The situation when No Frost refrigerator makes loud clicks, but the unit itself does not start or works intermittently, often takes the owner by surprise. These sounds can be single, repeated at regular intervals, or chaotic, which immediately causes anxiety. In most cases, such manifestations indicate attempts by the compressor electric motor to start, but encounter a technical obstacle.
Understanding the nature of the sound is critical for further actions, since ignoring the problem can lead to complete failure of an expensive unit. Click - this is usually the sound of an opening or shorting of electrical contacts inside the start relay or thermostat. If you hear a series of clicks followed by a hum, but the compressor does not start, it means that the starting winding is receiving power, but the rotor cannot budge.
Modern systems No Frost are more complex than classic drip models, so there are more sources of extraneous sounds here. This could be either a simple network overload or a failure of the defrost sensors. It is important not to panic, but to consistently analyze the nature of the sound and the accompanying symptoms in order to make the right decision about the need to call a technician.
⚠️ Attention: If clicks are accompanied by a burning smell, smoke or sparking, immediately disconnect the device from the power supply. Further operation in this state is a fire hazard.
The principle of operation of the starting relay and its effect on starting
The main "culprit" of characteristic clicks in 80% of cases is starting relay. This small electromechanical unit is responsible for supplying voltage to the starting winding of the compressor at the moment of start. As soon as the motor rotor reaches the required speed, the relay must turn off the starting winding so that the motor continues to operate on the main one. If this mechanism is worn out or dirty, the contacts begin to “spark” and click, trying to close the circuit.
In systems No Frost the relay is often combined with a thermal protective device. When attempting to start, the compressor consumes maximum current. If the rotor is jammed or the winding is overheated, the current increases, the thermal protection is triggered and opens the circuit - a click is heard. Then the protection cools down, closes the circuit again, and the cycle repeats. This phenomenon is called "cyclic starting", and it is extremely harmful to the motor windings.
Relay diagnostics require caution. Sometimes it is enough to remove the cover, carefully remove the relay and shake it near your ear. If you hear the sound of broken glass inside or the rolling of parts, it means that the starter is physically destroyed. In some models, for example Indesit or Atlant, relays may fail due to power surges in the network.
How to test a relay with a multimeter
To check, you need to ring the relay contacts in different positions. In the normal state, the resistance should be zero when the contacts are closed and infinite when they are open. If the device shows a “break” where there should be a circuit, or a “short circuit” everywhere, the part is faulty.
Compressor malfunctions: when a knock indicates a motor breakdown
If checking the relay did not produce results, but refrigerator continues to click and does not freeze, the problem may lie in the very heart of the unit - the compressor. The internal mechanism is a sealed unit where the piston group moves in oil. Over time, mechanical wear, lack of lubrication or moisture entering the circuit can lead to jamming of the pistons.
When the compressor tries to start, but the piston is jammed, a powerful starting current occurs. Thermal relay the protection detects the overload and emergency opens the contacts - you hear a click. After some time, the bimetallic plate cools down and supplies current again. The cycle is repeated until the winding burns out or the protection relay itself fails.
There is also the concept of “hydraulic hammer” when liquid refrigerant enters the compression chamber of the compressor. This often happens when the system is incorrectly charged or the defrost cycle is disrupted. In this case, the clicks may be more dull, and the start-up itself may be accompanied by strong vibration of the housing. No Frost. In this case, the clicks may be more dull, and the startup itself may be accompanied by strong vibration of the case.
The role of the thermostat and sensors in the No Frost system
Unlike older models, refrigerators with the system No Frost are equipped with complex control electronics. Not only the mechanical thermostat, but also electronic sensors (thermistors) are responsible for the temperature regime. If the thermostat is “stuck” in the “Off” position or its contacts have oxidized, it may make clicking sounds, opening and closing the circuit chaotically.
Particular attention should be paid to the evaporator defrost sensor. In No Frost mode, the ice on the evaporator should melt regularly. If the sensor incorrectly reads the temperature, it can command the compressor to turn on when it is not needed, or, conversely, block the start. The electronic control module, receiving conflicting signals, may try to start the system, which is accompanied by characteristic clicks of the relay on the board.
Often owners confuse the clicks of the thermostat with the operation of other components. The mechanical thermostat makes a loud, ringing click when the set temperature is reached. This is fine. But if the clicks are frequent and the temperature in the chambers does not drop, it means that the contact is broken or the calibration has gone wrong.
Problems with electrical wiring and mains voltage
Unstable voltage in the household network is the hidden enemy of household appliances. If the voltage drops below the permissible threshold (usually 190-200 Volts), electric motor it cannot develop the necessary power to start. The starting relay is triggered and tries to start the motor, but due to lack of energy the rotor does not spin. A reset occurs and a second attempt occurs - the cycle of clicks continues.
