The situation when extraneous sounds are heard when the refrigerator is operating always causes concern for the owner. Especially if these sounds are accompanied by periodic clicks, which can be quiet or quite loud. It is important to understand that not all sounds indicate a breakdown, but you should not ignore them.
In normal operation, modern equipment should operate almost silently, emitting only a quiet hum of a running motor. If you hear that the unit clicks, but the cold inside remains, this may be a sign of either a harmless process or a serious malfunction of the electrical circuit.
In this article we will analyze in detail the main reasons for the occurrence of clicks, diagnose the main components and determine when a technician’s intervention is required, and with than you can handle on your own. If clicks are accompanied by a lack of cooling, operation should be stopped immediately.
Natural sounds and thermostat operation
The first thing that must be excluded during diagnosis is natural physical processes. Old models and some modern units use mechanical thermostat. Its operation is based on opening and closing contacts when the temperature inside the chamber changes. When the temperature reaches a predetermined threshold, the bimetallic plate inside the thermostat suddenly changes its shape, emitting a characteristic click.
This sound means that the compressor has either turned on or off. If the click is heard when the motor stops or immediately after it starts, and a normal temperature is maintained inside the refrigerator, then there is nothing to worry about. This is normal operation mechanical regulator.
However, if the clicks become very frequent, rhythmic and repeat every few minutes, this may indicate that the thermostat is “stuck” or has failed. In this case, the compressor may try to start, but immediately stall, or, conversely, not turn off for a long time. To check, you can try to slightly turn the temperature control knob in different directions - the sound should change or disappear.
⚠️ Attention: If the thermostat clicks become too loud and sharp, it is possible that the internal spring of the mechanism has weakened or, conversely, is overtightened, which requires replacing the unit.
It is also worth considering thermal expansion materials. The plastic of the internal walls and metal elements of the evaporator may make cracking or light clicking noises when the temperature changes sharply. This is absolutely normal, especially after loading a large amount of warm food or defrosting.
Starting relay: the main source of the problem
The most likely cause of loud clicks when trying to start the refrigerator is a malfunction of the starting relay. This small but critical element is responsible for supplying a starting pulse to the compressor motor winding. If start relay failed, the motor cannot start, and you hear a series of rapid clicks, followed by a humming sound and then dying down.
The process looks like this: the relay supplies current, there is a click, the compressor hums, but does not start. After a few seconds, the thermal protection is triggered and a second click is heard - shutdown. The cycle is repeated until the refrigerator is de-energized. In such a situation, operation of the equipment is impossible and dangerous for the compressor itself.
Often the cause of the breakdown is burning of the contacts inside the relay or destruction of the starting element (posistor or capacitor, depending on the design). Visually, traces of soot, melted plastic, or cracks in the housing may be visible on a faulty relay. For accurate diagnostics, the device must be removed and “ringed” with a multimeter.
How to check the starting relay with a multimeter?
To check the relay, you need to disconnect it from the compressor and contacts. Switch the multimeter to resistance (ohms) measurement mode. The probes are applied to the relay contacts. If the resistance tends to infinity, the circuit is broken, if it approaches zero, there is a short circuit. In both cases, the relay must be replaced. You can also shake the relay: if you hear a ringing inside, it means the mechanical part is damaged.
Replacing the start relay is one of the simplest procedures in repairing refrigerators. It requires no special equipment other than a screwdriver and possibly pliers. The main thing is to purchase a part with exactly the same markings as the burnt one, since the starting current parameters differ for different compressor models.
Compressor: diagnostics and symptoms of malfunction
If the relay is working properly and the clicking continues, the problem may lie in the very heart of the refrigerator - compressor. The engine may click if its internal mechanical parts are seized. In this case, the rotor tries to turn, but due to lack of lubrication or mechanical damage to the piston group, an impact occurs, which we hear as a click.
Another alarming symptom is when the compressor hums, but does not start, and then a click is heard when the protection is turned off. This may indicate an interturn short circuit in the motor windings. In such a situation, the current increases sharply, the thermal relay trips and breaks the circuit. Repeated starting attempts in this case are strictly prohibited, as they can lead to complete combustion of the motor.
It is better to entrust compressor diagnostics to professionals, since it requires checking the winding resistance and pressure in the system. However, an initial visual inspection can be carried out independently. Pay attention to the condition of the motor housing: is there any oil leakage, strong vibration or a characteristic burning smell.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Single click when stopping | Thermostat operation | Normal, no repair required |
| Series of clicks, the motor does not start | Faulty start relay | Replacing the relay |
| Humming, clicking, very hot motor | Compressor jammed | Call a technician, replace the compressor |
| Clicks without buzzing, no cold | Open circuit or burnt out motor | Electrical diagnostics |
Problems with wiring and contacts
Sometimes the sound source lies not in the mechanics, but in the electrical connections. Loose contacts, oxidized terminals or frayed wires can cause sparking, which is accompanied by a characteristic crackling or clicking sound. This is especially true for refrigerators that have been in use for a long time or were subject to vibration during transportation.
