakdown of parts, but in a simply incorrect installation of the unit. If the refrigerator is not level, one of the legs may not touch the floor, or the body may be askew. As a result, when the compressor operates, resonant vibrations occur, which are transmitted to the shelves, drawers and even the walls of the room, intensifying and turning into an obsessive knocking.
In addition, it is important to maintain the gaps between the back wall of the refrigerator and the wall of the room. If the device is moved too close, air circulation is disrupted, the condenser overheats, and the compressor is forced to work with increased load. This may cause additional noise and shorten the life of the equipment.
Also check that the internal shelves or products do not touch the walls of the chamber. Sometimes just adjusting the bottle is enough to make the annoying sound disappear. Make sure all shipping bolts and fasteners have been removed after unpacking.
Use a spirit level to eliminate noise caused by installation. Adjust the height of the legs until the bubbles of the level are exactly in the center. This will ensure a stable position and proper closing of the doors.
Frequently asked questions (FAQ)
Why does the refrigerator click but does not freeze?
This is a classic sign of a faulty start relay or thermostat. The compressor tries to start (clicking) but does not receive the required impulse or voltage, so no cooling occurs. Diagnostics of the electrical circuit is required.
Is it dangerous to ignore clicks in a new refrigerator?
In the first days of operation, sounds of thermal expansion (expansion of materials) are possible. If the clicking sounds are not accompanied by a lack of cold or a burning smell, this is normal. However, if the sound is similar to an electrical discharge or a metallic knock, it is better to call a technician.
Is it possible to replace the start relay yourself?
Yes, if you have basic skills in working with tools. The main thing is to buy a relay of the exact same model as the one you had, since the starting current parameters differ for different compressors.
How often do you need to defrost the refrigerator to avoid knocking?
Refrigerators with the No Frost system do not require manual defrosting. Conventional models (“crying evaporator”) are recommended to be defrosted as ice forms, but at least once every 6-12 months for prevention.
Does the refrigerator click during power surges?
Yes, protective electronics can make clicks when trying to protect against unstable voltage. In regions with poor power supply, it is recommended to use a voltage stabilizer or surge protector.