The situation when a household refrigerator starts working in heavy duty mode is familiar to many owners of a modern technology. The device hums almost non-stop, trying to maintain the set temperature, which immediately affects energy bills. Often, users notice the problem only after receiving a bill from the electricity supplier or when the food in the freezer begins to become covered with excess frost.
Understanding why the unit turns on too often is the first step to preventing serious damage. Compressor, which is the heart of the system, experiences enormous overloads during this mode of operation. If the cause of the failure is not eliminated as soon as possible, the motor resource may be exhausted long before the service life declared by the manufacturer expires.
In this article we will analyze in detail the main technical and household reasons for the unstable operation of climate control equipment. You will learn in which cases you can cope on your own, and when the intervention of a qualified technician with specialized equipment is required.
Violation of the chamber seal and wear of the seal
The most common and easily eliminated reason for frequent switching on is the loss of tightness of the internal circuit. Through the cracks in the doorway, warm air from the room constantly flows inside, causing the temperature sensors to signal the need for cooling. The main culprit here is rubber seal, which dries out, cracks or deforms over time.
Even a microscopic gap, invisible to the eye, can upset the temperature balance. Warm air hitting the evaporator instantly turns into condensation and ice, blocking the normal circulation of air flow. The system No Frost under such conditions tries to compensate for heat loss by starting the motor-compressor at full speed.
To check the tightness there is a simple and effective method that does not require tools. Take a sheet of A4 paper or a banknote and clamp it with the refrigerator door around the entire perimeter. If the paper is removed easily, without noticeable rubber resistance, it means that the seal is broken.
Sometimes you can restore the elasticity of the seal by warming it up. Carefully run a hairdryer along the entire length of the rubber, then press the door tightly and let it cool while closed. If the rubber has visible tears or has become too hard, it will need to be completely replaced with an original part.
⚠️ Attention: When installing a new seal, be sure to let it “sit” at room temperature for at least 24 hours so that the material straightens and takes the correct shape before installation.
Malfunctions of the thermostat and sensors temperature
The thermostat (thermostat) is a device that is responsible for turning the compressor on and off depending on the temperature inside the chambers. If this element fails, it may send incorrect signals to the control board. For example, the sensor “thinks” that it is warm in the chamber, although in fact it is already cold there, and continues to keep the compressor on.
In modern models with electronic control, instead of a mechanical thermostat, thermal sensors (NTC resistors) are used. Their resistance changes depending on temperature. If there is an open circuit or a change in the nominal resistance, the controller receives false data. This leads to the fact that the refrigerator works without stopping, trying to cool the chamber to a non-existent value.
Diagnostics of the thermostat in mechanical models is often carried out by the method of elimination. If the compressor does not turn off when the temperature drops to a minimum, but works when the contacts are forced to close, the problem is in the regulator itself. Electronic models require testing with a multimeter and checking the readings with reference values for a specific model Indesit, Atlant or Bosch.
Replacing a thermostat usually does not cause difficulties for home craftsmen, but requires compliance with safety precautions. Before starting work, you must completely de-energize the unitunplug the plug from the socket to avoid electric shock.
Problems with refrigerant: freon leakage and blockages
One of the most serious technical problems, causing continuous operation of the engine is a refrigerant leak. Freon circulates in a closed loop, transferring heat from the inner chamber to the outside. If a microcrack or a corrosion hole has formed in the tubes, the gas gradually evaporates, and the cooling efficiency drops to zero.
When the freon level is low, the compressor is forced to work at the limit of its capabilities, trying to gain the required pressure, but since there is little gas, the temperature does not drop to the set point. The thermostat does not give the command to turn off, and the unit hums for days. An indirect sign of a leak may be insufficient cooling of only one of the chambers or the appearance of swelling on the side walls.
Another problem in the circulation system is Clogged capillary tube. Oil breakdown products or moisture entering the system can turn into an ice plug or mechanically block a narrow channel. The pressure in front of the compressor drops, and behind it increases, which also leads to continuous operation.
Is it possible to refuel the refrigerator yourself?
Self-refueling without eliminating the cause of the leak is a temporary measure. The freon will escape through the hole again, and the compressor will burn out due to operation in a vacuum or overload. It requires searching for the leak, soldering and evacuating the system.
To diagnose leaks, technicians use leak detectors or the nitrogen pressure test method. At home, it is almost impossible to detect where the gas is escaping, so if you suspect a freon leak, it is better to immediately contact a service center.
Wear of the compressor and start relay
The compressor is the most expensive and complex component of the refrigerator. Over time, its mechanical parts wear out and compression (discharge pressure) decreases. The engine starts to run “idle”, without creating the necessary pressure in the system, which is why the refrigerator cannot enter mode and turn off.
