The situation when a household refrigerator turns on and immediately turns off is one of the most common and alarming for the owner. This is usually accompanied by a characteristic click, a hum that ends abruptly, and the cycle repeats after a few minutes or seconds. This behavior of the equipment indicates that protective mechanisms or faulty components do not allow the engine to start normally.
Ignoring the problem can lead to failure compressor, which is the most expensive component of the unit. In some cases, the reason lies in a banal power surge or a burnt out light bulb, but most often the electrical part of the engine is to blame. It is important not to try to turn on the device endlessly, so as not to aggravate the breakdown.
In this article we will analyze the main reasons why The refrigerator clicks on and offand consider diagnostic methods available at home. You will learn how to check the start relay, thermostat and motor windings, and also understand when you need to call a technician.
Diagnostics of the compressor and start relay
The most common reason for cyclic on and off lies in the engine starting system. The compressor is the heart of the refrigerator, and to start it requires a powerful impulse, which is provided by the start relay. If this unit is faulty, the engine tries to start, hums for a few seconds, then a click is heard and the power is turned off.
Often the problem is a burnt out winding or sticking contacts inside the relay itself. Older models with asynchronous motors used starter protection devices that lost their properties over time. Modern inverter systems are more complex, but the principle of overload protection remains similar.
For an initial check, you need to turn off the power to the unit, remove the back panel and get to the compressor. Carefully remove the plastic cover from the start relay. If inside you see traces of burning, melted plastic or smell burning, then starting relay requires replacement. This is a consumable item that can be easily found in spare parts stores for the model of your refrigerator.
⚠️ Attention: Before any manipulations with electrical components, be sure to disconnect the refrigerator from the mains. Residual voltage in capacitors can be dangerous.
If there are no visual defects, the relay can be checked by shaking it next to your ear. The sound of an object dangling inside (like coins in a glass) indicates that the internal mechanical part is destroyed. In this case, starting the motor is impossible without replacing the part.
Faults of the thermostat and temperature sensors
The second most common culprit is which the refrigerator turns off after a few secondsis a thermostat. This component is responsible for maintaining the specified temperature. If its contacts are stuck in the “open” position or the sensor transmits incorrect data to the electronic module, the motor will not receive a command to operate.
In mechanical refrigerators, the thermostat is a device with a bellows filled with refrigerant. As temperature changes, the bellows expands or contracts, opening or closing contacts. Over time, the gas may evaporate, or the membrane may lose elasticity, which will lead to incorrect operation.
Electronic control systems use temperature sensors (thermistors), the resistance of which changes depending on the heat. If the sensor “lies” and shows the module that the chamber is already colder than it actually is, the compressor may not turn on at all or work with long interruptions. However, if the sensor shows critical overheating, the protection system may block the start.
- 🔹 Check whether the temperature settings on the display or controller are correct.
- 🔹 Listen to whether there is a click when turning the thermostat knob to the extreme positions.
- 🔹 Pay attention to the condition of the capillary tube thermostat - it should not be damaged.
Diagnostics of the thermostat often requires testing the contacts with a multimeter. In normal condition, at room temperature, the contacts should ring. If the device shows a break, the part must be changed.
Problems with inter-turn short circuit of the motor windings
The most serious and expensive problem, due to which the refrigerator hums and turns off is an inter-turn short circuit in the compressor windings. This occurs when the insulation between the turns of copper wire inside the motor is broken, which leads to a short circuit and a sharp increase in current.
A protective relay (thermal) instantly reacts to a surge in current and breaks the circuit to prevent fire or permanent breakdown of the motor. After cooling, the relay closes the circuit again, and the cycle repeats. A characteristic sign of such a malfunction is a very loud, strained hum and rapid, strong heating of the compressor housing.
You can check for a short circuit using a multimeter by measuring the resistance between the contacts on the compressor terminal block. Normal resistance values for different pairs of contacts (starting, operating, common) are usually from 10 to 60 ohms. If the device shows zero or a value very close to zero, there is a short circuit.
Is it possible to start a refrigerator with an interturn circuit?
Theoretically, some craftsmen use special devices for starting “through a finger,” forcibly supplying current. However, this is a temporary measure for a few days or weeks, after which the compressor will burn out completely. The operation of such a refrigerator is fire hazardous.
If an interturn short circuit is confirmed, repairs, as a rule, involve a complete replacement of the compressor. Rewinding windings in the factory for household models is not economically feasible and technically difficult.
The influence of voltage surges and wiring
Unstable voltage in the electrical network is a frequent external factor that causes malfunctions of refrigeration equipment. If the voltage drops below the permissible minimum (usually 190-200 Volts), the motor starting current is insufficient to overcome the resistance in the system. The motor hums, but does not start, and the thermal relay turns it off.
The opposite situation - a sharp voltage surge - is also dangerous. The electronic control module may go into protection mode or be damaged. In modern models with inverter compressors sensitivity to the quality of electricity is much higher.
It is also worth checking the condition of the socket and plug. Oxidized contacts, a loose plug, or an old, “loose” socket can create high contact resistance. This leads to a drop in voltage at the input to the refrigerator and heating of the wiring, which is perceived by the system as a malfunction.
⚠️ Attention: The use of cheap Chinese extension cords and low-quality surge protectors often becomes the reason that a powerful compressor does not receive sufficient power to start.
To protect equipment, it is recommended to use voltage stabilizers, especially in private homes or areas wiring. This will extend the life of not only the refrigerator, but also other household appliances.
