The situation when the refrigerator often turns off and onis familiar to many owners of household appliances. This operating mode, called short cycling, is not normal and indicates a control system failure or compressor overload. In normal mode, the unit must operate for a long time, gaining the desired temperature, followed by a long pause to rest the engine.
Ignoring the problem can lead to complete failure of the expensive one. compressor. Frequent starts create peak loads on the motor windings, causing them to overheat and melt the insulation. In addition, this significantly increases energy consumption, which is immediately reflected in utility bills.
In this article we will analyze in detail the main reasons for unstable operation, self-diagnosis methods and cases when you cannot do without calling a technician. Understanding the principles of operation refrigeration circuit will help you quickly identify a malfunction and avoid unnecessary panic.
Normal duration of refrigerator operation cycles
Before sounding the alarm, you need to understand what is considered normal for your model of equipment. The standard operating cycle of a modern compressor is from 15 to 30 minutes, followed by a pause of a similar or longer duration. However, these indicators may vary depending on chamber loading and the external temperature.
If you have just placed a large amount of warm food in the refrigerator, the active operation time may increase. In this case, the unit works for wear and tear, trying to cool the internal volume. The mode is considered critical when pauses between starts last less than 5-7 minutes, and the compressor itself hums for only 2-3 minutes.
Modern inverter models can work differently, maintaining the temperature by changing the speed of rotation of the motor, and not completely turning it off. Therefore, for an accurate assessment of the situation, always refer to the technical data sheet of your device.
Incorrect installation and heat transfer disturbance
One of the most commonplace, but common reasons for frequent switching on is a violation of operating rules. If the refrigerator is installed close to the wall or in a niche without gaps, the air circulation around condenseris disrupted. The heat is not removed effectively, and the sensors detect an increase in temperature, causing the motor to run jerkily.
It is also worth checking the condition of the rubber seals on the doors. If they are worn out, dirty or deformed, warm air constantly enters the chamber. The compressor tries to compensate for the heat influx, but due to leakage it cannot achieve the set parameters and turns off due to a timer or overheating.
⚠️ Attention: The distance from the back wall of the refrigerator to the wall must be at least 7-10 cm. This is the minimum requirement for free air convection.
To fix the problem, do the following Actions:
- 🔍 Move the unit away from the wall and check whether the rear grill is overheating.
- 🧼 Wash the seal with soapy water and check the tightness of the door.
- ❄️ Make sure that the products do not lie flush against the back wall chambers, blocking the circulation channels.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” of the refrigerator, which gives the command to turn the compressor on and off. If this element fails, it may transmit incorrect signals. For example, the contacts stick in the closed position or, conversely, open too early, not allowing the chamber to cool down.
In models with a system No Frost and electronic control, the role of a mechanical thermostat is performed by air sensors. Their readings may be distorted due to oxidation of contacts or broken wiring. As a result, the control board receives false information about the temperature and runs cooling cycle chaotically.
Thermostat diagnostics often require special tools, but the initial check can be done visually. If you do not hear a characteristic click when you turn the control knob, or if the refrigerator does not turn on when you twist the knob to the “maximum” position, the problem is most likely there.
How to check the thermostat with a multimeter?
To check, you need to remove the thermostat, immerse its sensitive tube in cold water with ice and ring the contacts. When cooling, the circuit should open (or close, depending on the type), which will be shown by the device.
Problems with the starting relay and compressor
The starting relay is responsible for starting the compressor motor. If a short circuit or contact wear occurs in this unit, the motor may try to start, make a clicking sound and immediately stall. After some time, the thermal protection is triggered, cools down, and the cycle repeats again.
The compressor itself can also be the cause of instability. Interturn short circuit of the windings leads to a sharp increase in current consumption. The protective relay detects the overload and emergency turns off the power to prevent a fire or complete combustion of the motor.
The table below shows the main symptoms of motor and relay malfunctions:
| Symptom | Probable cause | Actions |
|---|---|---|
| Clicking and buzzing for 2-3 seconds | Compressor jamming | Replacing the compressor |
| Frequent clicks without buzzing | Faulty start relay | Replacing the relay |
| There is a hum, but it turns off | Overheating or low voltage | Checking the network and ventilation |
If you hear a loud metallic knock or ringing when you try to start, further operation refrigeration unit is prohibited. This may indicate destruction of the internal mechanical parts of the compressor.
☑️ Diagnostics of the start relay
The influence of the No Frost defrosting system
In refrigerators with the system No Frost Frequent switching on may be associated with a malfunction of the defrost system. If the evaporator heating element is burnt out or the defrost timer is jammed, a “coat” of ice builds up on the evaporator. The air stops circulating, the temperature sensor does not see the cold and requires continuous operation of the compressor.
However, if the compressor does turn off, but the intervals are too short, the overheating protection may be triggered due to the fact that the motor is running non-stop, trying to break through the ice plug. In some models, if there are errors in the defrosting system, emergency operation is activated.
Signs of problems with defrosting are also:
- 💧 Water on the floor under the refrigerator.
- ❄️ Audible cracking of ice inside the chamber.
- 🌡️ Uneven cooling of food.
⚠️ Attention: Attempts to defrost the refrigerator with a knife or hairdryer in the presence of electronics can lead to damage to the plastic parts of the evaporator or a short circuit.
Failures in the electronic control module
Modern refrigerators are controlled by complex electronics. Voltage surges in a household network can lead to glitches on the control board. The controller can randomly send signals to start the compressor, ignoring sensor readings.
Often the problem is solved by a complete reboot of the system. To do this, you need to unplug the refrigerator from the outlet for 15-20 minutes. This will clear errors in the controller memory and restart the software.
If after a reboot the problem “the refrigerator often turns off and on” persists, the control module itself or one of its components (capacitors, triacs) has probably failed. In this case, professional resoldering or board replacement is required.
Frequently asked questions (FAQ)
Is it possible to replace the starter yourself? relay?
Yes, if you have basic skills with tools. The relay is usually mounted on the side of the compressor and can be removed with a simple movement. The main thing is to buy an exact copy for your compressor model.
Why does the refrigerator turn on immediately after being turned off?
This is a sign of stuck thermostat contacts or a malfunction of the electronic sensor. Freon leakage is also possible, due to which the temperature does not have time to drop to the desired level in one cycle.
Does the network voltage affect the frequency of switching on?
Yes, at low voltage it is difficult for the compressor to start, it hums and quickly turns off due to thermal protection. It is recommended to use a voltage stabilizer.
What to do if the compressor is hot to the touch?
A hot compressor (up to 70-90 degrees) in operating mode is normal. But if it is so hot that it is impossible to touch it, and the refrigerator clicks and does not start, immediately unplug the appliance.