The situation when the refrigerator hums incessantly often takes you by surprise. You notice that the counter is spinning faster than usual, and the unit does not go into rest mode. This is a sure sign that the cooling system is trying to compensate for the loss of cold or is coping with excessive load. Ignoring this symptom can lead to overheating of the compressor and expensive repairs.
Modern models, be it LG, Bosch or Indesit, are equipped with smart electronics that should regulate operating cycles. However, even the most advanced technology cannot ignore the physical laws of thermodynamics. If the heat flow into the chamber is too great or the refrigerant has left the circuit, the motor will wear out.
In this article we will analyze in detail the main reasons why the refrigerator works without interruption, and we will tell you what steps you can take on your own, and when it is better to call a technician. Understanding the principles of operation will help you save your budget and keep your food fresh.
Violation of the tightness of chambers: seals and doors
The most commonplace, but common reason is a violation of the tightness of the refrigerator or freezer chambers. If the rubber seal on the door is worn out, dirty, or simply does not fit tightly, warm air from the room constantly penetrates inside. Sensors detect an increase in temperature and forcefully turn on the compressor, which cannot turn off because it does not reach the set parameters.
Check the condition seals along the entire perimeter. There should be no cracks, creases or sticky residue on them. Sometimes the problem can be solved by simply washing the rubber with warm water and soap to remove any grease that is preventing a tight seal. Also make sure that the door is not warped due to improper installation or overweight.
For a quick diagnosis, use a simple test with paper. Clamp the piece of paper with the refrigerator door. If it falls out easily or is pulled out without resistance, it means the seal is broken. In places where the paper does not hold well, heat leakage most likely occurs.
- 🧼 Thoroughly clean the seal from grease and crumbs.
- 🔥 Use a hair dryer to smooth out wrinkles on the rubber (carefully!).
- 🔧 Check the door hinges for sagging.
If the rubber has become hard and lost elasticity, it will have to be replaced. This is a consumable material that ages over time in any equipment, be it Samsung or Atlant.
⚠️ Attention: Do not ignore the gaps in the seal. Constant operation of the compressor in this mode can lead to its combustion in a matter of weeks due to the lack of rest cycles.
Problems with the thermostat and temperature sensors
The “brain” of the refrigerator is the thermostat or electronic control module. It is these elements that give the command to turn the engine on and off. If the thermostat has failed and is stuck in the “on” position, the compressor will hum continuously. In older models with mechanical control, this is a frequent breakdown.
In modern systems No Frost electronic sensors (thermistors) monitor the temperature. If one of them transmits incorrect data that the chamber is too warm, the controller will not turn off the motor. The error may be caused by oxidation of the contacts, a broken wire, or failure of the sensor itself.
Diagnostics of the electronic unit requires special knowledge and equipment. You can only check the mechanical thermostat yourself. To do this, you need to test it with a multimeter at different temperatures. If the contacts do not open when heated, the part needs to be replaced.
Refrigerant leakage: a hidden threat to the system
Refrigerant (freon) is a working fluid that circulates through tubes and transfers heat. If a microcrack has formed in the circuit, the gas gradually evaporates. Its quantity becomes insufficient for effective cooling. The compressor tries to compensate for the lack of cold and works non-stop, trying to gain temperature.
The main sign of a leak is weak cold or its complete absence, while the rear grille of the refrigerator remains warm or barely warm. Normally it should be hot. Oily spots may also appear where the tube is damaged, since freon circulates along with the compressor oil.
It is impossible to find and repair the leak on your own. Professional equipment is required to locate the damage, solder and evacuate the system. After the repair, you will need to refill with new freon strictly according to the rate indicated on the nameplate.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The refrigerator hums, but does not freeze | Freon leak | Call a technician to find a leak |
| Dirt on the back wall | Oil stain from freon | Checking the integrity of the circuit |
| The compressor is hot | Overload due to lack of gas | Urgent shutdown and repair |
| Frost only at the entrance to the tubes | Partial loss of refrigerant | Diagnostics of pressure in the system |
⚠️ Attention: Operating a refrigerator with a freon leak is dangerous. The compressor, operating at idle speed without proper cooling of the returning gas, can burn out, which will increase the cost of repairs significantly.
