The situation when the refrigerator does not hum ceasing, is familiar to many owners of household appliances. Instead of the usual on and off cycle, compressor works non-stop, which leads to excessive energy consumption and overheating of the unit. This can signal either a banal violation of operating rules or a serious breakdown of internal components.
This symptom cannot be ignored, since long-term wear and tear can permanently damage an expensive engine. In this article, we will look at the main reasons why motor does not turn off and determine what steps need to be taken to fix the problem.
Before calling a technician or disassembling the back wall, it is important to understand the physics of the cooling process. The refrigerator must reach the set temperature, after which the thermostat issues a command to stop. If this does not happen, it means that the system cannot achieve the target values or the sensor is not reading the data correctly.
Seal failure and problems with the seal
The most common and easily eliminated reason for continuous operation is a violation of the chamber seal. If warm air from the room gets into the gaps between the door and the body, it thermostat records an increase in temperature and forces the motor to work constantly. Often the culprit is a worn or dirty thermostat seal. Carefully inspect the rubber gasket around the perimeter of the door. There should be no cracks, creases or sticky residue that would interfere with a tight fit. Even a microscopic gap causes the cold to escape and heat to enter, forcing the equipment to work in increased mode. seal.
Carefully inspect the rubber gasket around the perimeter of the door. There should be no cracks, creases or sticky residue that would interfere with a tight fit. Even a microscopic gap causes the cold to escape and heat to enter, forcing the equipment to work in increased mode.
Check how tightly the door closes. To do this, you can use a simple test with a sheet of paper: hold the sheet with a door and try to pull it out. If the paper comes out freely without resistance, the seal is broken.
You should also pay attention to the door hinges. Over time, they can become loose and cause the door to warp, creating a gap at the top or bottom. Adjusting the hinges often solves the problem without replacing parts.
Incorrect installation of the thermostat
Sometimes the reason lies in the user’s banal inattention. If the thermostat knob is set to the maximum value (usually numbers 6, 7 or mode Super Freeze), the refrigerator will strive to reach extremely low temperatures. In hot weather or when fully loaded with products, it may simply not cope with the task, working without interruption.
The optimal mode for most models is considered to be the handle position at 3 or 4. In this range, a balance is provided between high-quality cooling and energy efficiency. Try reducing the cooling power and monitoring the reaction of the equipment for several hours.
⚠️ Attention: Do not set the thermostat to maximum during normal operation. This creates excess load on the compressor and can lead to its premature failure.
External factors should also be taken into account. If the refrigerator is located next to a radiator, stove, or in direct sunlight, it is more difficult for the system to release heat. In such conditions, even standard settings may not be sufficient to stop the motor.
Malfunctions of the thermostat and temperature sensors
If the regulator knob is positioned correctly and the seal is intact, it has probably failed itself thermostat. This device is responsible for turning the compressor on and off depending on the temperature inside the chamber. If damaged, the contacts may “stick” in the “on” position, and the motor will run endlessly.
In modern models with a system No Frost and electronic control, instead of a mechanical thermostat, air sensors (thermistors) are used. They can transmit incorrect data to the control module, reporting that the chamber is warm, although in fact the temperature is already below normal.
Diagnostics of these elements requires special instruments, such as a multimeter. At home, you can try to gently knock on the thermostat body (if it is mechanical), sometimes this helps to unblock stuck contacts, but this is only a temporary measure.
How to check a thermostat with a multimeter?
To check, you need to remove the thermostat, immerse its sensitive tube in water with ice and ring the contacts. If the circuit does not open during cooling, the part is faulty and requires replacement.
Replacing a thermostat or sensor is a procedure that requires disassembling the refrigerator. If you do not have the skills to work with electrical appliances, it is better to entrust this to specialists, as there is a risk of damaging other components.
Problems with refrigerant and freon leakage
One of the most serious reasons for continuous operation is leakage freon. The refrigerant circulates through a system of tubes, taking heat from the chambers. If its quantity decreases due to microcracks in the circuit or corrosion, the cooling efficiency decreases. Trying to compensate for the lack of cold, the compressor works without stopping.
Symptoms of a leak are often:
- 🔥 Strong heating of the side walls of the refrigerator or condenser at the back.
- ❄️ Weak cooling of food or complete absence of cold when the engine is running.
- 🔊 Change in the sound of the compressor (may become quieter or louder).
- 💧 The appearance of swelling on the tubes or oily spots near the compressor.
