The situation when the refrigerator does not turn offis one of the most alarming for the owner of household appliances. The constant hum of the engine not only creates discomfort in the apartment, but also signals serious malfunctions in the cooling system, which can lead to complete breakdown of the unit. Modern models, be it Indesit, LG or Bosch, are equipped with smart control systems, and if they do not send a signal to stop the compressor, it means that the required temperature in the chambers has not been reached.
Ignoring this problem is fraught overheating of the engine, melting of the wiring and, as a result, expensive repairs or complete replacement of the device. In some cases, the reason may be simple inattention of the user, but most often we are talking about technical malfunctions that require the intervention of a specialist or deep diagnostics. The critical threshold is considered to be continuous operation of the compressor for more than 24 hours, after which the probability of node failure increases exponentially.
In this article we We will analyze in detail why the refrigerator hums and does not turn off, how to distinguish a software failure from a mechanical failure, and what steps need to be taken first. Understanding the principles of operation of the thermostat and refrigerant will help you save time and money by correctly assessing the scale of the disaster.
External factors and operating errors
Before sounding the alarm and calling a technician, it is necessary to eliminate external factors that often cause this. the refrigerator does not turn off. Often the problem lies not in the breakdown of parts, but in incorrect operating conditions that prevent the system from achieving the specified temperature parameters.
The first thing you should pay attention to is the tightness of the door. If the rubber seal is worn out, dirty or deformed, warm air from the room constantly enters the chamber. The compressor is forced to work in increased mode to compensate for the heat gain, and simply does not have time to enter the rest cycle. Check the integrity of the seal around the entire perimeter.
It is also important to consider the location of the unit. If the refrigerator is standing close to the wall, in a niche or next to a catfish (battery, stove), the heat exchange of the condenser is disrupted. Rear grill it must be freely blown with air, otherwise the refrigerant will not cool to the desired temperature and the cooling cycle will not be completed. Make sure that there is a gap of at least 5-7 centimeters between the case and the wall.
- 🚪 Check whether a foreign object (dishes, bags) is preventing the refrigerator door from closing tightly.
- 🌡️ Make sure the room is not too hot: at temperatures above +30°C, some older models can work almost without interruption.
- 🧊 Do not load a large amount of warm food into the chamber, as this sharply increases the load on the system.
Another important point is the fast freezing mode. If you accidentally activate the Super Freeze or “Quick Freeze” function, the refrigerator will work until you manually turn off this mode. The corresponding indicator usually lights up on the control panel.
Malfunctions of the thermostat and sensors
One of the most common reasons for continuous operation is failure of the thermostat (thermostat). This component is responsible for monitoring the temperature inside the chambers and sends a command to turn the compressor on or off. If the contacts inside the thermostat are “stuck” in the “on” position, the motor will work endlessly, even if ice has already formed in the refrigerator.
Modern models with a system No Frost and electronic control use air temperature sensors instead of a mechanical thermostat. If such a sensor fails or gives incorrect readings (for example, it “tells” the controller that the chamber is +10°C instead of the actual -5°C), the system will continue to cool. Diagnostics of the electronic unit requires special equipment.
Symptoms of a malfunctioning thermostat are often accompanied by the absence of a characteristic click when the desired temperature is reached. In mechanical models, you can try to carefully turn the regulator knob: if the click is not heard and the motor does not stop, the part likely requires replacement.
⚠️ Attention: Replacing the thermostat yourself requires skills in working with electrical circuits. Before dismantling, be sure to unplug the refrigerator, as there is a risk of a short circuit.
It is also worth checking the capillary tube of the thermostat. If it is incorrectly installed in the chamber or moved away from the evaporator, the sensor does not read the real air temperature, which leads to incorrect operation of the entire system.
How to check a mechanical thermostat with a multimeter?
To check, remove the thermostat, set the multimeter to dial mode and connect the probes to the contacts. At room temperature the chain should ring. If you place the sensing element in the cold (for example, in the freezer for 15 minutes), the circuit should break. If this does not happen, the thermostat is faulty.
Refrigerant leak and problems with the compressor
If no external causes are found and the thermostat is working, the problem may lie in a leak in the refrigeration circuit. Freon leak is a serious malfunction in which the refrigerant becomes insufficient for efficient heat removal. The compressor works non-stop, trying to compensate for the lack of pressure, but the temperature in the chambers does not drop to normal.
Signs of a leak are often swelling on the back wall (where the condenser is sealed) or oily spots where the tubes are damaged. In some cases, the leak occurs in the foamed part of the housing, which makes repair economically impractical. Only a technician with a leak detector can determine the exact location of gas loss.
The other extreme is wear of the compressor itself. Over time, the piston group wears out and the engine loses its ability to create the necessary pressure in the system. It hums and vibrates, but does not “pump” freon with the required efficiency. As a result, the refrigerator operates around the clock, but does not cool well.
To diagnose the compressor, the current in the windings and the pressure at the outlet are measured. If the current consumption is significantly lower than the nominal one, and the pressure does not increase, this is a sure sign of a loss of motor performance.
