The situation when the refrigerator is workingemits the usual working hum, but does not cool inside, is one of the most common and alarming for owners of household appliances. You open the door, expecting the usual chill, but there is room temperature, and the food begins to quickly deteriorate. This scenario often takes you by surprise, because the absence of obvious signs of failure (sparks, smoke, complete silence) is confusing.
In most cases, compressor starts properly and tries to do its job, creating a characteristic noise, but the cooling cycle does not complete. This may indicate a wide range of problems: from a banal blockage in the system to failure of electronic control components. Understanding what exactly is happening inside the unit will help you make the right decision: try to fix the problem yourself or immediately call a technician.
It is important not to panic and carry out initial diagnostics, which often allows you to identify simple operating errors. However, it is worth remembering that cooling system is a complex mechanism that requires careful handling. The following material will help you systematize knowledge about possible causes and methods for eliminating them.
Problems with tightness and door seal
The first thing worth checking if the refrigerator does not freezeis the integrity of the thermal circuit. If warm air from outside constantly enters the chamber, the unit simply does not have time to cool it, working non-stop. The compressor hums, trying to compensate for the heat gain, but the temperature does not drop. Often the culprit is sealing rubber band on the door, which over time dries out, cracks, or simply becomes dirty.
Carefully inspect the perimeter of the door. There should be no food debris, crumbs or sticky residue on the rubber that would interfere with a tight seal. Also check to see if the rubber itself is deformed. If it becomes hard or moves away from the body, the cold will evaporate. In some cases, it is enough to simply wash the seal with warm water and soap to restore its elasticity.
⚠️ Attention: If the seal has deep cracks or tears, no amount of cleaning will help - a complete replacement of the part will be required, otherwise the compressor will burn out from overload.
You can check the tightness using a simple test with a piece of paper. Clamp the sheet with the refrigerator door and try to pull it out. If the paper comes out easily and without resistance, then the seal is broken. Also, the cause of heat inflows may be cracks in the body or a door that is not tightly closed due to skewed hinges.
Thermostat faults and temperature sensors
If thermostat (the thermostat) fails, it may not send a signal to turn on the compressor, even when the temperature in the chamber has risen to critical values. In this case, the refrigerator is silent, but the opposite situation also happens: the sensor is “stuck” in the “on” position, and the motor runs non-stop, hums, but does not freeze, since the control system does not see the real temperature regime.
In modern models with the system No Frost air sensors are responsible for temperature control. If one of them shows incorrect data (for example, “in the chamber -5°C”, although there is +10°C), the electronic module will not start the cooling cycle. Diagnosis of such problems often requires the use of a multimeter to test the continuity of the circuit.
Replacing the thermostat is a procedure that can be performed independently if you have basic skills. It is usually located inside the refrigerator compartment or under the top lid. However, before replacing, make sure that the problem is in the sensor and not in the wiring.
Clogged capillary tube and problems with the refrigerant
One of the most difficult technical The reason why the refrigerator is hummingbut there is no cold is a violation of the refrigerant circulation. A capillary tube may form in the system. This is the thinnest channel through which freon moves under pressure. If moisture gets there, turning into an ice plug, or oil oxidation products, the circulation will stop. clogging capillary tube. This is the thinnest channel through which freon moves under pressure. If moisture gets in there, turning into an ice plug, or oil oxidation products, circulation will stop.
The compressor in this case works with overload, trying to push gas through the obstacle, which is accompanied by a loud hum or even knocking. The pressure in the system increases, but no cooling occurs. It is almost impossible to clean the capillary tube on your own without special equipment (press, nitrogen, vacuum pump).
Symptoms of blockage
On the rear grill of the refrigerator (condenser), only part of the tubes are cooled, or they remain warm, although the compressor is hot and running.
Another option — Freon leak. If a microcrack has formed in the circuit (often due to corrosion), the gas gradually escapes. The compressor hums, running idle, since it has nothing to pump. In this case, it is necessary to search for the location of the leak, seal and refill with a new portion of refrigerant.
