The situation when the refrigerator works sometimes and notcan unbalance any owner of the equipment. You open the door to take food, and it’s already warm inside, although an hour ago the compressor was humming smoothly. Or vice versa: the unit is silent for too long, and you begin to doubt whether it turns on at all. Such “blinking” of modes is not just an inconvenience, but a signal that the control or cooling system has failed.
Modern models, be it Indesit, Bosch or LG, are equipped with complex electronics that can behave unpredictably during surges voltage or overheating. However, the good old “Atlanta” or “Biryusa” with mechanical control are also subject to similar vagaries. Understanding why the refrigerator turns on and off why does the refrigerator turn on and off at irregular intervals, will help you save money on calling a technician, or at least correctly describe the problem to a specialist.
In this article we will analyze in detail the main reasons for unstable operation. We will touch upon both trivial operating errors and serious technical malfunctions that require intervention cooling system. It is important not to ignore the first symptoms, since cyclic starting and stopping can quickly lead to food spoilage and failure of an expensive compressor.
Power supply problems and power surges
The most commonplace, but often ignored reason is unstable voltage in the network. If the refrigerator sometimes works, sometimes it doesn’t, the first thing you should do is check the outlet. In older homes, the wiring may not be able to withstand the load, especially if powerful energy consumers are turned on at the same time. The contact in the socket may be weakened, which leads to periodic loss of power.
The electronics of modern models are extremely sensitive to changes. If there is a sudden surge in voltage, the built-in protection can force the unit to shut down to prevent the control board from burning out. After the network parameters are normalized, the equipment can start again, creating the illusion of serviceability until the next surge repeats the cycle.
⚠️ Attention: Continuous voltage surges can irreversibly damage the windings of the electric motor. Use surge protectors or stabilizers if the lights in your area often “flashing”.
For diagnostics, try plugging the refrigerator into a different outlet, preferably in another room, and monitor its operation during the day. It is also worth checking the condition of the power cord and plug: melting or blackening of the plastic will indicate poor contact, which heats up and temporarily breaks the circuit.
Do not forget about the internal wiring of the device itself. Vibrations during compressor operation over time loosen the terminal connections inside the housing. If the contact comes off, the engine stalls, and after cooling or changing the position of the housing it can start again.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” that decides when to start compressor. If this element fails, the refrigerator begins to operate chaotically. In mechanical models, the thermostat contacts may burn or stick. As a result, the unit either does not turn on at all, or works without interruption, or, most often in our case, turns on for a short time and immediately turns off.
In models with a system No Frost and electronic control, the temperature is monitored by sensors (thermistors). They change their resistance depending on the heat. If the sensor “lies” and sends a signal to the control module that it is already -25°C in the chamber, although in fact it is +5°C, the compressor will not start. Conversely, a false overheating signal will cause the motor to operate in emergency mode.
How to check the thermostat without instruments
Remove the thermostat and short-circuit the two wires coming from it directly. If the refrigerator runs continuously, the problem is in the thermostat. Do not leave the device in this mode for a long time!
A common cause is incorrect setting or misalignment of the capillary tube of the mechanical thermostat. If it does not fit tightly to the evaporator, heat exchange is disrupted and the sensor does not read the temperature correctly.
- 🔍 Symptoms: The refrigerator hums for 1-2 minutes and turns off, or is silent for hours with the light turned off inside.
- 🔧 Actions: Check the temperature settings, try turning them turn the regulator knob to the extreme positions.
- ❄️ Nuance: In two-compressor models (for example, Atlant or Liebherr), the sensor of one of the chambers often fails.
Starting protection relay and problems with the compressor
If you hear a click, after which the refrigerator hums for a few seconds, and then a second click is heard and silence sets in, this is a classic sign of a malfunction of the starting protection relay or the compressor itself. The relay is responsible for supplying current to the motor windings when starting. When it breaks, the engine cannot gain the required speed and the protection de-energizes the system again.
The compressor itself may be in good working order, but “stuck” (jammed) due to exhaustion or lack of lubrication. In this case, it tries to start, hums, heats up, and the thermal relay turns it off. After some time, when the metal has cooled, the cycle repeats. This condition is called “short cycle operation.”
☑️ Diagnostics of refrigerator sounds
Replacing the start relay is a relatively simple and inexpensive procedure, which can often be done independently by selecting an analogue for your model, for example, Danfoss or Indesit. However, if the problem is in the motor windings or mechanical jamming of the piston group, the compressor will need to be replaced, which is a complex and expensive repair.
It is important to avoid prolonged operation in this mode. Frequent attempts to start with a jammed rotor can lead to an interturn short circuit and complete combustion of the motor, which will make further repairs economically unfeasible.
