The situation when the refrigerator compressor hums without interruption, and the set temperature inside the chamber is not reached, is critical for the safety of food. Constant operation of the motor indicates that the system cannot reach the cold maintenance mode, which inevitably leads to overheating of the components and a sharp increase in electricity bills. The owner needs to quickly understand whether the problem is technical in nature or caused by external factors.
First of all, it is worth assessing exactly when the problem arose: immediately after loading a large volume of warm products or suddenly during normal operation. If you have just placed hot pots or a large amount of defrosted meat in the chambers, the unit will work in enhanced mode until the contents have cooled to the specified parameters. However, if the equipment hums for days even with minimal load, this is a direct signal of a malfunction of one of the components of the cooling system.
Modern models, such as Indesit, Atlant or Beko, are equipped with complex electronics that can block the compressor from turning off in the event of a refrigerant leak or sensor failure. Ignoring this symptom often leads to complete failure of an expensive compressor, the repair or replacement of which can cost up to 70% of the price of a new device. Therefore, it is important to act consistently, eliminating simple causes before calling a specialist.
The influence of the operating mode and quality of the seal
The most commonplace, but often overlooked reason is a violation of the chamber’s tightness. If the rubber door seal is worn out, cracked, or simply contaminated with sticky food debris, warm air from the room constantly enters the chamber. The temperature sensor detects an increase in degrees and sends a signal to the control unit to turn on the compressor. The cycle closes: the motor tries to cool the incoming heat, but cannot reach the target temperature due to the loose fit of the sash.
Carefully inspect the seal around the entire perimeter. There should be no creases, tears or mold on it. Pay special attention to the corners where the rubber often pulls away from the body. Check the seal using a simple test with a sheet of paper: press a sheet of paper between the body and the seal, close the door and try to pull the paper out. If it is removed without the slightest resistance, it means that the tightness is broken.
⚠️ Attention: When trying to level a deformed seal using a hair dryer, do not overheat the rubber above 60-70 degrees, otherwise it will lose elasticity and begin to crumble.
It is also worth checking that Is the door itself warped? Over time, the hinges can weaken under the weight of the food, and the sash warps, forming a gap at the bottom or side. Adjusting the hinges usually takes a few minutes and requires only a screwdriver, but returns the necessary tightness to the equipment. If the rubber is intact and the hinges are in order, the reason may lie in the settings or deeper technical problems.
Operation errors and temperature settings
Often users themselves create the conditions for continuous operation of the equipment by activating modes intended for emergency situations. For example, the Super Freeze or Quick Freeze function forces the compressor to run for 24-48 hours to quickly freeze fresh food. If you forget to disable this option, the refrigerator will work for wear until the timer is reset or the user intervenes with the settings.
Check the control panel: is the alarm indicator or snowflake icon on? In some models, such as LG or Samsung, a failure in the electronic module can “hang” the program, and the equipment will think that the accelerated freezing mode is active. Resetting the settings to factory settings through the menu or disconnecting the device from the network for 15-20 minutes often solves the problem of software freezing.
Another factor is the location of the equipment. If the refrigerator is standing close to the wall, in a niche or next to a heat source (battery, stove), heat exchange is disrupted. The condenser (grid at the back) does not have time to cool down, and the cooling efficiency drops. The compressor is forced to work longer to compensate for the lack of cooling capacity. The minimum distance to the walls should be 5-10 cm for free air circulation.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” that decides when to turn the motor on and off. In mechanical models, this is a simple capsule of gas or liquid that expands when heated and opens the contacts. If the thermostat is “stuck” in the “On” position or its capillary tube has lost its seal, the circuit will not break and the compressor will hum endlessly.
In modern units with a system No Frost and electronic control, the role of a thermostat is performed by temperature sensors (thermistors). They are resistors that change resistance depending on temperature. If the sensor “lies” and shows the control unit that the chamber is +10°C instead of the required +4°C, the electronics will keep the compressor on. Replacing the sensor is a simple procedure, but requires testing with a multimeter for diagnostics.
How to check a thermostat with a multimeter?
To check a mechanical thermostat, you need to remove it, wait until it warms up to room temperature, and test the contacts. If the device shows a “break” (one on the screen) at room temperature, the thermostat is faulty and requires replacement. In working condition, the contacts should “ring.”
Symptoms of a thermostat failure are often accompanied by a lack of cyclical operation. A normal refrigerator works in cycles: it hums for 15-20 minutes, rests for 30-40 minutes. If there are no pauses at all, and it may even be too cold inside (food freezes at the back wall), this is a sure sign that the sensor is not giving a command to stop.
Refrigerant problems: freon leak
One of the most serious reasons for continuous operation is a refrigerant (freon) leak. If a microcrack has formed in the circuit (often due to corrosion or mechanical damage during cleaning), the gas gradually escapes. The pressure in the system drops, and the available amount of freon is not enough to create the required cold. The compressor works at the limit of its capabilities, trying to gain temperature, but physically cannot do this.