Particular attention should be paid to the location where the power cable is connected to the terminal box on the rear wall of the unit. If the contact is poor, heating and micro-discharges may occur at the junction. This not only causes noise, but also poses a real fire hazard. If you find blackened insulation or melted plastic, you must immediately replace the damaged area.
It is also worth checking the integrity of the grounding. The lack of high-quality grounding can lead to the accumulation of static electricity on the housing, the discharge of which can also be accompanied by sound effects, although this occurs less frequently.
⚠️ Attention: Carry out any work with electrical wiring only with the device completely disconnected from the network. Do not touch live parts.
If you notice that clicks are coming from the control panel area (in models with electronics), this may indicate a faulty control board. In modern models electronic modules they control the start of the compressor through triacs or relays on the board. Clicks in this case may mean the board is trying to start the motor or the internal protection is triggered.
The influence of the No Frost and defrosting system
Owners of refrigerators with the system No Frost often encounter clicks that are associated with the operation of the automatic defrosting system. In these units, the heating element (heating element) is periodically turned on, which melts the ice on the evaporator. The process of transition from cooling mode to defrost mode and back is accompanied by the operation of various valves and switches.
The clicking sound in this case is produced by a defrost sensor or an air damper that regulates the flow of cold air. If the damper is stuck or its actuator is faulty, it may make a rhythmic knocking noise as it tries to close or open. This often happens when the mechanism freezes.
In addition, in No Frost refrigerators, the sound may come from the fan. If ice forms on the fan blades or a foreign object gets there, it can touch the walls, creating a cracking noise that can easily be confused with an electrical click. To check, you need to defrost the refrigerator for 24 hours and check the cleanliness of the air ducts.
☑️ Diagnostics of the No Frost system
When you need to call a technician
Despite the possibility of self-diagnosis of some components, there are situations when you cannot do without a qualified specialist. If after replacing the start relay the problem does not disappear, or you do not have experience working with electrical appliances, it is better not to take risks. Professional repairs are often cheaper than buying a new refrigerator to replace a damaged one.
A call to a technician is required if the clicks are accompanied by the smell of burnt wiring, strong heating of the compressor housing (to the point where it is impossible to hold your hand for more than 2-3 seconds) or if the refrigerator has stopped freezing. In these cases, we are talking about a complex malfunction that requires special equipment for diagnosing and vacuuming the system.
It is also worth contacting service if the refrigerator is under warranty. Opening seals on your own and attempting repairs may result in loss of warranty. The service center technician will carry out diagnostics free of charge and replace faulty components at the manufacturer's expense.
⚠️ Attention: If you smell gas (refrigerators use freon), immediately ventilate the room and do not turn on electrical appliances. Although the freon itself usually does not smell, the smell can come from the oil from the compressor or the insulation of the wires.
Prevention and operating rules
To extend the life of the refrigerator and avoid the appearance of extraneous sounds, you must follow simple operating rules. First of all, ensure stable voltage in the network. Voltage surges are detrimental to electronics and compressor windings. It is recommended to use a surge protector or voltage stabilizer, especially in houses with wiring.
Regular defrosting (for drip systems) and cleaning the capacitor from dust will also help avoid overloads. Dust on the radiator grille at the back of the refrigerator impairs heat transfer, causing the compressor to work longer and harder, which shortens its life. Wipe the grill with a soft brush or vacuum it every six months.
Do not put hot food in the refrigerator. A sharp jump in temperature forces the thermostat and compressor to work in extreme mode, which can lead to early wear of the thermostat and the appearance of clicks. Allow food to cool to room temperature before storing.
Following these simple guidelines will keep your refrigerator running quietly and efficiently for many years. Remember that timely detection and elimination of minor faults prevents major breakdowns.
Why does the refrigerator click but does not freeze?
If you hear clicks, but no cold is produced, most likely the compressor does not start. This may be caused by a burnt-out start relay, a malfunction of the compressor itself (jamming, broken windings) or a broken thermostat that does not give the start command. A freon leak is also possible, during which the pressure in the system drops and the protective relay turns off the motor.
Is it possible to operate the refrigerator if it clicks?
If the clicks are rare and are associated with the operation of the thermostat, and there is cold inside, then you can. If the clicks are frequent, accompanied by attempts to start the engine (humming) and lack of cold, operation should be discontinued. Constant attempts to start can permanently damage the compressor or lead to a wiring fire.
How much does it cost to replace the start relay?
The cost of the relay itself is usually low and depends on the model of the refrigerator (from 500 to 2000 rubles). However, if you call a specialist, the cost of labor and travel will be added to the cost of the part. Replacing it yourself will only cost the price of the part if you have the skills and tools.
How to distinguish the sound of a thermostat from the sound of a relay?
The sound of a thermostat is usually single, dull and heard less frequently (every 30-60 minutes or less, depending on the setting). The sound of a faulty relay is a series of frequent clicks (every 3-10 seconds) when trying to start, often accompanied by a humming motor.