The situation when a household refrigerator stops stopping the cooling cycle is an alarming signal for any owner. During normal operation, the compressor unit turns on and off at certain intervals, maintaining the set temperature. If the motor hums continuously or the pauses between starts become negligible, this indicates a violation of the tightness of the circuit or failures in the control system.
Continuous operation of the engine leads to its overheating and accelerated wear of moving parts. Compressor, designed for cyclic load, quickly exhausts its resource in non-stop mode. In addition, electricity bills increase significantly, since the refrigerator is one of the most energy-intensive appliances in the house.
It is important to understand that the reasons can be either trivial, associated with improper operation, or complex technical malfunctions. Inverter models may work longer than usual, but they should not hum without break for hours. Ignoring the problem at an early stage can lead to the need for expensive major repairs or complete replacement of equipment.
Refrigerant leakage as the main reason for continuous operation
The most common reason that the refrigerator does not turn off is a partial or complete freon leak. The refrigerant circulates in a closed circuit, taking heat from the chambers and releasing it to the environment through the condenser. If the tightness of the system is broken, the amount of gas decreases and the efficiency of heat transfer decreases.
The thermostat or electronic control module “sees” that the required temperature in the chambers has not been reached and commands the compressor to work without stopping. In this case, even prolonged operation of the engine cannot compensate for the lack of refrigerant. Evaporator in this case, it may become covered with an ice crust unevenly, or cooling will completely disappear in one of the chambers.
It is almost impossible to independently detect microcracks in tubes or solder joints without special equipment. Leaks often occur in the foamed part of the housing or at factory connections. Signs may include swelling of the side walls or the appearance of oily spots in the compressor area.
Why can’t you just add freon?
Simply refilling the refrigerant without finding and eliminating the leak is a temporary measure that will not solve the problem. Freon will escape through the crack again in a few days or weeks. In addition, air and moisture could have entered the system, which requires mandatory vacuumization of the circuit before refilling.
To eliminate the malfunction, you need to call a technician who will pressurize the system with nitrogen, find the location of the damage and restore the tightness. Only after this is evacuation and refilling with new refrigerant carried out in compliance with weight standards.
Malfunctions of the thermostat and temperature sensors
In older models of refrigerators, a mechanical thermostat is responsible for controlling the temperature. Inside its bellows tube is a heat-sensitive liquid or gas. As the temperature changes, the pressure inside the tube changes, opening or closing electrical contacts. If the mechanism sticks in the “on” position, the compressor will work continuously.
In modern units with a system No Frost and electronic control, the control function is performed by sensors (thermistors). They transmit data to the nano module. If the sensor “lies” and shows that the chamber is warmer than it actually is, the refrigerator will try to cool the space to impossible values.
- 🔧 Displacement of the capillary tube: in mechanical thermostats, the tube could move away from the evaporator, which is why it does not feel real cooling.
- ❄️ Malfunction of the defrost sensor: if it does not register the heating of the evaporator, the system may not start defrosting, which leads to ice accumulation and constant operation of the fan and compressor.
- ⚡ Electronic module failure: the “brains” of the refrigerator may incorrectly interpret signals from the sensors due to a power surge or factory defective.
Diagnostics of the thermostat is often carried out by elimination or by direct replacement with a known-good element. In electronic systems, the technician reads error codes that may indicate an open circuit of the sensor or a short circuit.
⚠️ Attention: An attempt to independently replace the electronic control module or reflash it without the appropriate experience and equipment can lead to the final failure of the equipment. The electronics of refrigerators of different series, even of the same brand, may differ.
Wear of seals and violation of chamber seals
Tight fit of the doors to the refrigerator body is the key to efficient operation. The rubber seal (cuff) prevents the penetration of warm air from the room into the chambers. Over time, the rubber loses its elasticity, cracks or deforms, forming gaps.
When warm air enters through a door that is not tightly closed, the temperature inside rises. Sensors record the increase in degrees and make the compressor work harder. In winter, when the temperature difference between the street and the apartment is large, this effect is enhanced.
Often the cause is not the wear of the rubber itself, but contamination of the folds or misalignment of the door. Dirt and grease make the rubber slippery and prevent it from pressing tightly to the metal. In some cases, the door may warp due to weakening of the hinges or the heaviness of the products on the shelves.
You can restore the elasticity of the seal using hot water or a special rubber conditioner. If the cuff is torn or severely deformed, it will need to be replaced. Adjusting the door hinges can also solve the problem of loose closing.
Problems with the defrost system (for No Frost refrigerators)
Refrigerators with a system No Frost automatically get rid of ice on the evaporator. A heating element (heating element), defrost timer or defrost sensor is responsible for this process. If one of these elements fails, a “coat” of ice grows on the evaporator.
