The situation when the refrigerator makes the usual hum, the light inside is on, but the food begins to deteriorate can take any owner by surprise. The internal volume of the chamber remains warm, although the unit outwardly looks serviceable and consumes electricity. Lack of cold with the engine running - this is a classic symptom indicating a violation of the refrigerant circulation cycle or a failure in the control system.
Before calling a technician, it is worth conducting an initial diagnosis to understand scale of the problem. Often the reason lies in banal things, such as a loosely closed door or broken settings, but sometimes we are talking about a serious freon leak. Modern models With the No Frost system, old two-chamber units can behave differently, so it is important to listen carefully to the sounds of the engine.
In this article we Let's look at the main reasons why The compressor is humming, but there is no cooling, and determine what steps you can take yourself. Understanding the principles of operation of the refrigeration circuit will help you avoid unnecessary expenses for repairs or, conversely, stop the operation of dangerous equipment in time.
Checking the door tightness and tightness
The most common and easily eliminated cause of loss of cold is a violation of the tightness of the refrigeration unit cameras. If the rubber seal on the door is worn out, dirty or deformed, warm air from the room constantly flows inside. The compressor tries to compensate for the heat by working without interruption, but due to the constant flow of heat, the temperature does not drop to the required values.
Pay attention to the condition of the magnetic tape. Over time, it may weaken or become covered with a sticky coating that prevents a tight seal. It is also worth checking whether bulging food packaging or an incorrectly installed shelf is preventing the door from closing. Even a minimal gap of a few millimeters can completely disrupt thermodynamic balance inside the chamber.
⚠️ Attention: If you notice that the seal is cracked or hard to the touch, replacing it is the only effective way to solve the problem. Attempts to lubricate it with oil will only give a temporary effect.
To quickly check the tightness, you can use a simple method with a sheet of paper. Press the door around the perimeter of the sheet and try to pull it out. If the paper is pulled out without resistance, it means in this place the seal is broken. Pay special attention to the corners of the door, where wear occurs most quickly.
Thermostat faults and temperature sensors
If the refrigerator works but does not freeze, the problem may lie in the “brain” of the cooling system - the thermostat. This element is responsible for turning the compressor on and off depending on the temperature inside the chamber. Old models use a mechanical one, which over time loses sensitivity or sticks in the “off” position. thermostat, which over time loses sensitivity or gets stuck in the “off” position.
In modern electronically controlled units, the control function is performed by temperature sensors (thermistors). If such a sensor fails and transmits incorrect data to the control module, the refrigerator may “think” that it is already cold inside and not start the compressor, or, on the contrary, hum in vain. Diagnostics of the electronic unit requires special equipment, but a mechanical thermostat can be checked visually.
Often, a breakdown of the thermostat is accompanied by the absence of a characteristic click when turning the adjustment knob. If you turn the knob from minimum to maximum, but there is no click, and the motor does not start (or does not stop), it is likely malfunctioning. It is also worth checking the capillary tube of the thermostat for damage.
It is important to note that in two-chamber refrigerators with one compressor, flon regulatoris often used, which distributes the cold between the chambers. If it is stuck in the closed position, cold will stop flowing into one of the chambers (usually the refrigerator), although everything will work fine in the freezer.
Problems with refrigerant circulation: freon leak
One of the most serious reasons why the refrigerator stopped working freezing is a refrigerant leak. Freon is a working fluid that circulates through the system, taking heat from the chambers and releasing it into the environment. If a microcrack forms in the circuit, the gas gradually evaporates and the cooling efficiency drops to zero.
A leak can occur anywhere: in the foamed part of the housing, in the evaporator or at the joints of the tubes. Often the cause is metal corrosion or mechanical damage due to careless defrosting. If you notice oily spots on the floor under the refrigerator or on the rear grill, this is a sure sign of depressurization of the system, since freon circulates along with compressor oil.
| Symptom | Probable cause | Action |
|---|---|---|
| Compressor hot, but cold | Clogged capillary tube | The system needs to be purged |
| The motor runs constantly | Freon leakage or compressor wear | Call a technician to search leaks |
| The refrigerator turns on for 1-2 minutes | The thermal protection relay has tripped | Checking the starting relay and windings |
It is almost impossible to independently find the leak and fill the refrigerator with freon without special equipment (vacuum pump, pressure gauge station and leak detector). Attempts to simply “add gas” without eliminating the cause and evacuation of the system will lead to rapid re-breakdown and failure of the compressor compressor.
