The situation when the refrigerator operates around the clock without entering rest mode frightens many owners. The hum of the compressor, which usually subsides 15–20 minutes after switching on, becomes a constant background in the apartment. This is not just discomfort: continuous operation of the motor leads to overheating, rapid wear of parts and, as a result, to expensive major repairs or replacement of the unit.
Understanding this why the refrigerator does not turn offrequires analysis of several factors. This can be either a trivial error in operation or a serious technical breakdown of the thermoregulation system or the tightness of the circuit. In this article, we will analyze diagnostic algorithms in detail so that you can determine the nature of the malfunction and make the right decision on further actions.
The first thing to do is not to panic, but also not to ignore the problem. If the equipment has been working in intensive mode for several hours, this is a signal that the set temperature inside the chambers has not been achieved. The control system “thinks” that it is still warm inside and forces the compressor to pump refrigerant without stopping.
It is important to distinguish between normal operation in extreme conditions and pathology. For example, if you just loaded an empty refrigerator with 20 kilograms of warm meat, it will last a long time. But if the non-stop mode persists with a full load and a stable room temperature, then there is a failure in the control or heat exchange circuit.
External factors and operating errors
Before looking for a breakdown inside the unit, it is worth eliminating the influence of the external environment. Often the reason lies in violation of installation rules or incorrect user actions. Thermostat is a sensor that “tells” the motor when to stop. If the conditions around the refrigerator do not allow it to cool or the sensor receives false signals, the shutdown will not occur.
One of the most common reasons is incorrect installation. If the refrigerator is placed close to the wall, in a niche without gaps, or next to a hot stove, heat exchange is disrupted. The compressor overheats, and the heat that should be lost through the radiator grille at the rear is returned back to the system. As a result, freon does not have time to cool down, and the cooling cycle does not complete.
It is also worth checking the tightness of the door. If sealing rubber is worn out, dirty or deformed, warm air from the room constantly enters the chamber. The temperature sensor detects the increase in degrees and gives the command to the motor to continue working. You can check the tightness using a simple sheet of paper: clamp it with the door and try to pull it out. If the sheet is removed easily without resistance, the seal is broken.
Another important point is the room temperature. Most household refrigerators are designed to operate in climate class SN or N, that is, at air temperatures from +10°C to +32°C. If the room is +35°C or higher (for example, in the summer in a kitchen without air conditioning), the standard power of the compressor may not cope with the heat influx, and it will work continuously, trying to somehow cool the chambers.
Malfunctions of the thermoregulation system
If external conditions are normal, the problem most likely lies in the “brains” of the refrigerator - the control system temperature. It is she who decides when to turn on and when to turn off the compressor. In older models, a mechanical one is responsible for this; in modern models, an electronic control module and temperature sensors are responsible. thermostat, in modern ones - an electronic control module and temperature sensors.
In mechanical models, the thermostat is a device with a bellows filled with gas or liquid. As the chamber cools, the gas compresses, the contacts open, and current stops flowing to the motor. If this unit fails (the contacts are stuck or the bellows is depressurized), the circuit does not break. The compressor hums without interruption, as it simply does not receive the “Stop” signal.
⚠️ Attention: Replacing the thermostat requires precise adjustment. If you install the wrong model or incorrectly adjust the length of the capillary tube, the refrigerator may either not turn on at all or freeze the food to the point of stone.
In units with a system No Frost and electronic control, the role of a thermostat is performed by thermistors (temperature sensors). They transmit data to the main controller. If the sensor “lies” and shows that the chamber is +10°C instead of the real +4°C, the control module will keep the compressor on. Often such sensors fail due to voltage surges or natural aging.
How to check a thermostat with a multimeter?
To check a mechanical thermostat, it must be dismantled. When warm, the contacts should “ring” (conduct current). If you place the sensor in the cold (for example, in the freezer) for 15 minutes, the contacts should open. If this does not happen, the part is faulty.
Problems with tightness and refrigerant leakage
One of the most serious and common reasons for continuous operation is a leak in the refrigeration circuit. The system circulates freon (refrigerant), which takes heat from the chambers and releases it to the environment. If a microcrack forms in the tubes or evaporator, the gas begins to evaporate.
When freon becomes less than normal, it is not enough for a full cooling cycle. The pressure in the system drops, the evaporator temperature does not drop to the required values. The sensor detects “heat” and does not give a command to turn off. The compressor works hard, trying to compensate for the lack of refrigerant, but the desired cold never comes.
Often the leak is accompanied by additional signs:
- 🔊 The compressor works very quietly or, conversely, with a strong metallic clang.
- ❄️ Freezer the chamber is working, but the refrigerator compartment is warm (or vice versa).
- 💧 Oil appears under the refrigerator or on the tubes at the back (oil comes out along with the gas).
- 🌡️ The condenser (grid at the back) heats up unevenly or remains cold.
Find a place on your own Leaks are difficult because the gas is colorless and odorless. Craftsmen use leak detectors or the method of washing joints. Eliminating such a problem requires not only finding the hole, but also evacuation of the system and filling with new freon strictly by weight.
Clogged capillary tube and compressor malfunction
Another technical reason is clogged capillary tube. This is a thin copper channel in which throttling (sharp expansion) of the refrigerant occurs. If there is moisture in the system, it can freeze at the narrowest point of the tube, forming an ice plug. Freon stops circulating, pressure rises, but there is no cold. The compressor hums, trying to push gas, but to no avail.
Sometimes the problem lies in the very heart of the refrigerator - the compressor. Over time, the mechanism wears out: the piston group loses compression, the valves burn out. The motor hums, the shaft rotates, but does not create the necessary pressure for freon circulation. In this case, they say that the compressor “does not hold pressure.”
