A sudden foreign sound in the operation of household appliances always causes alarm, especially when We are talking about a refrigerator that should work quietly and inconspicuously. If you notice that refrigerator clicking, this may be either a sign of the normal functioning of some components, or a harbinger of a serious breakdown that requires immediate attention. The nature of the sound, the frequency of its repetition and accompanying symptoms (for example, a lack of cold or a running fan) are key factors for the initial diagnosis.
In this article we will examine in detail the physical causes of clicking in various cooling systems, from thermostat operation to compressor problems. Understanding the nature of the sound will help you make the right decision: leave the unit alone, try to fix the problem yourself, or call a repairman. A sharp metallic clanging sound at startup, accompanied by a hum, often indicates that the motor-compressor is jammed, which requires immediate disconnection of the device from the network to avoid a fire.
Physiological noises: when there are clicks normal
You should not immediately panic when you hear a strange sound, since modern refrigerators, especially No Frost systems, make a lot of sounds during operation. Thermoregulator (the thermostat) makes a characteristic loud click when the compressor is turned on or off. This occurs due to the opening or closing of electrical contacts inside the sensor, which responds to changes in temperature in the chamber. If the click is heard once before starting the motor or immediately after it stops, and the refrigerator continues to freeze as usual, then this is an absolutely normal situation.
Another reason may be sounds made by the refrigerant itself or the body materials. As freon passes through the evaporator tubes, gurgling sounds or quiet clicks may occur due to pressure changes. In addition, plastic of the internal chamber plating parts can react to temperature changes by expanding or contracting, producing a cracking sound. This is especially often observed in new models or after defrosting, when temperature changes are most dramatic.
In models with the No Frost system, the fan plays an active role. If ice forms on the blades or in the rotation mechanism, the fan may hit it, making rhythmic clicks or crackles. This usually happens cyclically: while the fan is running, there is sound, when it stops (during defrosting) there is silence. You can check this by opening the door of the refrigerator or freezer (depending on where the fan is located): if the sound disappears when the door is open, then the problem lies in the blowing system or ice on the evaporator.
⚠️ Attention: If the clicks are accompanied by a burning smell, smoke or strong heating of the back wall, immediately disconnect the appliance from the power supply. Operation of such a device is dangerous to life and property.
Problems with the start relay and compressor
The most common and serious reason why the refrigerator clicks and does not turn on is a malfunction starting relay. This small element is responsible for starting the compressor engine. Inside the relay there is a coil and a movable core; when voltage is applied, the core retracts, closing the contacts and starting the motor. If the mechanism is worn or dirty, the core may not go all the way, making a series of rapid clicks, after which the compressor hums for a few seconds and stalls. This mode of operation is called “pedaling”, and it is extremely harmful to the motor windings.
Another option is a breakdown of the compressor itself. If the motor-compressor is mechanically jammed (for example, due to exhaustion of the piston group or lack of lubrication), it will not be able to start. The start relay will try to turn it on, making a loud clicking noise, the motor will hum (try to move), and then the safety relay will cut off the power to prevent the windings from burning out. This cycle can be repeated endlessly: click - hum - silence - click. In such a situation, independent repair is practically impossible; replacement of the unit is required.
You can often diagnose a problem with the relay visually and by ear. If you hear a series of clicks at intervals of 10-20 seconds, and at this moment the refrigerator is not freezing, but the rear grill remains cold, most likely the starter circuit is not closing. Sometimes lightly tapping the relay body (with the refrigerator unplugged) helps to shake off any dust or oxides, but this is a temporary measure. The safest way is to replace the relay with a new one, choosing an analogue according to the marking.
Faults of the thermostat and sensors
Thermostat - this is the "brain" that decides when to turn on the cooling. If its contacts are burnt or oxidized, they may not provide a reliable connection. In this case, you may hear frequent clicking or cracking noises as the refrigerator tries to start, but the circuit keeps breaking. Mechanical thermostats have a bellows tube containing gas or liquid inside; if it is damaged or has lost its seal, the device stops responding correctly to temperature, which leads to chaotic switching on and clicking.
In modern models with electronic control, the role of a thermostat is performed temperature sensors (thermistors). They do not click on their own, but their failure results in erroneous commands to the control board. The board, receiving incorrect data (for example, that the temperature has already been reached, although it is warm in the chamber, or vice versa), may constantly try to start the compressor or, conversely, block it, which is accompanied by clicks of the control relays on the module. Diagnostics in this case requires a multimeter to check the resistance of the sensors.
Symptoms of a malfunctioning thermostat are often similar to relay problems, but there is a difference: with a bad thermostat, the compressor may not try to start at all, or, conversely, work non-stop until the protection is triggered. If you hear a click, but the compressor does not even hum, the problem most likely lies in the control circuit or the sensor itself, which does not send a signal to start.
How to check the thermostat without instruments?
Remove the thermostat and immerse its sensitive tube in cold water with ice. Close the contacts with a multimeter or light bulb. If, during cooling, a click and the circuit does not close, the thermostat is faulty and requires replacement.
The influence of the No Frost system and ice freezing
Owners of refrigerators with the system No Frost often encounter clicks associated with the operation of the defrost system. Behind the evaporator there is a heating element (heating element), which is turned on on a timer to melt the ice. When the heating element is turned on or off, a click may also be heard from the thermostat or defrost timer. This is normal, but if the sound becomes loud or is accompanied by the smell of burning insulation, it means that the heating element is breaking through to the housing or is overheated.