A hot condenser (side walls or rear grille) can be an indirect sign of a leak. Normally, they should be warm, but if the metal is hot to the point that it hurts to touch, and there is heat inside the refrigerator, this is a bad symptom. Also, a uniform “fur coat” may not form on the evaporator inside the freezer, or it will appear only in the corner where the tube comes out.
| Symptom | Probable cause | Action |
|---|---|---|
| The compressor is hot, inside heat | Freon leak or blockage | Call a technician to find the leak |
| The refrigerator hums, but does not cool | Compressor malfunction | Starting diagnostics relay |
| Ice only near the evaporator | Partial refrigerant leak | Circuit charging and soldering |
| No frost, but there is cold | Heating element malfunction defrosting | Checking the No Frost system |
It is impossible to eliminate a freon leak on your own. Special equipment is required to evacuate the system, solder the tubes and fill with new gas. Attempts to simply “add” freon without finding and eliminating the leak will only give a temporary effect, after which the problem will return in a week or month.
Clogged capillary tube and compressor malfunction
There is a narrow section in the freon circulation system - the capillary tube. Through it, the refrigerant under pressure enters the evaporator, where cooling occurs. Over time, a blockage may form in the tube due to oil oxidation products or moisture entering the system. Freon cannot circulate, the pressure at the outlet of the compressor increases, and at the inlet it drops. The motor is overloaded, but does not produce cold.
Another reason is wear of the compressor itself. It has a service life of engine hours. If the piston group is worn out, the compressor may hum, but not create the necessary pressure to compress the gas. In such cases, a metallic clanging or knocking noise is often heard when starting up. Only a specialist can check the performance of the motor using a manometric manifold.
☑️ Diagnostics before calling a technician
If you notice that the compressor is trying to start, it clicks and stalls, or it works, but remains cold (although should warm up), this indicates a mechanical failure. Operating equipment in this condition is dangerous: the motor may burn out completely, and the products may deteriorate.
⚠️ Attention: If you smell burning or see sparking in the area of the start relay (black plastic barrel on the compressor), immediately disconnect the device from the mains. Further activation may lead to a fire.
Failures in the defrosting system (for No Frost)
In refrigerators with a system No Frost continuous operation of the compressor is often associated with freezing of the evaporator. Ice builds up on the radiator inside the case and blocks the flow of cold air. The fan moves the air, but it does not pass through the ice plug. The temperature sensor in the chamber does not detect cooling and keeps the motor on.
The heating element (heater), defrost timer and defrost sensor are responsible for the defrosting process. If the heating element burns out or the relay is stuck, the ice does not melt. As a result, in a week or two a huge lump of ice grows, which blocks the operation of the entire system. Outwardly, this may manifest itself in the fact that it is warm in the refrigerator compartment, but in the freezer the food is in a snowy porridge.
To fix this problem, you need to “ring” the defrost circuit. Often it is the defrost sensor that fails, which does not give the command to turn on the heating element, or the heating element itself. Replacing these parts is usually cheaper than repairing the compressor, and returns the equipment to full functionality.
Algorithm of actions and when to call a technician
If your refrigerator stops turning off, do not panic. Start with simple steps: defrost the unit completely (at least 24 hours), check the seal and make sure the super freeze mode is not on. If, after turning on the network after a day of operation, the problem recurs, or it still doesn’t get cold inside, professional diagnostics are required.
Calling a technician is necessary if:
- 🔧 You find oily spots under the refrigerator (a sign of a freon and oil leak).
- 🔧 The compressor is very overheated (more than 80-90 degrees) or makes extraneous sounds.
- 🔧 There is a smell of burning or plastic inside the chambers.
- 🔧 After complete defrosting, the equipment works normally for no more than 2-3 days.
DIY Repair is only possible if you replace the thermostat, start relay or sensors, if you have skills in working with electricians and a multimeter. All work related to the refrigerant circuit (soldering, refilling) must be performed only by certified specialists with a license to work with freon.
Is it possible to operate a refrigerator if it does not turn off?
For a short time (several hours) - you can while you are waiting for a technician or performing diagnostics. Long-term operation (a day or more) will lead to overheating of the compressor windings, deformation of plastic parts inside the chambers and damage to food. It is not advisable to risk an expensive component to save on diagnostics.
Frequently asked questions (FAQ)
Why does a new refrigerator work without stopping for the first day?
This is normal. After the first load or defrost, the unit takes time to cool the entire internal volume and food to the set temperature. During this period, the compressor can operate continuously. If after 24 hours it does not turn off, this is a cause for concern.
Does hot weather affect the operating time of the refrigerator?
Yes, in the summer, when the room temperature exceeds +30°C, it is more difficult for the refrigerator to release heat to the environment. The compressor operating time increases and pauses become shorter. This is acceptable if the cold remains inside.
Can a faulty socket cause constant operation?
The socket itself will not make the refrigerator work without stopping, but poor contact can cause voltage surges that “glitch” the electronic control module. As a result, the control unit may erroneously keep the compressor on. Check the voltage in the network.
How much does it cost to repair if the refrigerator does not turn off?
The cost depends on the breakdown. Replacing the thermostat or sensor will cost the least. Freon refilling and leak detection are more expensive. The most expensive repair is replacing or overhauling the compressor. The technician will tell you the exact amount after diagnosis.
Is it dangerous to leave a working refrigerator unattended?
If there is a suspicion of a freon leak or a wiring fault (sparking, burning smell), it is dangerous to leave the device unattended. In other cases (just long work) there is no critical danger, but the food may deteriorate due to lack of cold.