The situation when something clicks in the refrigerator is familiar to many owners of household appliances. This sound can be barely noticeable or loud, frightening, interrupting the silence of the night. Often clicks are accompanied by the fact that the unit does not start cooling, although the light inside is on. In other cases, the equipment continues to freeze, but extraneous noise signals an incipient malfunction.
Such signals cannot be ignored, since constant clicking they often indicate an attempt to start the compressor, which for some reason cannot start working. This leads to overload of the electrical network and wear of the starting equipment. Understanding the nature of sound is the first step to preserving products and the budget allocated for repairs.
In this article we will analyze in detail the mechanical and electrical causes of knocking. We will look at when you can handle it yourself, and in which cases you need to call a specialist. We will also touch on the topic of normal operation equipment so that you do not panic unnecessarily.
Natural sounds: when clicks are the norm
Not every sound coming from kitchen appliances is a sign of a breakdown. Modern refrigerators, especially models with the No Frostsystem, are equipped with many automatic valves and switches. During their normal operation, they can make sounds reminiscent of light blows or crackling of plastic.
For example, when the door is opened, a light sensor or a magnetic reed switch may be triggered, producing a quiet click. Air also circulates in the chambers, and due to temperature differences, the plastic parts of the case or trays may be slightly deformed. This phenomenon is called thermal expansion. It usually manifests itself in the form of periodic crackling, especially after the first load of food or defrosting.
Another reason for natural noise is the operation of the compressor. When it is turned on or off, a redistribution of the refrigerant in the tubes may occur, which is sometimes accompanied by gurgling and single knocks. If the refrigerator freezes well, and the clicks are rare and quiet, most likely, everything is in order with your equipment.
- 🔹 A quiet click when opening the door - this is the light switch.
- 🔹 Periodic crackling of plastic - the reaction of materials to a change in temperature.
- 🔹 Single clicks when starting the engine are normal hydraulics of the system.
⚠️ Attention: If clicks are accompanied by a burning smell, sparking or smoke, immediately unplug the device. These are signs of a short circuit or overheating of the wiring.
Malfunction of the compressor start relay
The most common reason why something clicks in the refrigerator, but it does not turn on, lies in the start relay. This small element is responsible for supplying voltage to the compressor motor windings at the moment of start. If the relay is faulty, it tries to start the motor, a loud click is heard, but the start does not occur, and after a few seconds a second blow is heard.
This cycle can be repeated every few minutes until the refrigerator goes into protection mode or the thermal relay trips. Visually it looks like this: the motor hums for a couple of seconds, followed by a sharp click and silence. Over time, starting relay may completely fail, ceasing to close the circuit, or, conversely, stick, which is dangerous for the motor windings.
Replacing a relay is one of the simplest procedures in repairing refrigerators. However, before purchasing a new part, you need to make sure that it is the problem and not the compressor itself. Often the relay fails due to power surges or natural wear of the contact group inside the case.
For diagnostics, you can carefully remove the back cover (after unplugging the device from the outlet) and inspect the relay. If traces of soot, melting are visible on it, or the smell of burnt plastic is felt, the part requires replacement. It is important to choose an analogue with exactly the same characteristics indicated on the case.
Problems with the thermostat and sensors
A thermostat (thermostat) is a device that controls the temperature inside the chambers and gives a command to turn the compressor on or off. In mechanical models, this device is equipped with a contact group, which makes a characteristic click when opened or closed. If this sound becomes too loud, frequent, or is accompanied by unstable operation of the refrigerator, the thermostat may be faulty.
In modern electronically controlled models, the role of the thermostat is performed temperature sensors. They do not click on their own, but their incorrect readings can cause the controller to constantly turn the compressor or other components (such as fans or defrost valves) on and off. This creates the illusion of constant operation of the mechanisms.
If the thermostat is “stuck” in the “on” position, the refrigerator will work without stopping, which will lead to the formation of an ice coat and spoilage of food. If it does not close the contacts, the equipment simply will not start, although the light will be on. Diagnostics requires the use of a multimeter to check the conductivity of the contacts when the temperature of the sensitive element changes.
- 🔸 Frequent clicks and turning on of the motor every 5-10 minutes indicate incorrect sensor readings.
- 🔸 The absence of a shutdown click when the temperature reaches a low temperature indicates sticking of the contacts.
- 🔸 Clicks when turning the knob should be clear; if they are not there, the mechanism is broken.
⚠️ Attention: When replacing the thermostat, it is important to correctly install the capillary tube (sensitive element) in the seat. Loose contact with the evaporator wall will lead to incorrect operation of the entire system.
