The situation when you open the refrigerator door, and the heat inside or the food has begun to thaw, always causes panic. This is not just a household inconvenience, but a direct threat to the safety of supplies and the safety of your health. Often, equipment owners immediately look for the technician’s phone number, believing that the unit has completely failed and requires expensive repairs or replacement.
However, it is too early to rush to conclusions. Statistics from service centers show that a significant portion of calls are related to problems that can be solved independently in a matter of minutes. Before sounding the alarm, it is necessary to carry out an initial diagnosis to understand whether the problem lies in the breakdown of complex components or in a banal violation of operating rules.
In this article we will analyze in detail the main reasons why The refrigerator has stopped coolingand create an algorithm of actions to identify the malfunction. Understanding the principles of operation of the compressor, evaporator and heat removal system will help you save time and money, as well as extend the life of your household appliances.
Primary diagnosis: simple reasons for the lack of cold
Before disassembling the back wall or checking the electrical circuits, it is worth eliminating basic errors. Very often the refrigerator does not freeze due to the fact that heat transfer is disrupted or the settings are lost. Check whether the door fits tightly to the body. If the seal (cuff) is dirty or deformed, warm air constantly enters inside, and the unit simply does not have time to cool it.
The second important point is the operating mode. Perhaps one of the household members accidentally switched the temperature regulator to the “0” or “Min” position. It is also worth paying attention to the location of the equipment: if the refrigerator is located close to the wall or heating devices, the radiator cannot effectively transfer heat to the environment.
⚠️ Attention: If you have just defrosted the refrigerator or transported it, do not turn it on immediately. The oil in the compressor needs time (from 2 to 8 hours) to drain into the crankcase, otherwise water hammer and unit failure are possible.
The third factor is chamber overload. If you have just loaded a large amount of warm food, temperature conditions it may take a few hours to recover. In modern models with the system No Frost air circulation can be temporarily disrupted by dense packing of packages.
To quickly check the condition of the unit, use this mini-checklist:
☑️ Express performance check
Malfunctions of the thermostat and temperature sensors
One of the most common reasons why the refrigerator does not gain temperatureis the failure of the thermostat. This small device is responsible for turning the compressor on and off depending on the temperature in the chamber. If the thermostat is “stuck” in the “Off” position, the motor simply will not receive a signal to start.
In models with electronic control, air sensors are used instead of a mechanical thermostat. Their readings may be distorted due to oxidation of the contacts or a software failure of the control module. In this case, errors may appear on the display, or the temperature will be displayed incorrectly, although the food has already deteriorated.
Diagnostics of a mechanical thermostat is often carried out by the method of exclusion. If, when you turn the regulator knob, you do not hear a characteristic click, and the compressor is silent, there is a high probability of its breakdown. However, in some cases, the problem may be in the wiring itself going to the sensor.
How to check a thermostat with a multimeter?
To check, you need to remove the thermostat, set the multimeter to dial mode and connect the probes to the contacts. At room temperature the chain should ring. If you place the sensor in the cold (for example, on the bottom shelf of the refrigerator or in the snow) for 15 minutes, the circuit should break. The absence of changes indicates a malfunction of the part.
It is important to note that replacing the thermostat is a procedure accessible to a home craftsman, but requires care. Incorrect installation of the capillary tube of the new sensor can lead to incorrect operation of the entire system.
Problems with the compressor and start relay
The heart of any refrigerator is the compressor. If you hear humming, clicking, but no cold, or the unit turns on for a few seconds and immediately turns off, the problem is most likely in the start protection relay or the motor itself.
The start relay is responsible for starting the compressor motor. Over time, the contacts in it burn out, or the internal coil breaks. As a result, the compressor hums, trying to start, but cannot turn the shaft, after which the thermal protection is triggered. Replacing the relay is an inexpensive and quick repair.
A more serious situation is an interturn short circuit of the compressor windings or its mechanical wear. In this case, even with a working relay, the motor will either not start at all or will work extremely inefficiently, not creating the necessary pressure in the system. Compressor diagnostics requires special skills and tools.
| Symptom | Probable reason | Necessary actions |
|---|---|---|
| Silence, no reaction | Open circuit, thermostat burned out | Check voltage, ring thermostat |
| Humming and clicking | The starting relay is faulty | Replace the starting relay |
| The motor housing is getting hot | The compressor is jammed | The compressor needs to be replaced |
| Working constantly | Freon leak or clogged filter | Call a technician to find a leak |
If you do not have the skills to work with high voltage and electrical engineering, climb inside the compressor compartment yourself strongly not recommended due to the risk of getting a shock current.
