The situation when you open the refrigerator door and there is room temperature inside can ruin anyone’s mood. It becomes especially alarming if the unit seems to be humming, the light is on, but the food begins to spoil. This is a classic signal that there is a failure in the refrigerant circulation or temperature control system that requires immediate intervention.
Before calling a technician or looking for a service center, it is worth conducting an initial diagnosis yourself. Often the reason lies in trivial things: incorrect installation, clogged drainage or incorrect settings. However, in 70% of cases the problem is of a technical nature, associated with a gas leak or failure of compression units.
In this article we will analyze in detail the mechanics of the cooling process, list the main breakdowns from simple to complex and tell you what to do in each specific case. Understanding the operating principle will help you not only save on repairs, but also prevent a recurrence of the situation in the future.
1. Violation of the rules of operation and placement
The most common reason that the refrigerator has stopped freezingis banal to the point of indecency. The unit vitally needs an influx of fresh air to cool the condenser (black grille at the back). If the equipment is placed close to the wall or in a niche without gaps, the heat is not removed, and the compressor works for wear and tear, without creating the necessary cold.
The second important nuance is the tightness of the chamber. Rubber seal on the door it dries out over time, cracks, or simply gets dirty with crumbs. Warm air constantly enters through microscopic cracks, and the system simply does not have time to cool it.
It is also worth checking the temperature conditions. If you set the regulator to minimum (maximum cold) in a hot room, the compressor may go into overheat protection. In this case, the unit just stands there and does not turn on until it cools down.
⚠️ Attention: The minimum distance from the back of the refrigerator to the wall must be at least 5-7 cm. Ignoring this rule reduces the cooling efficiency by 30% and shortens the service life of the motor.
2. Malfunction of the thermostat or temperature sensor
The thermostat (thermostat) is the “brain” of the refrigerator, which gives the command to turn the compressor on and off. In old models it is a mechanical part with a capillary tube, in modern ones it is electronic. If it fails, the refrigerator “does not understand” that it has become warm inside and simply does not start the cooling cycle. temperature sensor. If it fails, the refrigerator “does not understand” that it has become warm inside and simply does not start the cooling cycle.
Signs of a thermostat failure are quite specific: the unit is silent, although it is warm in the chamber, or, conversely, it works without interruption, causing severe freezing of the back wall. In mechanical models, lightly tapping the regulator knob often helps, which can temporarily restore contact.
For electronic systems, the readings tend to go into error. If a fault code appears on the display or the indicator blinks, the sensor most likely requires replacement. Self-diagnosis is possible using a multimeter, but requires disassembling the control panel.
3. Freon (refrigerant) leak
One of the most serious problems is refrigerant leak. Freon circulates in a closed circuit, and if a microcrack appears in the tubes or evaporator, the gas evaporates. Without a working fluid, heat exchange is physically impossible: the compressor drives empty space, and there is no cold.
Often a leak occurs in the foamed part of the housing (inside the wall) due to corrosion or manufacturing defects. Visually, this can be seen by swelling of the side walls of the refrigerator or the appearance of rusty spots. A hot compressor while the engine is running may also be a sign.
Restoring the system in the event of a leak is a complex process. You need to find the location of the damage, solder it, replace the filter-drier and refill the circuit with freon under vacuum. It is almost impossible to do this with your own hands without special equipment.
Below is a table that helps differentiate a leak from other problems:
| Symptom | Freon leak | Thermostat malfunction | System clogged |
|---|---|---|---|
| Compressor operation | Works constantly or for a long time | Does not turn on or works without stopping | Works jerkily, turns off with a click |
| Temperature condenser | Cold or barely warm | Warm (if turned on) | Hot only to the point of blockage |
| Frost in the freezer | No or uneven | Abundant or absent | Absent |
4. Problems with the compressor and start relay
The compressor is the heart of the refrigeration unit. If it fails, there will be no cold anywhere. However, often it is not the motor itself that is to blame, but start-protection relay. This is a small part that provides the starting impulse. If the relay burns out, you will hear a characteristic click, an attempt to start and a click again - the motor hums for a couple of seconds and then goes silent.
If the compressor hums smoothly, but does not pump freon (the valves are broken), or is generally silent when voltage is applied directly, these are signs of its demise. Replacing a compressor is an expensive procedure that requires professional sealing of tubes and refilling.
In modern inverter models LG or Samsung the problem may lie in the inverter control module. It converts the current to start the motor smoothly. Diagnostics of such systems requires a service menu and a tester.
5. Clogged capillary tube
The capillary tube is a thin channel where a pressure difference is created to evaporate freon. Over time, oil oxidation products or moisture can accumulate in the system, which turns into an ice or dirt plug. This phenomenon is called clogging of the capillary tube.
The symptoms are similar to a leak: the compressor works, but there is no cold. The difference is that the condenser (grid at the back) will only be half hot, and after the clogged area it will be cold. Also, the motor can quickly heat up and be turned off by a thermal relay.
Removing blockages at home is impossible. The system requires purging the system with nitrogen under high pressure, replacing the filter drier and vacuuming. Sometimes it is possible to “break through” the blockage by tapping, but this is a temporary measure.
⚠️ Attention: Under no circumstances try to pierce the pipes or open the system if freon remains in it. The release of gas under pressure is dangerous, and moisture getting inside will instantly damage the compressor.6. Malfunctions in the No Frost system
If you have a refrigerator with the system No Frost and it stops freezing, while the fan in the freezer does not spin or you hear extraneous noise, the problem may be in the defrost system. A snow coat could have grown on the evaporator inside the housing and blocked the air channels.
In this case, the cold simply does not reach the main chamber. Often the defrost heating element, timer or defrost sensor is to blame. This can be seen visually if you remove the back panel in the freezer (after defrosting the refrigerator).
If after complete defrosting (for 24 hours with the doors open) the refrigerator worked normally, but a week later the situation repeated itself, one of the elements of the defrosting system is definitely faulty. It is necessary to test the heating element and replace the burnt element.
Frequently asked questions (FAQ)
Why is the refrigerator humming but not cooling, and what to do first?
Most likely, there is a freon leak or the system is clogged. First of all, defrost the unit completely (24 hours). If after turning on the problem returns after a few hours, call a technician to look for a leak.
Is it possible to operate a refrigerator if it does not freeze well?
It is strictly not recommended. The compressor operates in emergency mode, which will lead to its overheating and eventual combustion. In addition, food in a warm chamber will quickly deteriorate.
How much does it cost to replace freon and is it worth doing?
The cost depends on the model, but usually refilling and leak detection make up a significant portion of the repair cost. If the refrigerator is more than 10 years old, it is often cheaper to buy a new one than to repair an old one with a broken circuit.
Why does the upper chamber not cool, but the lower one freezes?
This is a typical problem for two-compressor models (the upper compressor or thermostat is faulty) or for the No Frost system (the air supply channels are clogged or faulty fan).