It is also worth checking the condition of the socket and plug of the power cord. Loose contacts in an outlet may spark and produce cracking or clicking noises that are mistakenly attributed to the inside of the refrigerator. Oxidation of the contacts at the junction of the cord with the body of the unit also leads to heating and characteristic sounds.
To diagnose this problem, you can connect the refrigerator to another outlet, preferably in another room, using an extension cord with known good contacts. If the nature of the sounds has changed or the clicks have disappeared, the problem lies in the home electrical wiring, and not in the equipment.
⚠️ Attention: Using cheap Chinese extension cords or low-quality surge protectors can aggravate the problem with starting the compressor due to high contact resistance.
Fault diagnosis: step by step algorithm
Before calling a technician, you can conduct an initial diagnosis to narrow down your search. This will help the specialist quickly determine the cause over the phone and bring the necessary spare parts. The main rule is safety: carry out all manipulations inside the case only with the device disconnected from the network.
First of all, listen to where exactly the sound is coming from. If it clicks at the back, below, where the compressor is located, it is the relay or the motor itself. If the sound is heard inside the refrigerator compartment or near the control panel, most likely the problem is in the thermostat or electronic module.
Check the operation of the refrigerator in different modes. Try turning the thermostat knob to minimum and maximum. If the clicks become more frequent or change tone when you turn the knob, it means that the mechanics of the thermostat are working properly, but perhaps do not keep the contact in the working position.
☑️ Primary diagnostics of the refrigerator
Comparative table of symptoms and causes
For the convenience of systematizing the data obtained, it is recommended to compare the symptoms of your situation with typical signs of malfunctions. This will help distinguish a starter problem from a compressor breakdown.
| Symptom | Probable cause | Sound character | Difficulty of repair |
|---|---|---|---|
| Single click, silence | Faulty starting relay | Sounding, metallic | Low (relay replacement) |
| Series of clicks, humming | Stuck compressor | Thud knocking, humming | High (motor replacement) |
| Clicks inside the chamber | Thermostat is faulty | Sharp crackling | Medium (sensor replacement) |
| Cracking clicks in the network | Bad contact in the socket | Sparking crackling | Low (replacement sockets) |
When you need to call a professional technician
There are a number of situations when self-repair is not only impractical, but also dangerous. If, after replacing the starting relay (the most common and simplest operation), refrigerator continues to behave the same, then the problem is deeper. Most likely, a compressor replacement or complex diagnostics of the electronic control board is required.
In systems No Frost there is often an open circuit of the defrost heating element or a malfunction of the timer. Without specialized equipment (tester, pressure gauge station), it is extremely difficult to diagnose these components. The technician will be able to determine exactly why the defrost cycle does not start, which indirectly affects the compressor load.
Also, the help of a specialist is necessary if evacuation of the system and charging with refrigerant is required. Independent intervention in a sealed circuit without a pump and scales will lead to rapid damage to the new compressor. Modern freons require precise dosage; an error of 10-20 grams can disrupt the operation of the entire system.
⚠️ Attention: By opening the sealed circuit yourself, you lose the warranty on the device (if it is still valid) and risk getting poisoned by refrigerant vapors or burns if oil gets on your skin.
Prevention and extension of service life
To avoid situations when the refrigerator clicks and stops freezing, it is important to follow the operating rules. Regular defrosting (even for No Frost systems, complete defrosting is recommended once a year) helps avoid the formation of ice jams, which increase the load on the motor.
Ensure adequate ventilation of the rear wall. The compressor should not overheat, since overheating often leads to the thermal protection triggering and subsequent clicking noises. The distance from the wall to the rear grille should be at least 5-7 cm.
Use a voltage stabilizer if the light often “jumps” in your area. Sudden voltage drops are the main cause of failure of the starting winding and relay. A high-quality stabilizer will work as a buffer, smoothing out current peaks and drops.
Is it possible to temporarily operate the refrigerator if it clicks?
Short-term operation is possible only if the clicks are rare and the refrigerator continues to freeze. If the clicks are frequent, but there is no cold, operation will lead to the combustion of the compressor windings in a few hours. In this case, the device needs to be turned off.
How much does it cost to replace the starting relay?
The relay itself is inexpensive (from 500 to 1500 rubles depending on the model), but the work of a diagnostic and replacement technician can cost from 1000 to 2500 rubles. The exact price depends on the region and the difficulty of accessing the unit.
Why does the refrigerator click after defrosting?
If clicks appear after defrosting, water may have gotten into the electrical contacts or into the start relay. It is necessary to allow the appliance to dry completely for 24 hours when turned off before turning it on again.
Does the installation level affect clicks?
Yes, if the refrigerator is not level, the compressor may operate with increased vibration, which leads to displacement of internal parts and rubbing elements. This can cause a mechanical knock, which can be confused with an electrical click.