The situation when refrigeration unit buzzes without interruption is familiar to many owners of household appliances. It would seem that if the food inside the chamber remains fresh, and there is frost on the shelves, then the equipment is working properly. However, continuous operation of the compressor is an alarming signal, which, if ignored, can lead to expensive repairs or complete replacement of the device.
Constant load wears out the motor, increases energy consumption and creates discomfort due to noise. In this article, we will analyze the main reasons why refrigerator stopped pausing in operation, and determine what steps need to be taken to resolve the problem.
It is important to understand that some reasons can be eliminated yourself by simply defrosting the chamber or replacing the seal. Others require the intervention of a specialist with specialized equipment for working with refrigerants.
⚠️ Attention: If you notice that the compressor is wearing out and the temperature inside the chamber drops below normal (products freeze), immediately disconnect the device from the network to avoid damage to the thermostat or motor.
Thermostat malfunction (thermostat)
The most common reason for continuous operation of equipment is failure thermostat. It is this sensor that tells the compressor when to turn on for cooling and when to stop. If the contacts inside the thermostat “stick” in the closed position, the stop signal is never received and the motor continues to hum.
In some models, especially older ones, the thermostat may simply lose calibration. As a result, he “thinks” that the chamber is still warm, even if a block of ice has already formed there. Diagnostics of this part requires testing with a multimeter, since it is impossible to visually determine an open circuit or short circuit.
How to check the thermostat yourself?
For an initial check, you can lower the capillary tube of the thermostat into cold water with ice. If there is no click and the multimeter shows continuity (short circuit), the part is faulty and requires replacement.
Replacing the thermostat is a relatively inexpensive and quick procedure. The technician removes the old sensor, installs a new one with similar characteristics and calibrates it. After this procedure, the operating mode of the refrigerator usually is completely restored.
- 🔧 Signs of failure: the compressor hums without stopping, the temperature inside is lower than the set one.
- ❄️ Consequences: food on the top shelf may freeze, and a thick layer of snow forms on the walls.
- 💡 Solution: replacing the thermostat with a compatible model.
Refrigerant leak and problems with the system
If refrigerator does not turn off, but it freezes slightly or only in a certain place (for example, near the rear wall), there is a high probability of freon leakage. The refrigerant is the working fluid of the system, which circulates through the tubes, picking up heat. When its quantity decreases, the pressure in the system drops, and the compressor is forced to work longer to reach the set temperature.
In modern models with a system No Frost the leak may not be obvious. The unit will hum, trying to compensate for the lack of gas, but the cooling will be ineffective. Over time, the motor may overheat and burn out, since it is not designed for round-the-clock operation without breaks.
Diagnosis of a leak is carried out by eliminating and checking the pressure in the circuit. The technician uses a leak detector or soap solution to find where the pipes are damaged. After eliminating the hole, the system is evacuated and refilled with new gas.
⚠️ Attention: Filling with freon is a dangerous procedure that requires a license and special equipment. Independent attempts can lead to an explosion or fire.
Wear of the door seal
It would seem that a simple rubber band around the perimeter of the door cannot cause serious problems. However, if seal damaged, dirty or simply lost elasticity, warm air from the room constantly penetrates into the chamber. Sensors detect an increase in temperature and command the compressor to turn on again and again.
Visually, a defect in the seal may not be noticed. The rubber may look intact, but may not fit snugly in the corners or around the hinges. You can check the tightness with a simple test with a sheet of paper: clamp the sheet with the door and try to pull it out. If it is removed without resistance, it means that the seal is broken.
☑️ Checking the seal
Often the problem is solved by thoroughly washing the seal with warm water and soap to remove grease and sticky residue. If the rubber becomes dull or torn, it must be replaced. In some cases, heating with a hairdryer helps to return the material to its shape.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| Ice on food | Thermostat is faulty | Low |
| Warm inside, humming | Freon leakage | High |
| Ice build-up at the door | Damaged seal | Average |
| Noise and vibration | Compressor wear | High |
Improper installation and external factors
Sometimes the reason lies not in failure of parts, and under operating conditions. If refrigerator is too close to the wall, the radiator cannot efficiently transfer heat. Overheating causes the cooling system to work with increased load, trying to compensate for poor heat transfer.
The location next to heat sources is also affected: a radiator, an oven, or in direct sunlight. In such conditions, temperature sensors constantly record the “emergency” heating of the chamber, not allowing the motor to rest.
It is important to observe the minimum clearances specified in the manufacturer's instructions. Typically, at least 5-10 cm is required from the back wall to the wall of the room. In addition, you cannot install equipment in unheated rooms if it is not designed for this (climate class).
Check the installation level. If the floor is uneven and refrigerator is skewed, the door may not close completely, which leads to a constant flow of warm air and continuous operation of the compressor.
Malfunction of the start-up relay
Start relay is a small unit that helps the compressor start and protects it from overload. If a relay is faulty, it may produce incorrect signals or may not turn off the power circuit in a timely manner. As a result, the motor operates in the wrong mode.
Symptoms may include not only continuous operation, but also clicks, humming without starting, or frequent on-off switching. A relay is a consumable item that wears out over time, especially during power surges in the network.
The relay is replaced quickly. It is necessary to select a part with exactly the same characteristics as the original (indicated on the body). Installing a new relay often solves the problem of chaotic engine operation.
⚠️ Attention: Before replacing the relay, be sure to disconnect the refrigerator from the power supply. Working with live electrical components is life-threatening.
Problems with the control board (for electronic models)
In modern electronically controlled models, it is responsible for all processes control module. If the compressor control triac on the board burns out or a software failure occurs, the equipment may go into continuous operation.
Diagnostics of electronics is complex and requires an oscilloscope and deep knowledge of circuit design. Often, technicians recommend replacing the entire module, since repairing individual elements on the board is not economically feasible and does not guarantee durability.
If errors are on the display or indicators are blinking, this is a direct path to checking the “brains” of the refrigerator. It is not recommended to climb inside the electronic unit on your own - you can permanently damage the equipment.
Natural wear of the compressor
The most unpleasant reason is the physical wear of the compressor itself compressor. The motor life of these units is limited. Over time, the internal mechanics wear out, the valves lose their tightness, and the engine no longer produces the required pressure. To compensate for the drop in performance, it works non-stop.
Signs of wear include extraneous metallic knocking, increased vibration and a very hot motor housing. If the compressor has worked for 10-15 years, its continuous operation is its “swan song.”
Replacing a compressor is a complex and expensive repair, including soldering tubes, evacuation and refilling with freon. In older models, the cost of such repairs can be up to 70% of the price of a new refrigerator.
Frequently asked questions (FAQ)
Can the refrigerator not turn off due to the heat in the room?
Yes, if the room temperature is above +30°C, it is difficult for the refrigerator to remove heat. He will work longer, but must take breaks. If there are no pauses at all, this is already a malfunction.
How long should the compressor operate normally?
In normal mode, the operating cycle is approximately 15-20 minutes of work and 20-40 minutes of rest. The operating factor usually does not exceed 50%.
Is it dangerous to leave the refrigerator running without interruption?
Yes, it is dangerous. The compressor may overheat and burn out, and there is also a risk of the wiring catching fire or the insulation melting.
Why does a new refrigerator not turn off for a long time after being turned on?
When turned on for the first time or after a long defrosting, the refrigerator needs time (up to 24 hours) to cool the entire volume of chambers and food. This is the normal “temperature set” mode.
What to do if the refrigerator is humming, but not freezing?
Most likely, there is a freon leak or a clogged capillary tube. It is necessary to call a technician to diagnose and recharge the system.