To diagnose the condition of the compressor, technicians use a pressure gauge station. It connects to the service fitting and shows the actual discharge and suction pressure. If the arrows do not rise to operating values when the engine is running, the diagnosis is obvious.
Specifics of operation of refrigerators with No Frost
In refrigerators with the system No Frost another layer of complexity is added. Here fans provide air circulation, and the heating element (heating element) is responsible for defrosting the evaporator. If the defrosting system fails, the evaporator becomes overgrown with a “coat” of ice. Heating element (heating element). If the defrost system fails, the evaporator becomes covered with a “coat” of ice.
Ice blocks the air channels. The fan moves air, but it cannot pass through the frozen evaporator and cool the chambers. The temperature sensor in the refrigerator compartment sees that there is no cold and keeps the compressor on. At the same time, it may be colder in the freezer than necessary, and warm in the refrigerator compartment.
The main elements of the defrost system that can fail:
- 🔥 Defrost heating element (the spiral burns out).
- 🕰️ Defrost timer (mechanical or electronic, does not switch modes).
- 🌡️ Defrost sensor (does not allow the heating element to turn on).
- 💨 Fan (stops due to ice or breakdown).
Often in such cases, completely defrosting the refrigerator in the off state for at least 24 hours helps. If after turning it on it works normally, and a week later the situation repeats, it means that one of the elements of the defrost system is faulty and requires replacement.
Diagnostics and table of symptoms
To make it easier for you to navigate a possible breakdown, we have compiled a summary table of symptoms. It will help narrow down the search for the problem before calling a specialist.
| Symptom | Probable cause | Difficulty of repair | Can I fix it myself |
|---|---|---|---|
| The refrigerator is humming, It’s warm inside, the condenser is cold | Freon leak or blockage | High | No, you need a master |
| The motor is hot, does not turn off, but there is cold | Faulty thermostat | Average | Yes, if you have the skills |
| The sound of boiling water is heard, the cold is weak | Air lock or lack of freon | High | No |
| The compressor turns on for 10 seconds and clicks | Start relay or compressor wedge | Medium/High | Partially (relay) |
| Ice in the freezer, warm in the refrigerator compartment | Clogging or problem with No Frost | Medium | Try defrosting |
If you find that the problem is related to the electrical part (relay, thermostat), and have minimal experience, replace the part. However, any manipulations with a sealed circuit (pipes, freon) require special equipment: a vacuum pump, pressure gauges and scales.
☑️ Actions before calling a specialist
When necessary urgent call to a technician
There are situations where attempts at self-repair can only aggravate the situation or lead to fire hazards. If you hear a burning smell, see sparking or feel strong heating of the wires, immediately unplug the device.
Also, do not hesitate if the refrigerator has stopped freezing and the compressor is running around the clock. Long-term dry operation (without freon, which is also a coolant for the motor windings) leads to rapid combustion of the compressor. Replacing a motor costs much more than timely refilling with freon.
⚠️ Attention: Modern inverter compressors are very sensitive to voltage surges and diagnostic errors. An attempt to “unwedge” such a motor using traditional methods is almost guaranteed to disable the electronic control board.
Remember that a professional technician has access to original spare parts and knows the technical nuances of specific models Indesit, Bosch, LG or Atlant. He will be able to accurately determine whether it is necessary to change the entire unit or whether it is enough to replace one small part.
Why is it better not to repair an old refrigerator?
If your refrigerator is more than 10-12 years old and the compressor has burned out, it is often more economically feasible to buy new equipment. The cost of a new motor, work to replace it and refill with freon can be up to 70% of the price of a new budget refrigerator.
Prevention and operating rules
To extend the life of the refrigerator and avoid situations where it cannot turn off, follow simple rules of prevention. Regularly clean the rear of the condenser grille to remove dust. A 1-2 mm layer of dust acts as a heat insulator, interfering with heat transfer, which makes the compressor work longer.
Do not place hot foods in the chamber. This creates a colossal load on the system. Also monitor the amount of food: if the refrigerator compartment is crowded, air does not circulate, and the sensors may not work correctly.
Check the condition of the seal every six months. Wipe it with a soft cloth and remove crumbs. If the rubber band has become hard, you can treat it with a special silicone spray to restore elasticity.
Following these recommendations will help you avoid costly repairs and ensure safety of your products. If a problem has already arisen, correct diagnosis will help you quickly return the equipment to operation.
Why does the refrigerator work constantly after defrosting?
If after complete defrosting (24 hours) the refrigerator continues to work without stopping, this indicates a technical malfunction: a freon leak, a broken thermostat, or a blockage. Ice was only a symptom, not a cause.
Can the refrigerator not turn off due to heat?
Yes, if the temperature in the room exceeds +32°C (for most models), the refrigerator will work non-stop, since its power is not enough to overcome the heat inflow from the outside.
Dangerous is it possible if the compressor runs for 24 hours?
Short-term (up to 12 hours when loading warm products) is acceptable. Long-term operation leads to overheating of the windings, destruction of the oil and eventual jamming of the motor. This is dangerous due to fire and costly repairs.
How to understand that the thermostat has burned out?
If when you turn the thermostat knob to the "0" (off) position the compressor does not stop, and when turned on to the minimum mode it does immediately, most likely the thermostat contacts are stuck in the closed position.
Do you need to turn off the refrigerator if it does not turn off on its own?
Yes, if you see that it has been running for more than 12 hours without a break, forcefully disconnect it from the network for diagnostics. Further work may permanently damage the compressor.