The situation when the refrigerator is constantly running and does not turn off is familiar to many owners of household appliances. At first, this may seem like a sign of working hard on a hot summer day or after a heavy load of groceries. However, if the motor hums for days on end, and an ice crust forms on the walls of the chamber, it becomes impossible to ignore the problem. This is not just an annoying noise, but also a signal of a serious malfunction in the thermoregulation system.
Constant operation of the compressor leads to accelerated wear of parts and a significant increase in electricity bills. In some cases, the unit may even stop freezing, despite the continuous hum. Inverter models in this regard, they are more economical, but they should not work at the limit of their capabilities without interruptions. Understanding the root cause will help you avoid costly repairs or complete replacement of equipment.
In this article we will examine in detail the mechanical and electrical factors that influence the engine operating cycle. You will learn how to carry out initial diagnostics yourself and in what cases you need to call a specialist. It is important to distinguish between normal operation and emergency mode in order to prevent damage to products.
Violation of the tightness of the door seal
One of the most common reasons why the refrigerator does not turn offis the loss of sealing of the chamber. If warm air from the room enters the system, sensors detect an increase in temperature and command the compressor to work harder. Often the culprit is the rubber seal around the perimeter of the door. Over time, it dries out, cracks or deforms, no longer fitting tightly to the body.
You can check the condition of the seal visually and tactilely. Run your hand along the entire surface of the elastic - it should be smooth, without tears or creases. If you notice that the door does not fit tightly or there is a gap visible in some places, this is the problem. It is also worth checking whether food or dishes are preventing the door from closing tightly.
⚠️ Attention: Do not use aggressive chemicals to wash the seal, this may accelerate its destruction. Wipe the rubber with a soft cloth and soapy water.
To eliminate the problem, it is often enough to wash and dry the seal. If the rubber has simply come off, it can be carefully glued with special glue. In more complex cases, the entire element will need to be replaced. Make sure that the door hinges are not skewed, as this also affects the tightness of the seal.
Thermostat malfunctions and sensors
The thermostat (thermostat) is the “brain” of the refrigerator, which is responsible for turning the compressor on and off. If this element fails, it can constantly send a signal that the temperature inside the chamber is higher than normal. As a result the refrigerator runs non-stoptrying to achieve a non-existent ideal. In older models, the thermostat is mechanical, in modern ones it is electronic.
Diagnostics of the thermostat requires caution. On mechanical models, you can try temporarily closing the contacts to see if the motor will start. If the compressor starts working after closing the contacts, then the problem is in the thermostat itself. Electronic temperature sensors (thermistors) are checked for resistance with a multimeter.
- 🔧 Symptoms of failure: the compressor hums constantly, the temperature in the chamber is too low or, conversely, the products begin to deteriorate.
- 🔧 Mechanical thermostat: often has a capillary tube, which should be in close contact with evaporator.
- 🔧 Electronic module: may display an error on the display if one of the sensors shows incorrect values.
Replacing the thermostat is not a complicated procedure, but requires precision. It is necessary to select an analogue with identical parameters. If you are not confident in your abilities, it is better to entrust this work to a specialist, since incorrect installation can lead to further damage.
How to check a thermostat with a multimeter?
To check, remove the thermostat and immerse its sensitive tube in a container with cold water (about 3-5 degrees). Then test the contacts with a multimeter. If the resistance has not changed or the circuit does not close/open when the temperature changes, the part is faulty.
Problems with the defrost system (No Frost)
In refrigerators with the system No Frost continuous operation of the compressor is often associated with a violation of the defrost cycle. If the evaporator is overgrown with a “coat” of ice, the cold cannot effectively circulate through the chamber. The temperature sensor does not detect cooling, and the motor continues to run. The main culprits here are: defrost heating element, timer or defrost sensor.
