The situation when the refrigerator does not cool welloften takes you by surprise, threatening the safety of food. Owners of household appliances may experience that the temperature in the main chamber is higher than normal, and the ice is melting in the freezer compartment. This does not always mean the breakdown of expensive components. Sometimes the problem lies in a banal violation of operating rules or a minor malfunction that is easy to fix.
Before calling a technician, it is necessary to carry out an initial diagnosis. It is important to understand whether the compressor is working at all, whether there is any extraneous noise and how long ago the problem appeared. In some cases, the unit simply requires defrosting, and in others, replacement thermostat or compressor. Correctly identifying the symptom will save time and money.
In this article we will analyze in detail the main reasons for the decrease in the performance of the refrigeration unit. We will consider both external factors and internal breakdowns of the system No Frost or drip defrosting. Understanding the principles of operation will help you quickly find the source of the malfunction.
Violation of operating rules and external factors
Often the reason that The refrigerator does not freeze welllies not in a technical malfunction, but in user errors. The most common of them is a violation of the temperature regime in the room. If the unit is installed next to a radiator, stove, or in direct sunlight, the cooling system cannot cope with the heat flow. The compressor is working hard, but cannot reach the desired temperature.
The condition of the sealing rubber on the doors is also critically important. If seal has become dry, dirty or deformed, warm air constantly enters the chamber. This leads to the formation of a “fur coat” on the evaporator and an increase in the temperature inside. Check the tightness of the door with a sheet of paper: if it easily pulls out when the door is closed, the tightness is broken.
Do not forget about loading the chambers. Shelves filled to capacity with products block the circulation of cold air. This is especially true for models with a No Frostsystem, where air flows should freely wash the evaporator and be distributed throughout the volume. An overloaded refrigerator will work inefficiently, creating “warm” zones.
⚠️ Attention: Do not install the refrigerator close to the wall. The gap between the rear grille of the condenser and the wall should be at least 10-15 cm for normal ventilation.
Problems with the thermostat and temperature sensors
One of the key parts that controls the cycle of turning the motor on and off is thermostat (thermostat). It is he who “tells” the compressor when to start cooling and when to stop. If the contacts inside the thermostat are oxidized or the mechanism is jammed, the compressor may not turn on at all or work in too short cycles, not having time to freeze the chamber.
In modern models with electronic control, the function of a mechanical thermostat is performed temperature sensors (thermistors). Their resistance changes depending on heat. If the sensor “lies” and shows the control unit that it is already -10°C in the chamber, although it is +5°C there, the compressor simply will not start. Diagnosis of such malfunctions requires a multimeter to check the continuity of the circuit.
Symptoms of a malfunctioning thermostat often manifest themselves in the fact that the refrigerator either does not turn on at all or works nonstop, trying to achieve an unattainable goal. In mechanical models, a sign of failure may be the absence of a characteristic click when turning the control knob. Replacing this part usually does not require sophisticated equipment and is accessible to a DIYer.
It is important to note that in two-compressor refrigerators, each chamber has its own control circuit. If only one compartment cools poorly, and the second one works normally, the problem is localized precisely in the control circuit or freon pipe of this circuit.
Faults of the compressor and start relay
The heart of any refrigeration machine is compressor. If it is faulty, the refrigerant will not circulate through the system. However, often the motor itself is intact, and the problem lies in the start-up relay. This device provides an impulse to start the engine and protects it from overloads. If the relay is burned out, you will hear a click, an attempt to start and a click again - the motor will hum, but will not start.
There are three main types of compressors found in household appliances: conventional, inverter and linear. Inverter compressor works smoothly, regulating power, and rarely turns off completely. Its diagnosis is more difficult, since it does not make characteristic clicks when starting. Linear models, popular in the brand LGcan make a knocking noise during operation, which is sometimes normal, but can also indicate a breakdown.
If the compressor is hot to the touch, but does not start, this may indicate an interturn short circuit in the windings or piston group wedge. In this case, a professional replacement of the unit is required. Self-repair of the compressor at home is impossible due to the need to evacuate the system and refill with freon.
What is a compressor “wedge”?
A compressor wedge occurs when the mechanical parts inside the motor get stuck due to lack of lubrication or foreign objects. The motor hums, consumes high current, but the shaft does not rotate. Often in such cases, the starting relay burns out, taking the blow.
You can check the serviceability of the starting relay visually (carbon deposits, melting) or by replacing it with a known good one. This is one of the most common reasons why the refrigerator has stopped freezing suddenly, without preliminary symptoms.
Refrigerant leakage and system blockage
Refrigerant (freon) is a working fluid that transfers heat. In a working system, it circulates in a closed loop for years. However, if it occurs freon leak, the cooling efficiency decreases. First, the refrigerator starts working longer, then stops turning off, and eventually stops cooling completely. The cause of the leak may be corrosion of the evaporator (especially in older models with “crying” type aluminum tubes) or mechanical damage.