Fix the leak yourself and fill the system with freon impossible. Special equipment is required to evacuate the system and accurately charge the refrigerant. In addition, it is necessary to find and solder the leak, which often requires welding.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The engine is humming, there is no cold | Freon leak | High (needs a technician) |
| The refrigerator turns off, but rarely | The condenser is dirty | Low (cleaning) |
| Compressor is hot, clicking | Faulty start relay | Medium (part replacement) |
| Ice on the back wall | Faulty defrost sensor | Average (diagnosis) |
Condenser contamination and heat transfer failure
Condenser (black grille rear or built-in tubes in the side walls) is responsible for heat transfer to the environment. If it is covered with a thick layer of dust, pet hair or fluff, heat transfer is impaired. Freon cannot cool down and turn into a liquid state, so the pressure in the system increases and the motor does not turn off.
Regular cleaning of the condenser is a mandatory maintenance procedure. It is recommended to carry it out at least once a year, and if you have animals - every 6 months.
For cleaning, use a vacuum cleaner with a soft attachment or a dry soft brush. Do not wet the grill with water if it is electric or has wiring nearby to avoid short circuiting. Also, ensure a gap between the back wall of the refrigerator and the wall of the room of at least 10 cm for free air circulation.
⚠️ Attention: Do not use sharp objects (knives, screwdrivers) to remove dense lumps of dust from the condenser. Damage to the tubes will lead to an immediate leak of freon.
Wear of the compressor and start relay
Yourself compressor is the heart of the refrigerator. Over time, its mechanical parts wear out, compression is lost, and it ceases to produce the necessary pressure. In an attempt to achieve the specified parameters, it begins to work longer and more often, up to continuous mode.
Another important element is the start-up relay. It starts the motor and protects it from overloads. If the relay is faulty, it may not turn off the motor winding or not start the second phase, which is why the hum continues, but cooling does not occur.
☑️ Diagnostics before calling a technician
If you hear that the engine is getting very hot, making a metallic clang or humming, but does not start (you can only hear click), most likely the problem is in the compressor-relay connection. In this case, operating the refrigerator is dangerous and can lead to a fire.
Failures in the electronic control module
In modern refrigerator models, all processes are controlled electronically control module. If it malfunctions (for example, due to a power surge), it can send incorrect commands to the compressor. The motor receives the “run” signal constantly, ignoring the temperature sensor readings.
Rebooting the system often helps. To do this, you need to disconnect the refrigerator from the power supply for 15–20 minutes. This will allow you to reset errors in the controller's memory.
If the situation repeats after switching on, it is likely that the module will need to be re-flashed or burnt-out elements on the board must be replaced. Self-repair of electronics without a diagram and experience is highly not recommended, since a mistake can cost more than a new board.
Why are voltage surges dangerous for electronics?
Sudden voltage drops can damage the sensitive microcircuits of the control module, which will lead to incorrect operation of all refrigerator systems, including the compressor and fans.
The influence of external factors and the Super Freeze mode
Do not forget about the quick freezing function. If you accidentally activate the mode Super Freeze (usually indicated by a snowflake or a button with the appropriate name), the refrigerator will work without interruption for up to 24–72 hours until the function is turned off automatically or manually. Check the control panel.
The room temperature also affects operation. If the room is hot (above +30°C), a standard household refrigerator may not have enough power to stop the compressor, since the temperature difference is too great.
It is important to consider that technical characteristics and operating algorithms may differ depending on the model and year of manufacture. Always check the manufacturer's instructions for your specific equipment to understand the specifics of its operation.
⚠️ Attention: Long-term operation of the refrigerator in non-stop mode (more than 24 hours) without breaks is dangerous due to overheating of the compressor windings and can lead to its complete combustion.
Frequently asked questions (FAQ)
How long should the refrigerator operate after turning on?
Usually the first cooling cycle after defrosting or long-term inactivity takes from 2 to 12 hours, depending on the volume of the chambers and the number of products. After reaching temperature, the motor should turn off.
Is it dangerous to leave a refrigerator that does not turn off overnight?
Yes, it is dangerous. In addition to the risk of failure of an expensive compressor, there is a possibility of overheating of the wiring and a fire. It is better to turn off the device until the reasons are determined.
Can the refrigerator not turn off due to a large amount of food?
Yes, if you loaded a lot of warm food at once, the refrigerator will take longer to cool. However, after a few hours the cycle should normalize.
Why does the new refrigerator work without interruption?
When turned on for the first time, the new refrigerator takes time (up to 24 hours) to reach operating mode. If after a day of operation it does not turn off and does not cool, this is a defect or damage during transportation.