A common problem is ice freezing on the fan. If the defrost system does not work correctly (the heating element is burnt out, the timer or defrost sensor is faulty), a “fur coat” grows on the evaporator. The fan located nearby begins to touch the ice build-up with its blades. This causes a rhythmic cracking or knocking noise that may wax or wane. Over time, this can cause the fan motor to fail or the blades to break. To eliminate it, you need to defrost the refrigerator (turn it off for 10-12 hours with the doors open) and check the defrosting system.
It is also worth checking the drainage system. If the meltwater drain hole is clogged with debris or ice, the water can accumulate and freeze, forming ice plugs. When the compressor is running, vibration can cause movement of these ice masses, which can also be heard as tapping or clicking inside the chamber or behind the back panel.
☑️ Checking the No Frost system
Diagnostic table: determine the cause by sound
To more accurately determine the malfunction, you can use the following table, comparing the nature of the sound with a possible diagnosis. This will help you formulate the problem when calling a technician or when searching for a spare part.
| Sound character | Associated symptoms | Probable cause | Difficulty of repair |
|---|---|---|---|
| Single ringing click | The refrigerator turns on/off, freezes normally | Thermostat operation (normal) | No repair required |
| Series of quick clicks, buzzing for 5-10 seconds | The refrigerator does not freeze, the compressor is hot | Faulty start relay or compressor | Medium (relay replacement) |
| Rhythmic crackling/knocking | Sound intensifies when closing the door or working | The fan touches ice or a foreign object | Low (defrosting) / Medium |
| Quiet crackling of plastic | No other symptoms, occurs after loading products | Thermal expansion of materials | Normal |
| Click and complete silence | The compressor does not start, there is no light in the chamber (or there is) | Open circuit, thermostat malfunction or boards | High (diagnostics needed) |
It is important to understand that diagnostics by sound is only the primary stage. An accurate diagnosis can only be made by a specialist using special tools. For example, interturn short circuit in the compressor windings can give similar symptoms to a relay failure, but requires replacement of the entire unit.
Mechanical reasons and foreign objects
Sometimes the reason is trivial and lies not in internal nodes, but in the external environment. The vibration of a running compressor is transmitted to the housing and can cause resonance with nearby objects. Check that the refrigerator is not touching a wall, furniture, or objects standing on it. Even a light touch can turn a quiet vibration into a loud knock or click. Also check the adjustable feet: if the refrigerator is unstable, it may “play” and make sounds.
Inside the chambers, glass shelves or dishes can become a source of sound. If the shelf is not installed tightly in the grooves, vibration may cause it to bounce and hit the walls. Remove all food and utensils to eliminate their influence. Inspect the fastenings of shelves and drawers - sometimes plastic rubs against plastic, producing a creaking sound that is heard as clicks.
⚠️ Attention: Do not try to disassemble the sealed circuit (pipes with freon) or open the compressor yourself. The refrigerant is under pressure, and its leak will not only stop the refrigerator, but can also be dangerous if it comes into contact with an open fire.
When you need to call a specialist
There are a number of situations where independent actions can only aggravate the situation. If after defrosting (which lasted at least 12 hours) the refrigerator continues to click and does not turn on, the problem is of a technical nature. You also need the help of a specialist if you hear the smell of burnt wiring, see sparking, or if the compressor operates continuously without turning off and without gaining temperature.
Replacing a compressor, sealing tubes, evacuation of the system and filling with freon are complex technological processes that require special equipment (vacuum pump, pressure gauge station, burner). Trying to implement this at home without experience and tools means risking complete breakdown of the unit. In such cases, it is more economically feasible to contact a service center.
Prevention and proper care
To minimize the risk of problems with sound and When starting, it is important to follow the operating rules. Defrost the refrigerator regularly (if it is not No Frost), keep the condenser grill at the back clean - dust and animal hair worsen heat transfer, causing the compressor to work with overload, which reduces its life. Also, do not place the refrigerator close to the wall, ensuring ventilation of the motor.
Periodically check the door seals. If they do not fit tightly, warm air enters the chamber, humidity increases, and the No Frost system does not have time to remove moisture, which leads to ice accumulation and problems with the fan. Wipe the rubber bands with a soft cloth and, if necessary, lubricate them with silicone oil for elasticity.
The secret of quiet operation
Make sure that the floor on which the refrigerator stands is level. Even a slight misalignment causes an uneven load on the compressor and increases vibration, accelerating wear of parts.
Frequently asked questions (FAQ)
Why does the refrigerator click immediately after I plug it in?
When you first turn it on, the thermostat is in the "on" position, and it immediately gives a signal to start. The click is the activation of the thermostat or start relay contacts. If after the click the compressor hums and starts, everything is fine. If it clicks repeatedly and stalls, there is a problem with the relay or compressor.
Can a new refrigerator click?
Yes, new refrigerators often make more sounds. This is due to the fact that the parts have not yet gotten used to it, the plastic is experiencing thermal deformation, and the refrigerant is actively circulating through the system. Usually, after 1-2 weeks of operation, the background noise decreases.
Is it dangerous to ignore clicks if the refrigerator is freezing?
If the clicks are rare (only when turning on/off) and there is cold, it is not dangerous. But if the clicks are frequent, rhythmic and accompanied by a hum, ignoring them can lead to the combustion of the compressor, the replacement of which is expensive.
How to extend the life of the compressor if it starts to click?
Ensure good ventilation at the back, move the refrigerator away from the wall, clean the grill from dust. If the problem is in the relay, replace it as soon as possible so that the motor does not work in constant starting mode.