Clogged capillary tubes
Another technical reason why the refrigerator does not turn off is clogging of the capillary tube. This is a thin element of the system through which the refrigerant passes from a high pressure zone to a low pressure zone. Over time, oil oxidation products or moisture may accumulate in the system, which turns into an ice plug.
When clogged, the circulation of freon is disrupted: the compressor tries to push gas, working at the limit, but cooling does not occur. A characteristic sign of such a malfunction is that the condenser (grid at the back) remains cold or warm only at the very beginning, and the filter drier may become covered with frost.
Removing the blockage requires purging the system with nitrogen at high pressure and replacing the filter drier. It is impossible to carry out this procedure on your own without a compressor and a vacuum gauge, since complete sealing and proper charging with refrigerant are required.
It is important to understand that ignoring the blockage leads to rapid burnout of the compressor due to operation in the “dry running” mode or overload. Therefore, if you suspect this problem, you should immediately stop using the unit.
Failures in the defrosting system (No Frost)
In refrigerators with a system No Frost continuous operation of the compressor is often associated with a malfunction of the automatic defrosting system. If the evaporator becomes overgrown with a “coat” of ice, the air flow is blocked and the cold does not enter the chamber. The temperature sensor does not detect cooling, and the motor continues to work.
The main culprits in this situation:
- ❄️ Defrost heating element - it is burned out and does not heat, which is why the ice does not melt.
- 🕰️ Timer or control module - does not give a command to turn on the defrost mode.
- 🌡️ Defrost sensor - incorrectly reads the evaporator temperature.
Diagnose the problem You can defrost the refrigerator manually within 24 hours. If after turning it on it works normally, but after 1-2 weeks the situation repeats (the ice freezes again and stops cooling), then the defrosting system is not functioning.
In models with electronic control, an error code may light up on the display, indicating a problem with the evaporator temperature sensors. The decoding of the codes for your model (Samsung, LG, Indesit) can be found in the technical documentation.
☑️ Diagnostics of the No Frost system
Diagnostic table: Symptoms and probable causes
To simplify troubleshooting, use the following table. It will help to compare visible signs with possible breakdowns.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The refrigerator hums, but does not get cold | Freon leak, blockage, compressor breakdown | Call a technician to find the leak |
| The engine is hot, running non-stop | The thermostat is faulty, the condenser is dirty | Check the thermostat, clean the grille at the back |
| There is ice in the chamber, the motor does not turn off | Failure of the defrost system (No Frost), loose door | Defreeze, check the heating element and seal |
| A knock is heard, vibration, long operation | Wear of compressor suspension, incorrect installation | Align legs, check shock absorbers |
| Alarm indicator flashing, non-stop operation | Electronic module faulty or sensor | Diagnostics of electronics by a specialist |
Please note that an accurate diagnosis can only be made by a qualified specialist after an instrumental examination. Self-diagnosis only helps to determine the search vector for the problem.
When you need to call a technician
There are a number of situations when attempts at self-repair can lead to permanent equipment failure. If you have checked the seals, defrosted the unit, made sure that the socket is working, but the refrigerator continues to work without shutting downmost likely the problem is of a technical nature.
It is especially dangerous to ignore the smell of burning or a humming sound followed by clicks. This may indicate an interturn short circuit in the motor windings or a jammed compressor. Further connection to the network may lead to a fire.
⚠️ Attention: Opening the sealed circuit (tubes with freon) on your own is strictly prohibited. This requires a license, special equipment and knowledge. An attempt to “top up” the gas without eliminating the leak will only temporarily solve the problem.
Professional help is also necessary when it comes to replacing the electronic control module. Incorrect soldering or installation of an unsuitable board can damage other components of the refrigerator.
Frequently asked questions (FAQ)
Can the refrigerator work without stopping in summer?
In very hot weather (above +30-32°C), the compressor operating time increases, but shutdown cycles should still be present. If the refrigerator runs for days without a break, even in the summer, this is a malfunction (leakage, thermostat), and not the norm.
How long should the refrigerator rest between starts?
Normally, the operation cycle is approximately 15-20 minutes, and the rest cycle is 10-15 minutes. The work/rest ratio is approximately 50/50 or 40/60. If the refrigerator turns on immediately after being turned off or does not turn off for hours, this is a reason for diagnosis.
Why does a new refrigerator work longer than usual?
When turned on for the first time or after complete defrosting, the refrigerator requires time (from 3 to 12 hours) to cool the entire volume of chambers and food to the set temperature. During this period he can work without interruption. This is normal.
Does the amount of food affect the operating time?
Yes, a full refrigerator keeps the cold longer, but it also takes longer to cool initially. An empty refrigerator reaches temperature faster, but turns on more often. However, in no case should it work around the clock without stopping.
Is it dangerous to leave a refrigerator running without stopping?
Yes, it is dangerous. The compressor is not designed to operate 24/7. It may overheat, resulting in insulation melting, short circuit and fire. In addition, the engine resource will be exhausted in a few days instead of the required 10 years.