The situation when the refrigerator suddenly stops humming, and after a few hours you find puddles of water and defrosted food inside, can shock any owner. Usually this process is accompanied by a frightening silence, followed by a sharp start of the unit, which immediately calms down again. Understanding why the refrigerator turns off and defrosts itselfis the key to maintaining a supply of food and preventing expensive repairs.
In most cases, such cyclical operation is not a breakdown in the usual sense, but a failure in the control system or protective reaction. Modern models Indesit, Atlant or Beko are equipped with complex electronics that can erroneously interpret data from sensors. If you notice that the equipment turns on for a couple of minutes and turns off, or works for too long and then remains silent for a long time, you need to conduct an initial diagnosis.
Independent search for the cause requires attentiveness and compliance with safety precautions. Often the problem lies in a simple overheating or power surge, but it can also indicate a serious freon leak. Below we will analyze in detail the main scenarios of the unit's behavior.
Cyclic operation and No Frost system
If your refrigerator is equipped with a system No Frost, then periodic stopping and starting is the normal operating mode, but with reservations. In such models, automatic defrosting of the evaporator occurs several times a day. At this moment, the compressor may turn off, and the heating element, on the contrary, may turn on. However, if the cycles become too frequent or long, the system has failed.
The main control element here is a timer or an electronic module. If the timer is stuck in the defrost position, the compressor will not start until the time has expired or the emergency thermostat has tripped. As a result, the chamber heats up and the food begins to spoil. Users often confuse normal operation with a malfunction when they hear clicks and noise of flowing water.
- ⚡ Defrost timer: a mechanical device that switches between cooling and defrosting modes. If it is broken, the cycle is lost.
- 🌡️ Thermostat: sensor that controls the temperature. If it malfunctions, the compressor may not receive a signal to start.
- ❄️ Evaporator: When ice overgrown, heat exchange is disrupted and the sensors may give incorrect readings.
It is important to distinguish between the normal cycle and emergency mode. If the refrigerator turns off by itself and defrosts, but it remains cold inside, the settings may simply have gone wrong or there has been a power surge. If the temperature rises to room temperature, intervention is required.
⚠️ Attention: Do not try to forcefully defrost a refrigerator with a No Frost system more than once a year. Frequent defrosting can damage the plastic elements and disrupt the operation of the air dampers.
Problems with the compressor and start relay
The most alarming situation is when the refrigerator turns on, buzzes for 5-10 seconds, then there is a click and it turns off. This is a classic symptom thermal relay or problems with the compressor itself. The motor tries to start, draws a high starting current, the windings heat up, and the protection cuts off the power to prevent a fire or permanent breakdown of the motor.
Often the culprit is the starting relay. This is a small part that provides an impulse to start the engine. If the contacts inside the relay are burnt or the mechanism is jammed, the compressor will not be able to reach operating mode. Replacing this part is usually inexpensive and quick, but requires accurate diagnosis.
A more serious case is interturn short circuit in the compressor windings or its mechanical wedge. In this case, the engine hums and vibrates, but cannot start. It is impossible to operate the equipment in this mode: each start brings the compressor closer to final death, and can also damage the wiring in the house.
Malfunctions of the thermostat and temperature sensors
The thermostat is the “brain” that decides when to turn on the cold. If this element fails, it may send false signals. For example, the thermostat “thinks” that the chamber is already cold enough and turns off the compressor, although it is warm inside. Or vice versa - it does not allow it to start, considering that the temperature has not yet reached the switching threshold.
In models with electronic control (LG, Samsung, Bosch) instead of a mechanical thermostat, air sensors are used. They can oxidize, break, or produce incorrect data due to condensation. The electronic module, receiving a signal that “everything is fine,” turns off the cooling system. Visually, this looks like spontaneous defrosting.
To check a mechanical thermostat, the “short circuit” method is often used. If, when connecting the contacts, the compressor starts and operates normally, then the problem is in the sensor. However, this number will not work with electronics - it requires a multimeter and resistance measurements.
- 🔧 Mechanical thermostat: checked by checking the contacts in a warm and cold state.
- 📡 Electronic sensor: requires measuring resistance at a certain temperature.
- 🔌 Contacts: often oxidize, which leads to signal loss.
⚠️ Attention: When replacing a thermostat, it is important to use a part with the same markings. Installing an inappropriate sensor will lead to incorrect operation of the refrigerator: either it will freeze too much or will not turn on at all.
Protection against power surges and overheating
Unstable voltage in the network is the scourge of many areas. If the voltage drops below the permissible threshold or, conversely, there is a sharp jump, the built-in compressor protection may be triggered. Some modern models have built-in stabilizers or voltage control relays that turn off the power in the event of anomalies in the network.