The ice layer acts as a heat insulator. The refrigerator is trying to cool the chamber, but the ice interferes with the heat exchange between the evaporator and the air. As a result, the compressor works non-stop, trying to break through this barrier, but the temperature in the chamber may even rise.
An indirect sign of such a malfunction is the absence of the characteristic sound of water dripping into the drain pan (if you listen at the moment when defrosting should occur) or the appearance of puddles under the refrigerator. The fan may also stop working if it is covered in ice.
To solve the problem, you need to defrost the refrigerator completely (for 24 hours) so that the ice melts naturally. If, after turning on in normal mode, the problem recurs after a few days, it means that the heating element, defrost sensor or timer needs to be replaced.
The influence of external factors and operating conditions
The reason is not always a breakdown. Often, users themselves create conditions under which the refrigerator is forced to work in increased mode. It is important to analyze where and how the equipment is installed.
The location of the refrigerator next to heat sources (radiators, ovens, direct sunlight) forces it to constantly fight external heat. It is also critically important to have a gap between the back wall of the refrigerator and the wall for free air circulation.
- ☀️ Direct sunlight: heat the body, increasing the load on the condenser.
- 🔥 Proximity to the stove: hot air from the burners significantly increases the temperature around the unit.
- 🧱 Tight fit to the wall: impairs heat removal from the radiator located at the back or on the sides.
Another factor is the loading of the chambers. If you put a large amount of warm or just defrosted food in the refrigerator, it will take a long time for it to reach its normal setting. In this case, prolonged operation of the compressor in the first 5-10 hours is the norm.
Check the settings as well. If you accidentally set the “Super Freeze” mode or turn the temperature control to maximum, the refrigerator will work continuously until you return the settings to normal.
Comparison of symptoms: how to distinguish one malfunction from another
Diagnostics requires careful observation of the behavior of the equipment. Different breakdowns have their own characteristic signs that help narrow down the search for the problem.
| Symptom | Probable cause | Additional symptoms |
|---|---|---|
| The compressor is hot, but there is no cold | Freon leak | Quiet humming, no characteristic bubbling in the pipes |
| The refrigerator freezes, but does not turn off | Thermostat is faulty | Food in the main chamber may freeze |
| Ice build-up on the back wall | Failure of the defrost system | The fan may hum or go silent, there is water in the sump |
| The engine runs, but does not heat up | Loss of compressor performance | The compressor may start and immediately stall (click) |
Pay attention to the sounds. Normal operation is accompanied by a steady hum. A knocking, grinding or intermittent hum may indicate mechanical problems inside the compressor or a faulty start relay.
When it is necessary to call a specialist
There are a number of situations when attempts at self-repair can be not only useless, but also dangerous. If you have checked the tightness of the doors, defrosted the unit and made sure that the settings are correct, but the problem has not disappeared, professional intervention is required.
It is especially dangerous to carry out repairs if there is a suspicion of a gas leak or problems with the electrical part. Refrigerants can be flammable or toxic in certain concentrations, and high voltage in the compressor circuit is dangerous.
⚠️ Warning: Opening a sealed compressor or tampering with the integrity of the refrigeration circuit without a license and special equipment is prohibited. This can lead to property damage and injury.
The technician will arrive with the necessary supply of spare parts and tools. He will be able to accurately determine whether it is worth repairing the old refrigerator or whether it is more economically feasible to purchase a new one. Often, compressor repair costs more than 50% of the cost of new equipment, which makes it pointless.
☑️ Checklist before calling a technician
A timely call to a specialist will help preserve food and avoid more serious damage. Ignoring the problem of “rare shutdowns” ultimately leads to a complete failure of the equipment.
Can a refrigerator not turn off due to the heat in the room?
Yes, if the room temperature exceeds 30-32 degrees, the refrigerator may not have enough power to remove heat. The capacitor does not have time to cool down, and the cycle is not interrupted. In such conditions, the equipment operates at the limit of its capabilities.
How long should a compressor operate normally?
Operation and downtime times depend on the model and load, but usually the ratio is approximately 1:2 or 1:3. That is, 10-20 minutes of work and 30-40 minutes of rest. In hot weather or when fully loaded, the operating time may increase.
Is it dangerous to leave the refrigerator on all the time?
For a short time (several hours) - not dangerous. But if it works in this mode for days, this will lead to overheating of the motor windings, melting of the insulation and a fire. In addition, the compressor itself will quickly fail.
Why does a new refrigerator not turn off for a long time after being turned on?
When you turn it on for the first time, the refrigerator needs to cool the entire internal volume and enter operating mode. This process can take from 3 to 10 hours. At this time, the compressor can work without interruption, which is absolutely normal.
Does the amount of food affect the operating time?
A full refrigerator keeps the cold better, since the food accumulates temperature. An empty refrigerator heats up faster when the door is opened, which causes the compressor to turn on more often. However, sudden loading with warm products will cause the motor to run for a long time.