Compressor malfunction: when the motor is tired
The compressor is the heart of the refrigerator. If it runs continuously, this may indicate an internal problem. Interturn short circuit of windings or wear of mechanical parts lead to the fact that the motor does not develop the required power, but consumes current and hums.
Often owners confuse cause and effect. The compressor may work non-stop not because it itself has broken down, but because it cannot complete the task due to the problems described above (leakage, bad seal). However, if all systems are working properly, and the motor does not turn off, the problem is there.
A sign of a compressor malfunction may be a specific knocking, humming, change in the tone of the operating sound, or strong heating of the housing. In some cases, the circuit breaker in the electrical panel may knock out.
- 🔊 Listen: is there a metallic knock inside the motor.
- 🌡️ Check the temperature of the compressor housing (be careful, it can be very hot).
- ⚡ Measure the starting current (only for specialists).
Replacing a compressor is a complex technical process that requires resoldering pipes and refilling with freon. It is almost impossible to perform this operation independently without experience and tools.
Clogged capillary tube and filter drier
There is a bottleneck in the freon circulation system - the capillary tube. Its diameter is extremely small, and it is there that a sharp drop in pressure occurs. Over time, a blockage may form in the system (oil oxidation products, moisture, dirt). Freon cannot circulate normally, and cooling efficiency drops.
Symptoms of a blockage are similar to a leak: the refrigerator runs constantly, but there is not enough cold. In this case, the condenser (grid at the back) may be only partially hot or cold. The filter drier, which is located in front of the capillary, can also become clogged.
To eliminate this malfunction, the system must be purged with nitrogen under high pressure, replaced with a filter drier, and vacuuming. This is a standard procedure for any opening of the circuit.
The influence of external factors and operating errors
Sometimes the equipment is working properly, but operating conditions do not allow it to return to normal operation. High room temperatures (for example, +30°C in the kitchen in summer) cause the refrigerator to work longer to maintain the cold inside. This is normal for older models, but modern inverter compressors should do a better job.
Put a hot pan in the refrigerator? The sensors will detect a temperature jump, and the motor will operate at maximum until the volume cools down. Also, frequently opening the door or loading a large volume of food at room temperature causes prolonged operation without interruption.
Check whether the refrigerator is not located too close to the wall or radiator. For normal operation, the heat exchanger needs air flow. If the gap is less than 5-10 cm, heat is not dissipated and efficiency decreases.
You turned on the function Super Freeze (Super Freeze) and forgot to turn it off? In this mode, the refrigerator freezes without stopping forcibly. Check the control panel.
⚠️ Attention: Technical characteristics of refrigerators are designed to operate in a certain climate class. If the nameplate indicates class
SN(subnormal, up to +32°C), and your kitchen is +35°C, constant operation of the compressor is an expected reaction that reduces the life of the equipment.
Frequently asked questions (FAQ)
How long should a refrigerator operate normally?
In normal mode, the refrigerator operates cyclically. The working time is usually from 20 to 40 minutes, followed by a pause (rest) lasting from 15 to 30 minutes. The work factor (work time / total time) is normally around 0.3–0.5 (30-50%). If the refrigerator runs for 2 hours without a break, this is an alarming signal.
Is it dangerous if the refrigerator hums all night?
Yes, it is dangerous. Long-term operation without stopping leads to overheating of the compressor windings. The motor is designed for cyclic mode, where it cools down during a pause. A constant load can lead to melting of the insulation, a short circuit and complete failure of the unit.
Could the defrosting mode be the cause?
The defrosting (defrost) mode itself usually turns off the compressor, since the heating element turns on. However, if the defrost sensor or timer is faulty, the system may become stuck in a cycle, and once the defrost is complete, the compressor will cycle through a long temperature recovery cycle. But defrosting directly does not make the motor hum continuously.
What to do first if the refrigerator does not turn off?
1. Check the tightness of the door closure and the cleanliness of the seal.
2. Make sure that the super freeze mode is not turned on.
3. Check if there is a heat source nearby.
4. If visually everything is in order, unplug the device for 2-3 hours to defrost. If after switching on the problem repeats, you need a technician.
Is it true that a new refrigerator should work for a long time?
When turned on for the first time, a new refrigerator can work without interruption for up to 24 hours, gaining its original temperature. This is fine. But if it does not turn off already the second day after purchase, it is defective or damaged during transportation.