Failure of the compressor and start relay
The heart of the refrigerator is compressor. If it hums but does not start (only a humming sound and a click is heard, followed by silence), the problem may lie in the start relay. This small element supplies a starting impulse to the motor windings. If the relay is burned out or stuck, the motor cannot go into operating mode.
In more severe cases, the compressor itself is faulty. An interturn short circuit in the windings leads to the fact that the engine hums, heats up, but does not rotate the pistons. It is impossible to operate the equipment in this condition - it is a fire hazard. A professional diagnosis of winding resistance is required.
If you hear that the motor is running, but very loudly, with vibration and metallic clanging, this may indicate wear on the internal mechanical parts of the compressor. In such a situation replacing the unit is the only way out.
Faults in the No Frost system
In refrigerators with a No Frost system, the reason for the lack of cold when the compressor is running often lies in the defrost system. If the defrost heating element, timer or defrost sensor fails, the evaporator becomes covered with ice. The fan, which is supposed to disperse cold air through the chambers, is blocked by the ice mass or simply does not turn on.
As a result, the compressor freezes the evaporator (which is located behind the back wall), but cold air does not enter the main compartment. You hear the hum of the engine, but the cell is warm. The solution may be to completely defrost the refrigerator within 24 hours.
If after defrosting the refrigerator started working normally, but a week later the situation repeated itself, it means that one of the elements of the defrosting system is faulty. Most often, The defrost heating element burns out or the sensor fails, which does not give a command to turn on the heater.
| Symptom | Possible cause | Complexity repair |
|---|---|---|
| Humming, but not freezing, the condenser is warm | Freon leak or blockage | High (needs a technician) |
| Humming, clicking and turning off | Faulty starting relay | Average (you can do it yourself) |
| Freezes only after defrosting | Failure of the defrost system (No Frost) | Average |
| It hums very loudly, vibrates | Compressor wear | High (replacement of unit) |
Diagnostics and procedure for failure
To understand what to do if the refrigerator is not freezing, follow the initial diagnostic algorithm. You should not immediately disassemble the unit, start with simple steps that will exclude external factors.
First of all, make sure that the equipment is connected to a network with sufficient voltage. Power surges could damage electronics. Then check the temperature settings - perhaps one of the household members accidentally lowered the settings to minimum.
☑️ Primary diagnostics
If simple defrosting did not help, and the seal is intact, a technical malfunction is likely. In this case, you need to evaluate your strengths. Replacing a light bulb or thermostat is accessible to many, but filling with freon or soldering pipes requires a license and special tools.
⚠️ Attention: Under no circumstances try to break through the ice crust on the evaporator with a knife or sharp objects - you will pierce the cooling channels, and repairs will become economically unfeasible.
Frequently asked questions (FAQ)
Is it possible to operate a refrigerator if it hums, but does not freeze?
It is strictly not recommended. The compressor runs idle or overloaded, which will lead to rapid combustion. In addition, the food will spoil, creating a favorable environment for bacteria.
How long does it take to defrost the refrigerator to check?
For complete defrosting and evaporation of moisture from hard-to-reach places (especially in the No Frost system) it takes from 12 to 24 hours. Simply waiting for an hour may not be enough.
Why is the back wall of the refrigerator hot, but there is no cold?
This is a normal process of heat release by the condenser if the system is working correctly. But if it's warm inside but hot behind you, this is a sign that the refrigerant is circulating but not cooling (possibly due to a clog or compression problems).
You can hear the sound of water running, but the refrigerator is not freezing. Is this normal?
The sound of overflowing liquid is the normal movement of freon through the system. However, if there is no cooling, then the cycle is broken (insufficient amount of gas or lack of compression).
Is it worth repairing an old refrigerator or is it cheaper to buy a new one?
If you need a complex compressor replacement or repair of a sealed circuit on a model older than 7-10 years, it is often more profitable to purchase new equipment. Repairing thermostats, relays or fans is usually economically justified.