Mechanical reasons: fan and ice
In refrigerators with a system No Frost fans are responsible for circulating cold air. If excess ice has formed in the freezer, the fan blades may touch the ice crust. This causes a rhythmic knocking or crackling noise that is often confused with relay clicking. The sound may increase when the door is opened, when some models force the fan to turn on.
Another mechanical reason is the ingress of foreign objects. Small parts, pieces of food or ice can get caught in the fan rotation area or vibrating parts of the compressor. It is also worth checking whether the tubes of the refrigeration unit are touching each other or the walls of the housing. When the motor is running, vibration is transmitted to the tubes, and they begin to rhythmically tap on the metal.
To fix the problem, it is often enough to completely defrost the refrigerator. If after 24 hours without power the ice melts and the clicking stops, then the problem was a violation of the defrost cycles. If the sound remains, disassembly and inspection of the internal components will be required.
☑️ Diagnostics of mechanical noise
Table: Diagnostics by sound type and symptoms
To quickly determine the cause of the malfunction, compare the nature of the sound with the behavior of your refrigerator. Below is a table to help classify the problem.
| Sound type | Associated symptoms | Probable cause | Difficulty of repair |
|---|---|---|---|
| Loud click, then silence | The refrigerator does not freeze, the light is on | The starting relay or compressor is faulty | Average |
| Frequent crackling/clicking | The temperature in the chamber is constantly fluctuating | The thermostat or sensor is faulty | Low |
| Rhythmic knocking | The noise increases during operation | Fan touches ice or object | Low (defrost) |
| Quiet single click | Operation in normal mode | Normal operation of valves or thermostat | Not required |
By analyzing this data, you can understand whether you should call a technician right now or you can wait until the end of the defrosting cycle. Remember that compressor is the heart of the refrigerator, and if it tries to start, but cannot, its resource is quickly exhausted.
When you need to call a specialist
There are situations when self-repair not only will not help, but will also aggravate the situation. If, after replacing the start relay and thermostat, the refrigerator continues to click and does not turn on, the problem may lie in the motor-compressor itself. An interturn short circuit of the windings or a wedge of the piston group requires complex professional equipment for diagnosis and replacement.
Also, do not go inside the system if you hear hissing or smell chemicals. This may indicate a freon leak. In such cases an attempt at self-repair can lead to complete failure of the system and environmental contamination with refrigerant.
A master is needed if:
- 🛠 The compressor hums, clicks and gets very hot, but not starts.
- 🛠 Traces of oil are visible around the pipes or compressor.
- 🛠 The electronic control module makes a series of clicks and does not respond to buttons.
Why can’t you ignore relay clicks?
If the relay constantly clicks, Trying to start a faulty compressor, it may melt and close the contacts. In the worst case, this will lead to burning of the motor windings, the replacement of which costs up to 70% of the price of a new refrigerator.
Prevention and care of equipment
To reduce the risk of problems with starting equipment and mechanical components, it is important to ensure correct operating conditions. First of all, this is a stable voltage in the network. Electricity surges are the main enemy of electronics and motor windings.
It is recommended to use surge protectors or voltage stabilizers, especially in houses with old wiring. It is also important to keep the condenser (the grill at the back of the refrigerator) clean. Dust leads to overheating of the compressor, which causes it to work with overload and can cause safety shutdowns accompanied by clicking sounds.
Regular defrosting (even for No Frost systems, at least once a year) will help avoid ice build-up in hard-to-reach places and will extend the life of fans and defrost sensors. Following these simple rules will allow your equipment to work quietly and for a long time.
Why does the refrigerator click but does not freeze?
Rather In general, the compressor start relay or the compressor itself has failed. The relay tries to start the engine, a click is heard, but due to a malfunction the start does not occur. Diagnostics with a multimeter is required.
Is it normal that the refrigerator clicks during operation?
Yes, if the clicks are quiet, rare and are accompanied by normal cooling. This could be the operation of the thermostat, valves, or thermal expansion of the plastic. You should only worry if there are frequent loud clicks and no cold.
Is it possible to change the start relay yourself?
Yes, if you have basic skills and tools (screwdriver, pliers). The main thing is to buy a relay of exactly the same brand and model as the old one, and connect the contacts correctly according to the diagram on the case.
What to do if clicks appear after defrosting?
Perhaps there is ice left in the system, which interferes with the operation of the fan, or moisture has got on the contacts. Let the refrigerator stand turned off for a few more hours in a warm room, then wipe all accessible contacts dry.