The situation when the refrigerator turns on, makes a characteristic hum, and then after a few seconds a click is heard and the unit goes silent is a classic sign of a technical malfunction. This behavior of the equipment indicates that motor-compressor it is trying to start, but the protective automation forcibly breaks the power circuit. This occurs to prevent burnout of the motor windings or failure of other expensive components. At this moment, the owner can observe how the indicator lights up and goes out, or simply hear periodic clicks at intervals of 2-3 minutes.
It is absolutely impossible to ignore such a symptom, since constant attempts to start create a colossal load on the electrical network of the apartment and the equipment itself. If you notice that your Indesit, Atlant or Beko behaves in this way, you must immediately disconnect the device from the network and carry out initial diagnostics. In most cases, the problem lies in one of three elements: the starting relay, the compressor itself, or the thermoregulation system.
Timely identification of the cause will avoid more complex and expensive repairs that may be required during long-term operation of a faulty unit in emergency mode. Below we will analyze in detail the main factors leading to this behavior and methods for eliminating them.
Failures of the starting relay and protective thermal contact
The most common reason why the refrigerator clicks and turns off is the failure of the starting relay. This small unit is responsible for supplying voltage to the starting winding of the compressor at the moment of start. Inside the relay body there is a coil and a movable core, which, when heated by current, closes the contacts. Over time, the plastic of the case is deformed from heating, and the contacts burn, which leads to sticking or, conversely, the impossibility of closing the circuit.
If the relay is faulty, the compressor receives power and begins to hum, but the rotor cannot budge due to the lack of impulse to the starting winding. The current in the circuit increases sharply, which causes heating of the bimetallic plate protective thermal contact. The plate bends and opens the circuit, making that same click. After cooling (usually 2–5 minutes), the contact closes again and the cycle repeats. Visually, traces of burning or melting may be visible on the relay.
For diagnostics it is necessary:
- ⚡ Carefully remove the back cover of the refrigerator in the compressor area.
- 🔌 Disconnect the wires and remove the starting relay from the motor contacts.
- 👀 Inspect the insides for blackening, burning smell and mobility of the core.
⚠️ Attention: Before removing the relay, be sure to wait until the compressor has completely cooled down and disconnect the refrigerator from the network. Residual voltage may remain inside the relay, and hot contacts may cause burns.
Replacing the relay is a simple procedure that does not require any special tools other than a screwdriver. However, it is important to choose a model that is completely identical to the original, since the response parameters may differ from different manufacturers. An incorrectly selected relay will lead to rapid failure of a new compressor.
Problems with inter-turn short circuit of the compressor
If replacing the start relay did not bring results, and the refrigerator still turns on and immediately turns off, the problem may lie in the very heart of the unit - motor-compressor. The most likely diagnosis in this case is an interturn short circuit in the motor windings. This is a serious malfunction in which the insulation of the copper wire is broken, and the current begins to flow along a short path, bypassing part of the turns.
During an interturn short circuit, the winding resistance drops, which leads to a sharp jump in current consumption. The protective relay, reacting to an overload, instantly turns off the power to prevent fire. A characteristic sign of such a breakdown is a specific smell of burning or scorched wiring, which may appear in the compressor area after several cycles of switching on. Also, the motor housing can heat up to very high temperatures much faster than usual.
You can diagnose a short circuit using a multimeter by measuring the resistance of the windings. Normal values usually vary within:
- 📉 Starting winding: from 20 to 40 Ohms (depending on the model).
- 📈 Operating winding: from 10 to 25 Ohms.
- 🔌 Common contact: sum of resistances starting and operating windings.
If the device shows a resistance close to zero or, conversely, infinity (break), the compressor must be replaced. Repairing windings at home is neither possible nor economically feasible. In addition, when a faulty motor is operating, there may be metal shavings in the oil, which, if they enter the cooling system, will clog the capillary tube.
Is it possible to revive a compressor with a short circuit?
There are traditional methods of “treating” compressors by applying high voltage with short-term pulses, but this is only a temporary measure. The service life of such a motor is calculated in days, and the risk of fire increases many times over. Professional craftsmen do not recommend using such methods in domestic conditions.
Compressor jamming and mechanical damage
Another reason why the refrigerator turns on for a few seconds and turns off is mechanical jamming of the compressor piston group. This condition is often called a "wedge". The motor tries to turn the shaft, but due to lack of lubrication, scoring on the cylinders or foreign objects, the piston gets stuck at a dead center. The hum in this case is very loud, intense, turning into a hum, followed by a click of protection.
A wedge can occur for several reasons:
- Depletion of service life and wear of rubbing parts.
- Operation in overheating mode (insufficient rear ventilation).
- Attempt to start immediately after shutdown (the 10-minute rule was not followed).
