The situation when the refrigerator makes loud clicks instead of the usual humming often takes you by surprise. This sound can be one-time and quiet, or it can be repeated with frightening frequency, accompanied by a complete loss of cold inside the chambers. For the owner of household appliances, this is a signal that there is a failure in the refrigerant circulation system or electrical circuit that requires immediate attention. Ignoring the problem can lead to overheating of the motor windings and expensive repairs.
In most cases, a characteristic knock is produced by start relay, which is trying to start the compressor, but encounters resistance or overload. The mechanism operates, breaking the circuit, and after a while the cycle repeats. However, it is not always the electrics that are the source of noise; Sometimes extraneous sounds can be produced by structural elements vibrating from the operation of the motor, or even by itself compressor in the presence of mechanical defects. Understanding the nature of sound is the first step to successful repair.
In this article we will analyze in detail the physics of the processes occurring inside the refrigeration unit and will help determine whether the fault can be fixed on your own or whether you will need to call a technician. It is important not to panic, but to consistently check the main components. Independent opening of a sealed circuit without special equipment is strictly prohibited and can be life-threatening. We will focus on safe diagnostic methods available at home.
Operation principle of the starting relay and mechanism click
To understand the cause of the noise, you need to understand the design of the starting system. The main element responsible for turning on the engine is the starting relay. This is a small device mounted on the compressor housing. The moment the refrigerator is turned on, the relay delivers a powerful impulse to the starting winding, helping the piston group overcome inertia and start moving.
As soon as the engine rotor reaches the required speed, the current in the circuit drops, and the relay should open the contacts, turning off the starting winding. If the engine does not start, the current remains high, and the thermal relay forcibly breaks the circuit to prevent the windings from burning out. It is this opening process that is accompanied by the characteristic sound that we hear.
Modern models often use PTC relay (posistors), which operate silently and have no moving parts, unlike older induction models with a coil. However, even they can fail. If the relay is working properly, the on and off cycle is silent or with a barely noticeable click. A loud, ringing knock often indicates that the mechanism is “stuck” or the contacts are burnt.
⚠️ Attention: Before any manipulations with electrical components, be sure to unplug the refrigerator. Residual voltage in capacitors can be dangerous, and working with a plugged-in device without electrical safety skills is unacceptable.
The frequency of repetition of clicks is also important for diagnosis. If the sound occurs every few minutes, this indicates that the thermal release is working, which protects the motor from overheating. In normal operation, such cycles should occur much less frequently, only after a long period of inactivity or defrosting.
Malfunctions of the starting relay as the main cause
The most likely culprit of the problem is the starting relay. Over time, the internal contacts oxidize, and the plastic case may become deformed from constant heat. In induction relays, the coil often wears out or the core jams, which is why it cannot return to its original position or, conversely, turns off the power too quickly.
Checking the relay can be done visually and using a multimeter. Remove the protective cover from the back of the refrigerator and carefully disconnect the relay from the compressor. Shake the device: if a rattling sound is heard inside, it means that the internal elements are damaged and require replacement. This is the easiest method of initial diagnosis.
- 🔌 Oxidation of contacts: leads to poor connection, sparking and heating, which causes clicks and eventual failure.
- 🔥 Overheating of the posistor: in a PTC relay, the ceramic element may lose its properties and not provide the required resistance jump.
- 🧊 Start attempt: the relay clicks, trying to start the compressor, but due to a breakdown, the motor does not start, and the cycle repeats.
If you find that the relay has traces of burning, melting or mechanical damage, it must be replaced. Fortunately, this is one of the most affordable spare parts. When purchasing, pay attention to the markings, since different models Indesit, Atlant or LG use different types of relays that are not always compatible with each other.
It is also important to check the condition of the contacts on the compressor itself. If they are blackened or covered with soot, they should be carefully cleaned, although in most cases it is easier and more reliable to replace the entire assembly. A faulty relay is not just noise, it is a risk of completely “killing” an expensive compressor.
Problems with the compressor: jamming and interturn short circuit
If replacing the relay did not help, or the clicking continues even with a new device, the problem may lie deeper - in the very “heart” of the refrigerator, the compressor. The motor may be mechanically or electrically faulty. In the first case, the piston group jams, in the second, a breakdown of the winding insulation occurs.
When the piston is pressed, the motor hums, tries to turn over, but cannot, after which the relay turns off the power with a click. This often happens after a long period of inactivity or if there is stagnation in the oil circulation system. Sometimes it is possible to “unwedge” the compressor by applying voltage directly to the starting winding, but this requires skills and special equipment. jamming The piston motor hums, tries to turn over, but cannot, after which the relay turns off the power with a click. This often happens after a long period of inactivity or if there is stagnation in the oil circulation system. Sometimes it is possible to “unwedge” the compressor by applying voltage directly to the starting winding, but this requires skills and special equipment.
In the case of turn-to-turn short circuit the resistance of the windings drops, the current increases sharply, and thermal protection is triggered almost instantly. You hear a startup click, a short hum, and then a shutdown click again. You can check the windings with a multimeter by measuring the resistance between the contacts. Normal values are usually from 10 to 30 Ohms for the working winding and slightly higher for the starting winding, but the exact data depends on the model.
| Symptom | Possible cause | Character sound | Solution |
|---|---|---|---|
| Click, silence, repeat after 2-5 minutes | Faulty starting relay | Loud metallic click | Replacement relay |
| Humming, clicking, case heating | Compressor jamming | Low humming + clicking | Attempt to wedge or replacement |
| Short click, no humming | Open circuit or burnt winding | Quiet click | Diagnostics with a multimeter |
| Series of clicks during operation | Deformation of the housing or tubes | Crackling sound similar to clicks | Checking fasteners |
Is it possible to restore a jammed compressor?