Comparative table of symptoms and causes
To simplify the initial diagnosis, we have compiled a table that will help compare the observed symptoms with the most likely causes. Remember that an accurate diagnosis can only be made by a specialist with the appropriate equipment.
| Symptom | Probable cause | Difficulty of repair | Necessary actions |
|---|---|---|---|
| Buzzing for 5-10 seconds, click, pause | Faulty start relay | Low | Replacement of relay |
| Strong hum, case heating, shutdown | Interturn short circuit | High | Replacing the compressor |
| The refrigerator is silent, there is no light | Thermostat or wiring is burnt out | Average | Chain continuity, thermostat replacement |
| Short switching on, no cold | Freon leakage | High | Search for leaks, refill |
| Chaotic on/off | Problems with the electronic module | High | Board diagnostics, re-soldering |
As can be seen from the table, some faults can be fixed independently with minimal skills, while others require the intervention of professionals. For example, replacing the start relay takes 15 minutes, and replacing the compressor requires evacuation of the system and charging with refrigerant.
Refrigerant leak and clogged capillary
Although freon leak More often it manifests itself in the fact that the refrigerator simply stops freezing; in some cases, it can lead to strange behavior of the motor. If the refrigerant in the system is critically low, the suction pressure drops, the compressor runs “idle” and may overheat, triggering the thermal protection.
An even more likely cause in the hydraulic part is a clogged capillary tube (clogging). Oil breakdown products or moisture that gets into the system can crystallize and block the freon flow. The discharge pressure rises sharply, the compressor cannot push through the plug, overheats and turns off.
Signs of a clogged capillary are often:
- 🔹 The compressor is hot, and the condenser (grid at the back) is cold or only partially warm.
- 🔹 A characteristic whistle or hiss when trying to start.
There is only one treatment in this case: complete refilling of the system with nitrogen purging and replacement of the filter-drier. It is impossible to carry out this procedure independently without special equipment (vacuum pump, pressure gauge station, scales).
When it is necessary to call a technician
There is a clear line between DIY repairs and the need for professional intervention. If you have checked the socket, the voltage in the network, replaced the start relay and thermostat, and the refrigerator continues to click and turn off, further self-diagnosis may be useless or dangerous.
A technician is needed if required:
- 🔹 Opening a sealed circuit (replacing the compressor, eliminating leaks, cleaning the capillary).
- 🔹 Repairing or replacing the electronic control module (requires soldering and knowledge of circuitry).
- 🔹 Replacing the compressor itself (requires skills in working with tools and refrigerants).
In addition, if your refrigerator is under warranty, any independent repairs associated with broken seals will lead to loss of warranty. In such cases, the only correct solution is to contact an authorized service center.
⚠️ Attention: Refrigerants used in modern refrigerators may be flammable or under high pressure. Incorrect actions when working with tubes can lead to an explosion or fire.
A timely call to a specialist often saves money, since a faulty compressor running on wear and tear burns out much faster than a serviceable one, but operating in abnormal mode.
☑️ Checklist before calling a specialist
Prevention and operating rules
To avoid the situation when the refrigerator turns on and immediately turns off, it is important to follow the operating rules. First of all, this concerns defrosting. In No Frost systems, the evaporator is hidden, but in drip systems, the formation of an ice coat more than 5-7 mm thick significantly increases the load on the compressor.
It is also not recommended to install the refrigerator close to the wall or in a niche without gaps for ventilation. The condenser must efficiently transfer heat to the environment. If damaged, the pressure in the system increases, and the motor can go into protection.
Regular cleaning of the rear wall from dust and cobwebs also prolongs the life of the equipment. The dust layer acts as a heat insulator, interfering with the cooling of the compressor and condenser. Wipe the radiator grill with a dry cloth or vacuum it every six months.
Following these simple rules will help avoid premature wear of parts and ensure stable operation of your refrigerator for many years. Remember that prevention is always cheaper than major repairs.
How long should the refrigerator operate after switching on?
Normally, the compressor operating cycle ranges from 20 to 40 minutes, followed by a pause of 15-30 minutes. If the cycle is shorter than 5 minutes or longer than an hour, this is a reason for diagnosis.
Why does the refrigerator hum but does not start, although the relay is new?
If you replaced the start relay and the situation has not changed, the problem may be in the compressor itself (jamming of the piston group or interturn short circuit) or in the absence of voltage at the input to the relay due to a malfunction wiring or control module. It is also possible that the new relay is defective or does not match the characteristics of your motor model.
Is it possible to temporarily use a refrigerator if it often turns off?
Using equipment in this mode is extremely undesirable. Frequent starts and stops (clocking) lead to overheating of the windings and rapid failure of the compressor. In addition, food may spoil due to temperature violations. It is better to turn off the device until the malfunction is eliminated.
How much does it cost to replace the start relay in the service?
The cost consists of the price of the part itself (usually from 500 to 1500 rubles depending on the model) and the cost of the technician’s work. On average, calling a technician to replace the relay will cost 2000-3500 rubles, which is much cheaper than replacing the compressor.
Does a full refrigerator load affect the start of the compressor?
A full load of food in itself does not affect the electric start of the motor. However, if food blocks the ventilation openings (in No Frost systems) or is placed close to the back wall, this interferes with air circulation. The compressor will work longer to cool the volume, which can lead to overheating and subsequent shutdown due to thermal protection.