The situation when the refrigerator works without interruptionis familiar to many owners of household appliances. The hum of a compressor, which does not subside for hours and sometimes days, causes fair concern. This not only creates a constant noise background in the apartment, but also signals that the unit is operating in extreme mode, which inevitably leads to increased energy consumption.
In most cases, the reason lies in a violation of heat exchange or improper operation, but the problem cannot be ignored. Motor-compressor, operating non-stop, is subjected to colossal load, the life of its parts is depleted many times faster than during normal cyclic operation. If you do not intervene in time, a simple adjustment can turn into an expensive replacement of expensive components.
In this article we will analyze in detail why compressor turns on too often or does not turn off at all. You will learn how to distinguish normal operation in hot weather from a technical malfunction and what steps need to be taken to diagnose the cooling system.
External factors and operating conditions
Before looking for a breakdown inside the housing, it is necessary to assess the environment. Often the reason for intensive work lies in a banal violation of the temperature regime of the room. If refrigerator stands close to a wall or in a niche where there is no air circulation, the radiator on the rear wall cannot effectively transfer heat. As a result, the unit is forced to work longer to achieve the specified parameters.
Another critical factor is the high air temperature in the room. In summer, when the thermometer rises above +30°C, it is physically more difficult for the refrigerator to cool the chambers. In such conditions, an increase in the operating time of the compressor is a natural protective reaction a system trying to compensate for external overheating.
It is also worth checking the location of the equipment relative to heat sources. Heating radiators, stoves, ovens and direct sunlight create local areas of high temperature that disorientate thermostat.
⚠️ Attention: Placing the refrigerator closer than 10-15 cm from the wall or heating devices is guaranteed to lead to overheating of the condenser and continuous operation of the motor.
Do not forget about the tightness of the seals. If the rubber cuff on the door has become dry, dirty or damaged during washing, warm air from the outside constantly enters the chamber. The system detects an increase in temperature and forces the compressor to work without rest.
The influence of the “Super Freeze” mode and fresh food
A frequent cause of “endless” operation is the human factor, namely the activated function Super Freeze (super freezing). This mode is designed to quickly freeze a large volume of food and forcibly keeps the compressor on, ignoring the temperature sensor readings.
If you have loaded a lot of warm food into the chamber or a large amount of fresh vegetables and fruits that contain moisture, the refrigerator will take a significant amount of time to remove the heat. When moisture freezes, it releases energy, which further loads the system. In a normal scenario, after reaching the target temperature, the mode should turn off automatically or manually.
However, if the button was pressed accidentally (for example, by children or pets) or the electronic module is frozen, the refrigerator will freeze until it stops. In models with electronic control, a failure in the control unit can simulate a command for permanent freezing.
Problems with the condenser and ventilation
The condenser is a grille (usually black) located on the back wall or along the perimeter of the doors (in hidden models). Its job is to cool the refrigerant. If this grille is covered with a layer of dust, pet hair or fluff, heat transfer is critically impaired. Dirt acts as an insulator, preventing heat from escaping into the atmosphere.
In models with the system No Frost a fan is responsible for air circulation. If its blades are dirty or the fan motor works intermittently, cold air does not enter the chamber, and the temperature sensor continues to “scream” about the lack of cold. In response to this, the compressor wears out.
Cleaning the condenser is a simple but effective procedure. It is enough to carefully vacuum the grille or use a soft brush. After cleaning, you will notice that the refrigerator begins to work more quietly and take longer breaks.
Malfunctions of the thermostat and sensors
The thermostat (thermostat) is the “brain” that makes the decision to turn the compressor on and off. In mechanical models it is a simple “twist” with a tube, in electronic models it is complex sensors. If the thermostat is out of order, it may simply not open the electrical circuit, even when arctic cold has already been reached in the chamber.
In electronically controlled refrigerators, the defrost sensors evaporator is responsible for the temperature. If one of them shows incorrect data (for example, due to oxidation of contacts or broken wiring), the control board receives a false signal that the chamber is warm. As a result, the motor hums continuously.
| Symptom | Probable cause | Action |
|---|---|---|
| The refrigerator does not turn off, it is very cold in the chamber | Sticking thermostat contacts | Replacing the thermostat |
| The motor hums, but there is no or little cold | Sensor malfunction or freon leak | Diagnostics by a master |
| The compressor often turns on for a short time | Leakage or overheating | Checking the seal and ventilation |
Diagnostics of the thermostat at home is possible, but requires caution. In mechanical models, you can temporarily close the contacts to check whether the motor will start, but to accurately check for a break, you need a multimeter.
Refrigerant leakage and problems with the compressor
If the refrigerator runs constantly, but the temperature in the chambers does not drop below +10...+15°C, this is a sure sign freon leaks. The refrigerant circulates through the system, picking up heat. When its quantity drops below a critical level, the pressure in the system drops, and the compressor tries to compensate for the lack of cold by continuous operation.
The second extreme is the loss of performance of the compressor itself. Over time, the valves inside the motor wear out, and it cannot create the necessary pressure to compress the gas. As a result, the unit hums, heats up, but does not cool. In such cases, it is often necessary to replace the motor-compressor.
If there is a leak, you can often notice oily spots under the refrigerator or in the compressor area, as freon circulates along with the oil. Swelling of the back wall inside the freezer may also be observed.
Features of operation in winter
In winter, the situation may be the opposite, but also associated with continuous operation. If the refrigerator is in an unheated room (balcony, cottage) or near a window where the temperature drops below +10...+15°C, problems may arise. In some models, the oil in the compressor thickens, and the thermostat “thinks” that the room is already cold, so it does not turn on the motor. But in other cases, if the mode is enabled No Frost, the system may behave incorrectly.
However, more often in winter the problem is due to the fact that users forget to turn off the super freezing mode after guests arrive. It is also worth checking whether cold air from the window is blowing directly onto the thermostat if it is located near the door.
⚠️ Attention: Operating the refrigerator at an ambient temperature below +10°C (if climate class SN or SN-T is not provided) can lead to rapid failure of the compressor and disruption of oil circulation.
If your refrigerator is designed to operate over a wide temperature range, check the settings. It may make sense to switch it to “economy” mode or “vacation” mode if you rarely open the doors.
Frequently asked questions (FAQ)
How long should a refrigerator operate normally?
Under normal conditions, the operating cycle looks like this: the compressor works for 10-20 minutes, rests for 20-40 minutes. The working time ratio is approximately 30-40%. If the refrigerator works more time than it rests, this is a cause for concern.
Why does a new refrigerator work constantly on the first day?
When first turned on or after a long defrosting, the refrigerator requires time (from 2 to 12 hours) to cool the entire volume of chambers and food to the set temperature. During this period, continuous operation of the compressor is absolutely normal.
Is it dangerous if the refrigerator hums nonstop?
Yes, it is dangerous. Besides high electricity consumption, continuous operation leads to overheating of the motor windings, destruction of the oil and eventual breakdown of the compressor. The starting relay may also burn out.
Is it possible to replace the thermostat yourself?
In mechanical models - yes, if you have the skills to work with tools and understand electrical circuits. In models with electronic control and sensors (NTC), it is better to contact a specialist, as precise calibration is required.