In some cases, craftsmen use the method of “tapping” the housing with a hammer through a wooden gasket during an attempt to start. This may help get the pistons moving. However, success is not always guaranteed, and often this is only a temporary measure before replacing the unit.
If diagnostics show a compressor malfunction, repair at home is almost impossible. The unit needs to be replaced, freon pumped out and the system evacuated. This is a complex procedure that requires licensed equipment and skills.
The influence of voltage drops and wiring
Unstable voltage in the electrical network is the scourge of old wiring and holiday villages. If the voltage drops below the acceptable level (usually below 190-200 Volts), the compressor does not have enough power to start. The starting relay is triggered, the motor begins to hum, but does not spin, the current increases, and the protection turns off the system with a click.
Continuous work in such conditions quickly disables equipment. The windings overheat, the insulation is destroyed, and the compressor burns out. To protect expensive equipment, it is recommended to use voltage stabilizers or voltage control relays, which will turn off the device during dangerous surges.
- ⚡ Low voltage: there is not enough power to start, the relay turns on and off cyclically.
- 🔌 Poor contact in the socket: sparking and voltage drop can simulate symptoms of a breakdown relay.
- 📉 Jumps in the network: sudden changes in current parameters cause the protective mechanisms to operate in emergency mode.
Check whether the plug or socket is heating up. If you smell melted plastic or see soot, the problem lies with the apartment's electrical wiring, not the refrigerator. In this case, using the device is dangerous and requires calling an electrician.
Thermal deformation and external factors
Clicks do not always indicate a breakdown. Sometimes the refrigerator clicks due to the physical processes of expansion and contraction of materials. The plastic case, internal shelves and even metal evaporator tubes can change their size with temperature changes, making sounds similar to clicks or crackling.
This is especially often observed in refrigerators with a system No Frost during automatic defrost cycles. The heating element heats the evaporator, the ice melts, and the structures “move.” If clicks are heard rarely and are not accompanied by loss of cold, most likely this is normal.
However, if the sound has become intrusive, it is worth checking:
- 📏 Fixing the shelves: loose clamps may rattle due to vibration of the compressor.
- ❄️ Ice: a thick layer of ice on the evaporator can crack when pieces break off.
- 🥣 Cookware inside: glass jars or bottles, when touching, can ring and click from vibration.
⚠️ Attention: If the clicks are accompanied by a burning smell, smoke or strong heating of the housing near the motor, immediately unplug the device. Continued operation may result in a fire.
It is also worth paying attention to how the refrigerator is installed. If it is not level, the vibration of the running motor can be transmitted to the floor or walls, causing resonance and extraneous sounds. Adjusting the legs will help eliminate this effect.
Self-diagnosis algorithm
Before calling a technician, you can carry out a number of simple steps that will help narrow down the troubleshooting area. This will save time and money, as you can accurately describe the symptoms to a specialist, or perhaps solve the problem yourself.
Start with a visual inspection and listening. Turn off the refrigerator, wait 10-15 minutes, then turn it on again. Stand at the back of the engine compartment. If you hear a click, followed by a hum that lasts 3-5 seconds, and then a click again, the problem is in the start relay or compressor.
☑️ Diagnostics of clicks
If you have a multimeter, test the compressor windings. The resistance between the common contact and the working one, as well as between the common and the starting contact, should be within the normal range (usually 10-50 Ohms). If the device shows infinity (open circuit) or zero (short circuit), the compressor is faulty.
It is also important to check whether the condenser (radiator at the back) is clogged with dust. Overheating due to poor ventilation causes the thermal release to operate more often, which may be accompanied by clicking noises. Regular cleaning of the back wall is a good preventive measure.
When you need to call a specialist
Despite the possibility of self-diagnosis, there are situations when you cannot do without a professional. Replacing a compressor, filling with freon, removing blockages in a capillary tube are jobs that require special tools and a license to work with refrigerants.
If you are not confident in your abilities when working with electricity, it is better not to take risks. An error when connecting the windings can lead to instantaneous burnout of the new relay or the motor itself. The technician will conduct a full diagnostic, including measuring the pressure in the system and current consumption.
In addition, modern electronically controlled refrigerators can display error codes on the display that will indicate a specific unit. It can be difficult to decipher these codes without the manufacturer's service documentation (for example, Bosch, Samsung, Whirlpool).
Is it possible to temporarily use the refrigerator if it clicks?
It is not recommended to use the device with a faulty start relay or compressor. Cyclic starting attempts overheat the windings, which can lead to a fire or permanent failure of the motor. If the clicks are caused by deformation of the plastic and there is cold, operation is possible.
How much does it cost to replace the start relay?
The cost of the relay itself is usually low (from 500 to 2000 rubles depending on the model), but the work of a repairman and diagnostics can cost more. In some cases, it is more advisable to call a specialist than to buy tools for self-repair.
Why does a new refrigerator click?
New refrigerators may click due to deformation of plastic parts during the first cooling/heating cycles. It is also possible that the relay is factory defective. If the clicks are loud and frequent, file a warranty claim.
How to extend the life of the compressor?
Regularly defrost the refrigerator (if there is no Frost), do not put hot foods, provide a gap at the back wall for ventilation and use a voltage stabilizer. Do not turn on the device immediately after defrosting - let it stand for 2-3 hours.
The myth of knocking fingers
There is an opinion that if you knock on the compressor housing, it will start. This only works in cases of slight piston seizure and only helps temporarily. Constant “impact treatment” will completely kill the motor.