Refrigerant leakage and capillary system blockage
Refrigerant (freon) is a working fluid that circulates through tubes, taking heat from the chambers. If a microcrack has formed in the circuit (often due to corrosion or mechanical damage during transportation), the gas gradually evaporates. As a result the refrigerator works, but does not freezesince the amount of gas is not enough for effective heat exchange.
Signs of a leak: the compressor runs continuously without turning off, the back wall (or evaporator) is warm or slightly warm, not cold. In models No Frost gurgling or hissing may be heard in the tubes.
Another common problem is a clogged capillary tube. Oil circulates in the system, which over time can thicken or mix with breakdown products, forming a plug. Freon cannot pass through the narrow cross-section, circulation stops, and cold ceases to be produced.
⚠️ Attention: Self-filling the refrigerator with freon is impossible without specialized equipment (vacuum pump, pressure gauge station). Attempts to “pump up” gas can lead to an explosive situation or complete failure of the compressor.
Solving these problems requires calling a specialist who will find the leak, seal it, replace the filter drier and fill the system with the required amount of refrigerant.
Malfunctions of the defrosting system (for No. Frost)
In refrigerators with a system No Frost ice does not form on food, but it accumulates on the hidden evaporator. Periodically (usually once every 8-12 hours) the heating element (heating element) is turned on, which melts the ice and water flows into the pan. If this cycle is disrupted, the evaporator becomes overgrown with a “fur coat” that blocks air circulation.
The fan that drives cold air through the chambers begins to rest against an ice block or stops altogether. As a result, the freezer may be cold, but the refrigerator compartment may be warm. Or the cold does not enter any of the chambers.
The main culprits of defrost system failure:
- ❄️ The evaporator heating element has burned out - there is simply nothing to melt the ice.
- ❄️ The defrost sensor is faulty - it does not give a command to turn on the heater or, conversely, does not turn it off on time.
- ❄️ The timer or control module has failed - the “brain” of the system does not start the defrosting cycle.
You can diagnose the problem by completely defrosting the refrigerator (turn it off for 24 hours with the doors open). If after turning it on it works normally, but after a couple of days the problem returns, it means that the defrosting system is faulty and requires replacement of components.
When professional repairs are needed
Despite the desire to save money, there are situations when self-repair is not only useless, but also dangerous. If you have checked all the simple reasons (power supply, settings, door tightness), and the refrigerator still does not cool, most likely, professional intervention is required.
This is especially true in cases where opening a sealed circuit is required. Modern refrigerators often use mixtures of gases that require precise dosage, and also have complex electronic control boards that can be burned if incorrectly diagnosed.
In addition, it is worth considering the age of the equipment. If your refrigerator is more than 10-12 years old, and it has a breakdown in the circuit or the compressor has burned out, the cost of repairs can be up to 70% of the price of a new unit. In such cases, it is often more profitable to purchase a new model with a guarantee and a modern energy efficiency class.
Frequently asked questions (FAQ)
Why does the refrigerator hum, but not is it freezing?
A humming sound means that the motor is trying to work, but the cooling cycle is not happening. Most often, this indicates a freon leak, a clogged capillary system, or a malfunction of the start relay, which prevents the compressor from reaching operating mode.
Can a refrigerator stop freezing due to a power surge?
Yes, voltage surges can damage the electronic control board or burn the compressor windings. In some cases, only the start relay burns out, which is a repairable case.
How long does it take for a refrigerator to reach operating temperature after defrosting?
Usually an empty refrigerator takes 2 to 4 hours to reach operating temperature. If you loaded it with products immediately, the process may take up to 8-12 hours. If during this time the cold does not appear, look for a malfunction.
What to do if it is cold in the freezer, but warm in the refrigerator compartment?
In systems No Frost this often indicates icing of the air ducts or a breakdown of the fan. In single-compressor models with a drip system, the problem may be a freon leak (it does not reach the upper compartments) or a malfunction of the damper.