Clogged capillary tube or freon leak
One of the hidden reasons why the refrigerator turns on and offis a circulation disorder refrigerant. If “ice” or technical blockage has formed in the system (for example, moisture has entered or an oil plug has formed), the pressure in the circuit increases sharply. The compressor operates with overload until the thermal protection is triggered.
After cooling (after 15-40 minutes), the protection releases, the compressor starts again, but due to the lack of normal freon current, the cold does not increase. The cycle repeats. Visually, this may manifest itself in the fact that the condenser (grid at the back) heats up only partially or unevenly.
| Symptom | Probable cause | Nature of operation |
|---|---|---|
| Buzzing for 5-10 minutes, rest 30 min | Clogged capillary system | Cyclic, with overheating |
| Works constantly, no cold | Freon leakage | Continuous |
| Clicks and is silent | Relay/compressor malfunction | Short pulses |
Freon leak usually leads to the refrigerator working continuouslytrying to gain temperature. However, in some cases, when there is critically little refrigerant remaining, the sensors may behave incorrectly, or the compressor will go into protection due to overheating, since freon also cools the motor.
To eliminate blockages, it is necessary to purge the system with nitrogen and replace the filter-drier, and if there is a leak, search for the location of the damage and refill. These works require special equipment and skills, so you can’t do it without a specialist.
The influence of the No Frost mode and the defrosting system
In refrigerators with the system No Frost not only the compressor, but also the evaporator defrosting system is responsible for temperature stability. If the defrost heating element, timer or defrost sensor fails, a “coat” of ice will build up on the evaporator. The fan stops driving out cold air, and the chamber becomes warmer.
In such situations, the compressor can operate as usual, but due to the fact that cold does not enter the chamber, the temperature sensor does not give the command to stop. Or, if ice blocks the fan, the electronics may cause the unit to fail, and it will turn on and off in emergency mode.
Often owners notice that the problem appears after defrosting or prolonged operation in conditions of high humidity. Ice can block the damper that regulates the air flow between the freezer and refrigerator compartment.
System diagnostics No Frost requires partial disassembly of the rear panel of the freezer. It is necessary to visually assess the amount of ice on the evaporator. If it is covered in ice and the fan is standing still, look for the cause in the defrost circuit.
Operation errors and external factors
Before committing a breakdown, eliminate the human factor. The refrigerator works sometimes or not often due to simple overheating. If the unit is standing close to the wall, next to a radiator or stove, heat exchange is disrupted. The compressor overheats and goes into protection.
The loading density also affects. If you put a large pot of hot soup in the chamber, the refrigerator will work hard trying to cool the volume. After reaching the temperature, it may turn off, but due to inertia and residual heat, the sensor may start the cycle again ahead of time.
Don't forget about the level. If the refrigerator is not level, the doors may not close tightly. Warm air constantly flows inside, causing the equipment to work in jerks. Check the legs and tightness of the seal.
Finally, the “Super Freeze” or “Vacation” mode, left on accidentally, also changes the operating algorithm, forcing the compressor to turn on more often or less frequently than usual.
When you need to call a technician
If simple methods like defrosting on day, checking the socket and cleaning the capacitor did not help, the problem is probably of a technical nature. Self-repair of the cooling system is dangerous and requires a license to work with freons.
A technician is needed if:
- 🛑 The compressor gets very hot and smells burnt.
- 🛑 You hear gurgling or hissing inside the pipes (a sign of a leak).
- 🛑 Swelling or traces of corrosion are visible on the back wall.
⚠️ Attention: Do not try to break through the blockage with a sharp wire yourself! You can damage the thin-walled evaporator tubes, which will lead to a complete loss of circuit tightness.
Professional diagnostics using a pressure manifold and tester will allow you to accurately determine what the cause is: electronics, mechanics or refrigerant leak. Sometimes it is easier to replace the entire assembly than to look for a microscopic crack.
Why does the refrigerator turn on immediately after turning off?
This may indicate sticking thermostat contacts or a malfunction of the electronic control module, which sends incorrect signals to start the engine. It is also possible that the temperature in the chamber has not yet had time to drop to the desired value due to a leak in the seal.
Can the refrigerator operate jerkily due to an inverter compressor?
Inverter models (LG Linear Cooling, Samsung Digital Inverter) should not click and turn off completely. They change power smoothly. If such a refrigerator behaves like a regular one (on/off), it means that the inverter control board has failed.
How long can you operate the refrigerator intermittently?
It is highly not recommended. Unstable operation leads to defrosting of food and the growth of bacteria. In addition, frequent hot starts quickly kill the life of the compressor. It is better to turn off the device before the technician arrives.
Does replacing the seal affect the operating mode?
Yes, if the old seal allowed air to pass through, the compressor worked more often. After replacement, the mode may change: the unit will gain temperature faster and stand idle longer. This is normal.