The situation when the compressor of the refrigeration unit hums for hours without switching to mode peace, is familiar to many owners of household appliances. This phenomenon is alarming not only because of the intrusive noise, but also because of the sharp rise in energy bills. Understanding why the refrigerator does not stopis the first step to troubleshooting and preventing costly repairs.
In most cases, continuous operation of the motor indicates that the set temperature is not reached inside the chamber, and the control system forces the compressor to work to wear out. This can be caused either by simple user inattention or by serious technical defects in the refrigerant circulation system or electronic control board.
It is important to note that modern models with inverter motors can work longer than usual, but they still must periodically reduce speed or stop. If you hear a characteristic shut-off click, but after a few seconds the motor starts again, or it hums monotonously for days, ignoring the thermostat commands, you need to look for the reason.
Violation of tightness and operating errors
The most common reason why the refrigerator does not turn off lies not in the breakdown of parts, but in a violation of the thermal balance. If heat constantly enters the chamber from the outside, temperature sensor records a deviation from the norm and sends a signal to start the compressor. Often, users themselves create conditions for equipment overload.
One of the main mistakes is placing hot or warm foods in the refrigerator. The thermostat perceives a sharp rise in temperature as a signal for active operation. In addition, a loosely closed door or a damaged seal allows warm air from the kitchen to penetrate inside, causing the unit to work idle.
⚠️ Attention: If you notice that the rubber seal does not fit along the entire perimeter, do not try to heat it thoughtlessly with a hairdryer - this may damage the structure of the material. It is better to replace the element with an original one.
It is also worth checking whether the door is pressed by a foreign object. Sometimes even a small piece of packaging or a misaligned shelf can prevent a tight seal. In modern models with a system No Frost this is monitored by a special sensor that can emit a sound signal, but in older models you will only know about this by the freezing of ice and the endless operation of the motor.
- 🔥 Installing hot pots or dishes that have not cooled down to room temperature.
- 🚪 The door is not tightly closed due to overfilling or foreign objects.
- ❄️ Wear of the magnetic seal, allowing warm air to pass through.
- 🌡️ Placing the refrigerator too close to heat sources (radiators, stoves).
Malfunctions of the thermostat and sensors
If The seal is fine, the next suspect is the thermostat. This mechanical or electronic component is responsible for controlling the temperature inside the chambers. When thermostat fails, it can “stick” in the “on” position, constantly sending a signal to start the compressor, even if the required cold has already been achieved inside.
In electronically controlled refrigerators, temperature sensors (thermistors) perform the role of a thermostat. They transmit data to the control module. If the sensor “lies” and shows that the chamber is +10°C instead of the required +4°C, the “brains” of the refrigerator will drive the motor, trying to cool the air. Diagnosis of such faults requires a multimeter and a resistance check.
Often the problem lies in oxidation of the contacts or a break in the wiring going to the sensor. In this case, the system may perceive the absence of a signal as an emergency and turn on the intensive cooling mode or, conversely, not start the compressor at all. However, a scenario with continuous operation is more likely when the readings are distorted upward.
How to check a mechanical thermostat
To check a mechanical thermostat, you need to remove it and immerse the sensitive tube in a container with water at a temperature of about 10-12 degrees. If the contacts do not open (the dial continues to beep), the thermostat is faulty and requires replacement. Be careful with the refrigerant inside the tube!
Problems with the defrosting system in No Frost models
Owners of equipment with the system No Frost often face a situation where the refrigerator does not turn off due to the “overgrowing” of the evaporator with ice. The automatic defrost system consists of a heater, a timer (or electronic module) and a defrost sensor. If one of these elements breaks, the ice stops melting.
The frozen coat of ice on the evaporator blocks the circulation of cold air. The fan moves the air, but it cannot pass through the ice shell to the food. The temperature sensor in the chamber detects heat and requires the compressor to operate. As a result, the motor works without stopping, trying to break through the ice blockade, but to no avail.
An indirect sign of such a malfunction may be that the food is still holding in the freezer compartment, but it is already warm in the refrigerator compartment. Or you may notice that water has stopped dripping from the drainage hole during the period of expected defrosting.
- 💧 Burnout of the evaporator defrost heating element.
- ⏱️ Failure of the defrost timer or fuse.
- 🌡️ Malfunction of the defrost sensor (defrost timer).
- 🧊 Clogged drainage channel, icing of the air ducts.