Another common problem is clogging of the capillary tube. Oil circulates in the system, which over time can thicken or form a plug along with decomposition products. Also, moisture that has entered the circuit due to poor-quality filling may freeze in the tube. Symptom of blockage: the compressor runs constantly, but the condenser (grid at the back) is only partially warm or cold, and there may be frost in the area of the filter-drier.
Diagnostics of leaks and blockages requires special equipment: a pressure gauge station, a leak detector and a vacuum pump. The technician opens the system, purges it with nitrogen, changes the filter-drier and seals the leak. It is impossible to fix these faults on your own without tools.
⚠️ Attention: If you notice an oily stain under the refrigerator or on the back wall inside the chamber, this is a sure sign of depressurization of the system. Such a unit cannot be operated.
Failures in the No Frost system
Refrigerators with a system No Frost (without frost) eliminate manual defrosting, but add complexity to the design. Air circulates through an evaporator hidden behind a plastic panel in the freezer compartment. If this evaporator becomes covered with ice, the air flow is blocked and the cold stops flowing into the chambers. In this case, the compressor itself can work properly.
A timer (or electronic module) and a defrost sensor are responsible for the defrosting process of the evaporator. If the heating element burns out, the ice does not melt and builds up, blocking the fan. If the defrost sensor is faulty, it may not give a command to turn on the heating or, conversely, may not turn off the heating on time. The fan may also fail, ceasing to circulate cold air. Defrost heating element, timer (or electronic module) and defrost sensor. If the heating element burns out, the ice does not melt and builds up, blocking the fan. If the defrost sensor is faulty, it may not give a command to turn on the heating or, conversely, may not turn off the heating on time. The fan may also fail and stop moving cold air.
Users often encounter a situation where, after defrosting, the refrigerator starts working normally for 5-7 days, and then stops freezing again. This is a classic sign of a malfunction of the defrost system No Frost. Ice accumulates gradually until it completely clogs the channels.
☑️ Diagnostics of the No Frost system
To eliminate the malfunction, it is often necessary to completely defrost the unit during the day (at least 24 hours) with the doors open. This will allow the ice to melt and clear the drainage. If, after switching on, the problem repeats a week later, the burnt elements of the defrost circuit must be replaced.
Diagnostics and table of symptoms
To systematize knowledge, we present a table of the main symptoms and probable causes. This will help you get your bearings before calling a specialist. Remember that an accurate diagnosis can only be made by a specialist with equipment.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor does not turn on, there is no light | No power, the socket or cord is burnt out | Low |
| Buzzes, clicks, but does not start | Faulty starting relay or compressor wedge | Medium |
| Works without stops, it’s warm inside | Freon leak or capillary blockage | High (needs a technician) |
| Ice in the freezer, warm in the refrigerator | Malfunction of the defrost system (No Frost) | Average |
| Turns on and off frequently | The thermostat or sensor is faulty | Average |
When diagnosing, always pay attention to noise. A loud knocking, grinding or whistling noise may indicate a specific component. For example, a whistle is often caused by a freon leak, and a knock is a problem with the compressor suspension or fan.
When you need to call a specialist
Despite the desire to save money, there are situations when do-it-yourself repair not only will not help, but will also aggravate the situation. If the problem is related to a sealed circuit (leak, blockage, compressor replacement), professional intervention is required. Improper evacuation of the system will leave moisture in it, which in a short time will cause the new compressor to fail.
A master is also needed if replacement is required evaporator. In modern refrigerators, evaporators are often “foamed” into the body. Replacing them is a labor-intensive process that requires opening the back wall or installing an external “crying” evaporator. It is difficult to perform such work efficiently without experience.
If you are not confident in your abilities, it is better to entrust the equipment to professionals. Misdiagnosis can lead to the purchase of unnecessary parts. Always check with the specialist whether he provides a guarantee for the work performed and the spare parts used.
⚠️ Attention: Never try to break the ice in the freezer with a knife or sharp objects. One awkward movement can damage the evaporator tube, which will lead to an instant leak of freon and expensive repairs.
How much does the repair cost?
The cost depends on the model and the breakdown. Replacing the thermostat will cost the least. Freon refilling and leak detection are more expensive. Replacing the compressor is the most expensive part, often accounting for up to 50-70% of the cost of a new refrigerator.
Prevention and care of the refrigerator
In order for refrigerator to serve for a long time and not let you down, you need to take care of it. Regular defrosting (even for the No Frost system once a year for prevention) prolongs the life of the unit. Keep the condenser grill at the back clean: dust