It is also worth considering the problem overheating. If the refrigerator is located close to the wall, the radiator on the rear wall is not blown by air. The compressor heats up, the thermal relay trips and the unit turns off. After it cools down it tries to start again. This cycle can be repeated endlessly until you move the equipment.
Check the condition of the wiring and socket. Poor contact in a plug or socket causes heating and voltage drop, which is perceived by equipment as an emergency situation. In such cases, the refrigerator turns itself off, saving the electronics from burning out.
Diagnosis table of main symptoms
To make it easier for you to navigate the nature of the malfunction, we have compiled a summary table. It will help compare symptoms with the most likely causes. Remember that only a technician with professional equipment can make an accurate diagnosis.
| Symptom | Probable cause | Difficulty of repair | Need for a technician |
|---|---|---|---|
| Buzzing 5-10 seconds, click, silence | Start relay or compressor wedge | Medium/High | Desirable |
| Works for a long time, then is silent for a long time, the chamber is warm | Thermostat or sensor is faulty | Low | Possibly by yourself |
| Cycically turns on/off, no ice on the walls | Freon leak or capillary clogged | High | Required |
| Turns off when the light or other equipment is turned on | Power surges | Low (stabilizer needed) | No |
As can be seen from the table, some problems can be solved by simply replacing the sensor, others require calling a specialist to fill with freon or replace the compressor. You should not ignore the symptoms, as prolonged operation in emergency mode can damage adjacent components.
Refrigerant leakage and system blockages
One of the hidden reasons why the refrigerator turns on and off is freon leak. When there is not enough gas in the system, the compressor works hard, trying to gain temperature. Sensors detect that the cold is not setting in and can forcibly turn off the unit for protection, or the operation cycle is disrupted due to changes in pressure.
Clogged capillary tube is another technical problem. Ice blockage or debris is blocking the refrigerant flow. The pressure at the compressor outlet increases, the protection is triggered, and it stalls. After cooling, the plug may dissolve, the pressure will equalize, and the refrigerator will work again for a short time.
It is difficult to diagnose a leak or blockage at home. Often the only sign is that the condenser (grid at the back) is only partially hot or, conversely, cold when the compressor is running. Oil may also appear under the refrigerator.
Failures in the electronic control module
In modern refrigerators, everything is controlled by the “brain” - an electronic board. Voltage surges, moisture ingress, or simply a manufacturing defect can lead to malfunctions in its operation. The module can randomly issue commands to turn on and off the compressor, fan and heating element.
Often such failures are accompanied by blinking indicators on the control panel or the appearance of error codes. For example, flashing light bulbs may indicate problems with sensors, and blinking light bulbs may indicate an inverter malfunction. A reboot (unplug for 15 minutes) sometimes helps clear the error, but if the defect is physical, the problem will return. Indesit flashing lights may indicate problems with the sensors, and LG - inverter malfunction. A reboot (unplug for 15 minutes) sometimes helps clear the error, but if the defect is physical, the problem will return.
Repairing the module requires soldering and deep knowledge of electronics. Most often, the board is changed entirely or reflashed. If you notice that the refrigerator behaves “illogically” (for example, it freezes to -30 or does not turn on when there is obvious heat inside), most likely the problem is in the electronics.
⚠️ Attention: Before replacing or repairing the electronic module, be sure to make sure that all sensors are in working order. The control board is often declared “to blame,” although the problem was in a cheap sensor that gave the wrong signal.
When you need an urgent call to a technician
There are situations when independent experiments can lead to a fire or permanent breakdown of equipment. If you smell a burning smell, see sparking, or feel electric shock from the chassis, immediately unplug the power cord. A technician is also needed if the refrigerant circuit needs to be opened.
Do not delay repairs if the refrigerator has stopped freezing completely. Thawed food is a risk of poisoning, and an attempt to get the equipment to work can lead to combustion of the compressor, the cost of which is up to 70% of the price of a new refrigerator.
Professional diagnostics include checking the pressure in the system, the tightness of the circuit, and the serviceability of electrical circuits under load. This is the only way to accurately say why the refrigerator turns itself off and defrosts in your particular case.
Why does the refrigerator turn on for 1 minute and turn off?
Most likely, the thermal protection of the compressor is triggered due to a faulty starting relay or wedge in the motor itself. Less often, there is a problem in the wiring.
Is it possible to use a refrigerator if it is constantly defrosting?
It is highly not recommended. The food will spoil, and the constant on-off cycles will finish off the compressor. It is better to turn it off and call a technician.
How much does it cost to replace a thermostat?
The cost consists of the price of the part (usually inexpensive) and the work of the technician. On average, repairs cost 15-25% of the cost of a new refrigerator, which is economically feasible.
Does the temperature in the room affect the operation of the refrigerator?
Yes, if the room is too hot (above +30°C) or too cold (below +10°C), the refrigerator may not work correctly, often turn off or not turn off at all.