⚠️ Attention: Freon is odorless and colorless, so its leak cannot be detected by smell. Beware of open sources of fire near a running refrigerator if you suspect a leak, as some types of refrigerants are flammable.
Faults of the compressor and start relay
The heart of the refrigerator - the compressor - may not work correctly, creating the appearance of normal operation. If the unit hums, but does not start fully, or turns on for a few seconds and clicks, the problem often lies in starting relay. This small element provides an impulse to start the motor, and if it burns out, the compressor cannot gain speed.
A more serious situation is an interturn short circuit of the motor windings or jamming of the piston group. In this case, the motor may hum, trying to start, but the shaft does not rotate. Prolonged operation in this mode leads to overheating and thermal protection. If you feel a strong burning smell or see that the compressor housing is hot, immediately unplug the device.
☑️ Compressor diagnostics
In some cases, the compressor works, but does not create the necessary pressure for freon circulation. This may be due to the exhaustion of the valve life. Externally, the engine runs quietly and smoothly, but there is no cold. Compressor diagnostics require measuring the output pressure and current, so you can’t do without a technician.
How to check the starting relay?
Remove the relay from the compressor and shake it. If the knocking of the ball is heard inside or traces of burning and melting are visible, the part needs to be replaced. You can also call the contacts of the multim--WIDGET:spoiler:
Failure in the defrosting system (for No Frost models)
In refrigerators with the system No Frost or “Crying Evaporator” a working defrost system is critical. If the heating element (heating element), defrost timer or defrost sensor fails, a “coat of ice” begins to grow on the evaporator. Over time, the ice completely blocks the channels through which cold air should enter the chambers.
As a result, the fan hums, the compressor works, but the air does not circulate. You may notice that the back wall of the refrigerator is covered with a thick layer of frost or ice, but it is warm inside. Sometimes ice blocks the sensor door, and the refrigerator “thinks” that the door is open, stopping cooling.
Diagnostics often require completely defrosting the unit within 24 hours. If after defrosting the refrigerator begins to freeze normally, but after 1-2 weeks the problem returns, it means that the auto-defrost system is faulty. It is necessary to check the circuit: Evaporator heating element → defrost sensor → timer or control module.
Clogged capillary tube and other technical nuances
A rare but possible reason for the lack of cold is a clogged capillary tube. In the freon circulation system, this is the narrowest section where the refrigerant changes from liquid to gaseous. If moisture, oil oxidation products or foreign particles get into the system, a plug forms.
If there is a blockage, the compressor works with increased load, trying to push freon, but circulation stops. A characteristic symptom is that the condenser (grid at the back) remains cold or warm only at the beginning, and the filter drier may become covered with frost. To eliminate this, you need to purge the system with nitrogen under high pressure and replace the filter-drier.
It is also worth mentioning problems with the fan in the No Frost system. If the fan has stopped, the cold will not spread through the chambers, even if the evaporator is icy. You can check its operation by opening the refrigerator door (in many models, when the door is open, the fan stops; you need to press the door sensor with your finger, simulating closing).
Why does the refrigerator freeze in only one compartment?
This often indicates a malfunction of the damper that regulates the flow of cold air between the freezer and refrigerator compartments, or a circulation problem due to icing of channels. Freon leakage is also possible when its quantity is only sufficient for partial cooling.
Is it possible to operate a refrigerator if it does not freeze?
It is strictly not recommended. A running compressor without heat transfer quickly overheats, which can lead to it jamming or the start relay burning out. In addition, food spoils, creating a favorable environment for bacteria.
How long should the refrigerator cool down after turning it on?
Usually it takes from 2 to 12 hours to reach operating temperature, depending on the model, the volume of the chambers and the room temperature. If after 12 hours of compressor operation the inside has not become colder than the room, then there is a malfunction.
Does the amount of food affect the cooling rate?
Yes, an empty refrigerator cools faster, but holds the temperature worse when the door is opened. However, an excessive amount of warm food can overload the compressor, causing it to wear out without reaching the target temperature.