There is a “wedging” method, which sometimes helps to revive the unit. Its essence is to supply voltage directly to the working winding, bypassing the starting relay, which creates a powerful starting torque. However, this method is dangerous and requires electrical skills. If after 3-5 attempts the compressor does not start, further experiments may lead to the final rotation of the liners and destruction of the mechanism.
| Symptom | Probable cause | Sound character | Solution |
|---|---|---|---|
| Quiet hum, click after 5-10 seconds | Faulty start relay | Single click | Replacing the relay |
| Strong hum, heating of the case | Interturn closure | Humming + clicking | Replacing the compressor |
| Strained roar, vibration | Compressor wedge | Smooth powerful hum | Attempt to wedge or replace |
| Clicks without hum | Thermostat is faulty | Frequent clicks | Replacing the thermostat |
Malfunction of the thermostat and sensors
In some models of refrigerators, especially old ones or, conversely, equipped with complex electronics, the problem may lie in the control system. If thermostat (the thermostat) is faulty, it may give false signals to turn on and off. However, in the case of cyclic switching on and off with an interval of several seconds, it is often not the temperature sensor itself that is to blame, but a short circuit in its circuit or the defrost sensor circuit.
The electronic control module, receiving erroneous data (erroneous data) about the temperature, can block the start of the compressor or initiate its emergency shutdown. In modern models LG, Samsung or Bosch an error code often lights up on the display. For example, an error in the evaporator sensor may result in the system not giving a command to start cooling, but at the same time trying to check the functionality of the system, turning on the compressor for a split second.
To check the thermostat in mechanical refrigerators, you can close its contacts directly. If after this procedure the refrigerator operates in normal mode (stops turning off), it means that the temperature sensor is faulty and requires replacement.
The influence of power surges and wiring
External factors cannot be ignored. If your apartment has unstable mains voltage, the compressor may not start due to lack of power. At low voltage (below 190 Volt), the starting torque of the engine is not enough to turn the piston, and the thermal protection is triggered. This often happens in the evening in holiday villages or areas with old wiring.
The problem may also lie in the socket or extension cord. Oxidized contacts, loose twisting of wires, or the use of cheap tees lead to a voltage drop exactly at the point where the refrigerator is connected. As a result, the motor receives insufficient current, hums and turns off. This is easy to check: plug the refrigerator directly into another, known-to-work outlet, preferably in the kitchen or in the hallway, bypassing all adapters.
It is recommended to install a separate voltage relay or stabilizer on the refrigerator. This device will protect equipment not only from low voltage, but also from dangerous surges that can break through the compressor winding in a split second. Modern voltage relays have an on-delay setting, which is also useful for the compressor.
⚠️ Attention: Using conventional surge protectors (pilots) for refrigerators is often ineffective. They protect only from short-term interference, but do not stabilize the voltage and do not provide the necessary restart delay.
Diagnostics and action algorithm
If you encounter the problem described, do not panic and act consistently. Chaotic disassembly of components can lead to damage to copper tubes or electrical parts. First, rule out the simplest causes, such as problems with the socket or overheating.
Testing algorithm:
- 🔍 Unplug the refrigerator for 15-20 minutes to cool the thermal contact.
- 🔌 Check the voltage in the socket with a multimeter or connect another powerful one device.
- 👂 Listen: is the compressor humming before clicking or is there silence.
- 🛠 Inspect the starting relay for external defects.
☑️ Primary diagnostic checklist
If simple methods do not help, more in-depth diagnostics will be required, including checking the windings and replacing components. If you do not have the skills to work with electrical appliances, it is better to contact a specialist. Repairing a compressor group requires not only electrical knowledge, but also skills in working with the refrigeration circuit (vacuuming, refilling with freon), if the motor needs to be replaced.
FAQ: Frequently Asked Questions
Can a refrigerator turn on and off due to a lack of freon?
Itself The lack of freon does not cause frequent switching on and off with clicks. If there is a refrigerant leak, the compressor will work almost continuously, trying to gain temperature, or it will turn on rarely, but work for a long time. However, if the system has a pressure or discharge temperature sensor, its readings may block starting, but this is a rarer scenario for household models.
How much does it cost to replace the starting relay?
The cost of the relay itself is low and usually ranges from 300 to 1000 rubles, depending on the brand and model. The replacement services will cost more, as they include diagnostics and travel. Replacing it yourself saves the budget, but requires caution.
Is it dangerous to continue to operate a refrigerator that is clicking?
Operation in this mode is dangerous. Constant inrush currents can cause the wiring to catch fire, the socket to melt, or the compressor to completely burn out. In addition, the food in the chamber will begin to deteriorate due to lack of cooling. It is recommended to stop using until the problem is resolved.
Why does the refrigerator hum but does not start after defrosting?
If you have just defrosted the refrigerator (No Frost or drip) and turned it on, let it stand turned off for at least 2-3 hours. Freon may have dissolved in the compressor oil, and it takes time to separate it. An early start can lead to water hammer and a wedge.