A symptom of such a malfunction is often that the back wall in the freezer is covered with a thick layer of ice, while in the refrigerator compartment, on the contrary, it is warm. Ice blocks air passages. In this case the refrigerator does not gain temperature, although the compressor is working hard.
| System element | Function | Fault symptom |
|---|---|---|
| Defrost heating element | Heats the evaporator to melt the ice | The ice does not melt, the heating element is cold when turned on |
| Defrost sensor | Controls the evaporator temperature | Does not give a command to turn on the heating element |
| Timer/Module | Regulates operating and defrosting cycles | Chaotic operation or lack of defrosting |
| Fan | Cold air circulates | Ice freezes unevenly, noise during operation |
To fix the problem, it is often necessary to completely defrost the refrigerator within 24 hours. If after this the equipment worked normally, but a week later the situation repeated itself, the failed element of the defrosting system needs to be replaced.
☑️ Diagnostics of the No Frost system
Freon leak and problems with the compressor
If The refrigerator hums, but does not freeze, there is a high probability of refrigerant (freon) leakage. When the level of freon in the system is low, the pressure drops and the compressor cannot create the necessary cold. Sensors detect high temperatures and do not give a command to stop the engine. The compressor runs idle, trying to compensate for the lack of refrigerant.
A leak can occur anywhere in the circuit: in the foamed part of the housing, in the evaporator or in the places where the tubes are soldered. Often, a leak is indicated by swelling on the walls of the refrigerator or oily spots under the appliances. Another sign may be a hot condenser (grid at the back) in only one part or its complete coldness.
⚠️ Attention: Independent refilling with freon is impossible without special equipment and a license. Trying to repair it yourself can lead to complete failure of the compressor.
The compressor may also be mechanically faulty. Wear of the piston group or valves leads to a drop in performance. The motor hums and vibrates, but does not create enough pressure in the system. In such cases, it is often necessary to replace the compressor or the entire refrigeration unit.
The influence of external factors and operating rules
Sometimes the reason lies not in a breakdown, but in improper operation. If you have just loaded a large amount of warm food into the chamber, the refrigerator will work longer usual to stabilize the temperature. This is normal operating mode, but it should not last for days.
The location of the equipment also plays a role. Installing the refrigerator near heating appliances, in direct sunlight or in a niche without ventilation gaps leads to overheating of the condenser. Heat is not removed effectively, and the cooling system works under increased load.
- 🌡️ Room temperature: if the room is hotter than +30°C, the refrigerator can work almost without interruption.
- 🌡️ Gaps: leave at least 5-10 cm from the back wall to the furniture for air circulation.
- 🌡️ Loading: do not fill the chamber with food to capacity, cold air should circulate freely.
Check the temperature settings. If you accidentally set the minimum temperature (maximum cold) or turned on the “Super Freeze” mode and forgot to turn it off, the equipment will work constantly. Return the settings to 3-4 or Eco for normal operation.
Failure of the electronic control module
In modern electronically controlled models, the main module is responsible for all processes. If a relay burns out on the control board or a firmware failure occurs, the signal to turn off the compressor may not be received. The electronics “think” that it needs to be cooled and keeps the circuit closed.
It is difficult to diagnose this problem at home. It is often accompanied by chaotic behavior of indicators on the panel, spontaneous turning on and off of the light in the camera, or lack of response to buttons. Electronic module sensitive to power surges in the network.
Repairing the module requires a qualified approach. The technician can resolder the burnt elements or replace the entire board. In some cases, a simple reset (Hard Reset) helps, but if the problem is in the hardware, you cannot do without repairs.
Is it possible to repair the control module yourself?
If you have skills in working with a soldering iron and electronics, you can try to find visually burnt parts (swollen capacitors, blackened tracks). However, without a schematic diagram and experience in diagnosing specific components, there is a high risk of making things worse. It’s easier and safer to order a replacement board.
Why does a new refrigerator last longer than an old one?
Modern refrigerators often work longer, but are quieter and more economical than older models. This is due to the use of inverter compressors and improved thermal insulation. They do not turn off completely, but only reduce the speed, maintaining the temperature. This is the norm, not a breakdown.
How often should the refrigerator turn off?
In normal mode, the operating cycle is: 15-20 minutes of work and 20-40 minutes of rest. The ratio may vary depending on the load and room temperature. If the refrigerator works for 2 hours without a break, this is a cause for concern.
Does seasonality affect the operation of the refrigerator?
Yes, in the summer the load on equipment increases. In a hot room, it is more difficult for the refrigerator to release heat, so the operating time of the compressor increases. In winter, on the contrary, cycles may become less frequent. This is a natural physical process.