Often the problem lies not in the motor itself, but in start-protection relay. This small element is responsible for starting the engine and protecting against overloads. If the relay contacts are burnt or the mechanism is stuck, the compressor may hum, but not start, or work intermittently, constantly turning on and off at short intervals.
You can determine a relay malfunction by a characteristic click when you try to start. If after a click the motor does not start, and after a while a second click is heard, the relay needs to be replaced. This is a consumable material that is inexpensive and can be changed quite easily.
The table below shows the main symptoms of compressor group malfunctions:
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Buzzing, but not cold | Freon leak or loss of compression | Call a technician, pressure diagnostics |
| Clicks and turns off | Faulty start relay | Replacement relay |
| The housing gets very hot | Motor overload or contamination | Cleaning the capacitor, checking the windings |
| Works without interruption | Wear of the piston group | Replacing the compressor |
Influence of the external environment and operating conditions
Not The reason always lies in a breakdown. Often, users themselves create conditions under which the refrigerator is forced to work in increased mode. One of the main factors is the room temperature. If the room is hot (above +25..+30°C), heat exchange between the condenser and air is difficult.
The condenser (black grille on the back or panels on the sides) must transfer heat efficiently. If the refrigerator is located close to the wall, in a niche or next to the stove/radiator, the hot air has nowhere to go. It circulates around the body, heating it, and the cooling efficiency drops.
It is also worth considering the load volume of the chambers. A fully loaded refrigerator takes longer to cool food, especially if you put a warm pot of soup inside. However, an empty refrigerator also works worse, since food serves as cold accumulators. The optimal load is about 70% of the volume.
☑️ Checking the installation conditions
Class devices N (normal) are designed to operate at temperatures from +16 to +32°C. If you use them in an unheated garage in winter or on a sunny terrace in summer, breakdown is inevitable.
Errors in settings and “Super Freeze” mode
Sometimes the reason for continuous operation is trivial and lies in the user’s carelessness. Many modern refrigerators are equipped with a “Super Freeze” or “Quick Cooling” function. When this mode is activated, the compressor runs continuously for several hours (usually up to 8 hours) to quickly freeze a large mass of food.
If you accidentally turned on this function or forgot to turn it off (in models without auto shut-off), the refrigerator will freeze until it stops. Check the control panel: if the snowflake indicator or the inscription Superis on, the mode is active.
It is also worth checking the temperature settings. If you have set the minimum possible temperature (for example, -24°C in the freezer or +2°C in the refrigerator), the unit will strive to reach these values, working almost without interruption, especially in the summer.
⚠️ Attention: Long-term operation in the “Super Freeze” mode without load (empty freezer) can lead to freezing of the air exhaust channels and the exit from building defrost systems.
Diagnostics and action plan in case of malfunction
If you are convinced that the seal is intact, the “Super Freeze” mode is turned off, and the refrigerator is positioned correctly, but the problem persists, it is necessary to conduct a more in-depth diagnosis. Start with a visual inspection: is there any oil under the refrigerator, is the condenser covered with a thick layer of dust.
Dust on the condenser radiator acts as a heat insulator, preventing freon from cooling. Cleaning the condenser with a vacuum cleaner or soft brush is a mandatory procedure that must be carried out at least once a year. This can reduce energy consumption and noise by 15-20%.
In the case when simple methods do not help, and you hear that the compressor is working “pull”, it is better Do not experiment with independently replacing components that require working with freon. Professional repairs include vacuuming the system, which cannot be done without a special pump.
Frequently asked questions (FAQ)
Is it normal for a new refrigerator to work without stopping for the first day?
Yes, this is absolutely normal. After turning on for the first time, an empty refrigerator requires time (from 2 to 24 hours) to cool the entire internal volume and reach the set temperature. At this time, the compressor may not turn off.
Why does the refrigerator hum immediately after defrosting?
If you have just defrosted the unit and turned it on, it will work for a long time, since the walls and food are warm. If it is completely defrosted (room temperature) and buzzes for more than 5-6 hours without a break, this is a sign of a malfunction.
Can frequent switching on be due to power surges?
Yes, unstable voltage in the network can cause malfunctions in the electronic control module, which leads to chaotic switching on of the compressor. In such cases, it is recommended to use a voltage stabilizer.
What to do if, after replacing the thermostat, the refrigerator does not turn off?
Perhaps the wrong thermostat is installed (with different temperature characteristics) or the length of the capillary tube of the sensor is incorrectly set. Also, the problem may not be in the thermostat, but in a freon leak.