Freon leakage and compressor malfunction
A more serious reason why the refrigerator does not turn off is a leak in the refrigeration circuit. If this occurs freon leak, the refrigerant in the system becomes insufficient to create the required pressure and temperature. The compressor runs continuously, trying to compensate for the lack of gas, but cannot achieve the target values.
When there is a leak, you can often notice that the condenser (grid at the back) remains only partially cold or warm. Another sign may be swelling of the inner wall of the refrigerator (in models with a steam evaporator) or the appearance of oily spots under the unit. In such cases, simply pumping up freon will not help - you need to search for the leak and solder.
Another possible reason is the loss of performance of the compressor itself. Wear of the piston group or valves leads to the fact that the engine hums, but does not create the required pressure in the system. It works at the limit of its capabilities, consuming a lot of electricity, but not cooling the chambers.
| Symptom | Probable cause | Required actions |
|---|---|---|
| Compressor is hot, condenser is cold | Leak freon or clogged capillary | Call a technician to find a leak |
| Loud knocking at startup, then a buzzing | Malfunction of the start relay | Replace the relay (you can do it yourself) |
| Ice coat on the back wall | No Frost system malfunction | Checking the heating element and defrost sensors |
| The refrigerator hums, but does not cool | Loss of tightness or compressor | Diagnostics of pressure in the circuit |
The influence of the external environment and installation conditions
Do not forget about external factors. If the refrigerator is installed in a niche where ventilation is poor, or is in direct sunlight, it is physically difficult for it to give off heat. Condenser overheats, cooling efficiency drops, and the motor is forced to work longer.
In the summer, when the room temperature exceeds +30°C, refrigerators can operate almost non-stop. This is a normal physical reaction: the temperature difference between the chamber and the environment is too great. However, even in hot weather, the cycles must be maintained, albeit with a reduced rest time.
⚠️ Attention: Make sure that there is a gap of at least 5-7 cm between the back wall of the refrigerator and the kitchen wall. The absence of a gap critically disrupts heat transfer.
The temperature in the room also matters. If the refrigerator is placed in an unheated room in winter, the oil in the compressor may thicken and the sensors will not work correctly. Many models are not designed to operate at temperatures below +10°C.
☑️ Checking the installation conditions
Failures in the operation of the electronic control module
In modern models, such as LG, Samsung or Bosch, the entire process is controlled by an electronic module. Power surges, moisture, or manufacturing defects can cause the board to glitch. In this case, the relay on the board may stick in a closed state, constantly supplying voltage to the compressor.
It is difficult to diagnose such a malfunction at home. Often a module needs to be re-flashed or completely replaced. If you notice that the indication on the display behaves strangely (flashes, shows non-existent error codes), this is a sure sign of problems with the “brains” of the refrigerator.
Sometimes a simple error reset by a long disconnection from the network (for 30-40 minutes) helps. If, after turning on the network and setting the minimum temperature, the refrigerator goes back into continuous operation, most likely, the intervention of a specialist with diagnostic equipment will be required.
Frequently asked questions (FAQ)
How long should a refrigerator operate normally?
Under normal conditions, the operating cycle is approximately 15-20 minutes and 30-40 minutes of rest. The ratio of work time to rest time should be approximately 1:2 or 1:3. If the refrigerator works for 40 minutes and rests for 10, this is a cause for concern.
Is it possible to operate the refrigerator if it does not turn off?
For a short time - it is possible, but not recommended. Long-term operation without stopping leads to overheating of the compressor windings, drying out of the oil and rapid wear of rubbing parts. This can shorten the life of the motor several times.
Why did the new refrigerator immediately start working without stopping?
When turned on for the first time, the refrigerator takes a long time (up to 24 hours) to cool the entire volume of the chambers and products to the set temperature. During this period it can work continuously. If the mode does not return to normal after a day, check the thermostat settings.
Is the burning smell dangerous during continuous operation?
Yes, this is a dangerous sign. The smell may come from overheating wiring, compressor insulation, or the start relay. If you notice a smell of burning or smoke, you must immediately unplug the appliance and call a technician.
Does the amount of food affect the operating time?
An empty refrigerator cools down faster, but also heats up faster when the door is opened. A fully loaded refrigerator will hold cold better, but it will take more time and energy to initially cool a large volume of food. The optimal load is about 50-70% of the volume.