When household appliances ceases to perform its main function, the owner is faced with the question: which part of the refrigerator that freezes has failed? Understanding the basic principles of operation of the unit helps not only in choosing a new model, but also in proper operation of the existing one. The refrigerator compartment is a complex mechanism where each element plays a critical role in maintaining low temperatures.
The main task of the cooling system is the continuous circulation of refrigerant, which takes heat from the internal volume and releases it to the external environment. This process occurs due to the coordinated work of several key nodes. If one of them stops functioning correctly, the products begin to deteriorate, and unwanted ice or, conversely, water appears on the walls.
In this article we will analyze in detail the design of the refrigeration circuit, consider the differences between the drip system and No Frost, and also learn how to diagnose typical breakdowns. You will learn why it is important to keep the condenser clean and how often you need to defrost the old-style unit. A deep dive into technical details will allow you to extend the life of your equipment.
The principle of operation of the refrigeration circuit
The heart of any refrigeration equipment is the compressor, which is often called a motor. It is this that creates the pressure necessary for the movement of freon through the tubes. Without this component, refrigerant circulation would not be possible and heat exchange would not occur. Modern models can be equipped with one or two compressors, which affects energy efficiency and noise levels.
After compression, freon gas enters the condenser, usually located on the rear wall. Here the substance cools and turns into liquid, releasing the accumulated heat into the kitchen atmosphere. This process is accompanied by heating of the grate, which is an absolutely normal physical phenomenon. It is important to ensure free flow of air to the rear panel of the device.
The refrigerant then passes through the capillary tube and enters the evaporator. It is in this unit that a sharp expansion of gas and absorption of heat from the refrigerator chambers occurs. Evaporator - this is the very part that directly cools the products. The temperature inside the evaporator tubes can drop to minus 20-30 degrees, depending on the thermostat settings.
After passing through the evaporator, the freon returns to the compressor and the cycle repeats. Violation of the tightness of any part of this circuit leads to gas leakage and cessation of cooling. Therefore, if you find oily stains on the floor or back wall, you should immediately call a specialist.
Evaporator: main cooler of the chamber
The evaporator is a system of tubes or plates located inside or behind the walls of the refrigerator and freezer chambers. In models with an open evaporator (usually in the freezer), it is covered with a layer of frost, which is periodically removed. In more modern systems, this element is hidden behind a plastic panel.
The manufacturing material is most often aluminum or steel with an anti-corrosion coating. Aluminum has excellent thermal conductivity, but is susceptible to mechanical damage. Piercing the evaporator wall with a knife while chipping ice is a sure way to damage the refrigerator forever.
Two-chamber models often use one evaporator located in the freezer compartment. Cold air from it is redistributed into the fridge compartment using fans or natural convection. If the fan stops, the temperature in the upper compartment rises, although the freezer continues to work.
Why can’t you clean off the ice with a knife?
Puncture of the evaporator tubes leads to an instant release of freon and moisture entering the system. Repair in this case requires expensive replacement of the evaporator and refilling, which is often not economically feasible.
The efficiency of the evaporator directly depends on the cleanliness of its surface. A layer of ice more than 5 mm thick significantly impairs heat transfer, forcing the compressor to wear out. Regular defrosting helps maintain energy efficiency at a high level.
Differences between drip system and No Frost
Moisture removal technology is a key factor that distinguishes different types of refrigerators. In a drip system (a "crying" evaporator), moisture condenses on the back wall of the refrigerator compartment, freezes, and then flows into the drain hole when the compressor is turned off. This is a simple and quiet mechanism that does not require complex electronics.
The system No Frost ("without frost") works differently. Here the evaporator is hidden and equipped with a fan that drives dry cold air throughout the entire volume of the chambers. The moisture settles on a hidden evaporator, where it is automatically thawed by a heating element (heating element) at specified intervals. The user does not need to defrost such a refrigerator manually.
Each of the systems has its own advantages and disadvantages. The drip method better preserves the natural moisture of food, but requires manual defrosting of the freezer. No Frost gets rid of ice completely, but can slightly dry out food if they are not packaged.
In combined models, the refrigerator compartment is equipped with a drip system, and the freezer is equipped with No Frost. This allows you to combine comfort of use and optimal storage conditions for vegetables and fruits. When choosing, you should take into account the climatic conditions of the room and the frequency of opening the doors.
Diagnostics of cooling system faults
Understanding which part of the refrigerator is freezing helps to quickly identify the problem. If the compressor hums, but there is no cold, there may be a freon leak or a blockage in the capillary tube. In this case, professional diagnostics using pressure gauges are required.
If the freezer is working and the refrigerator compartment is warm, the problem may lie in a malfunction of the fan or a clogged air flow channel. It is also worth checking the thermostat settings. Sometimes users accidentally switch the equipment to the “holiday” or minimum cooling mode.
A lot of ice in one corner of the freezer may indicate a leak in the door seal. Warm, moist air enters through the gap and instantly freezes. Replacing rubber is a simple procedure that you can do yourself.
☑️ Primary diagnostics
Extraneous noise, knocking or vibration often indicate problems with the compressor fastening or foreign objects getting under the equipment. If the noise is accompanied by a cessation of cooling, this is a serious signal that the motor or start relay is broken.
Table of main elements and their functions
To systematize knowledge about the structure of the refrigerator, it is useful to refer to the summary table. It will help you quickly navigate the names of parts and their purposes when reading instructions or communicating with a technician.
| Element | Location | Main function | Typical malfunction |
|---|---|---|---|
| Compressor | Bottom, rear | Freon compression and circulation | Knocking, overheating, startup failure |
| Condenser | Rear grid | Gas cooling and liquefaction | Dust contamination, corrosion |
| Evaporator | Inside chambers / behind the wall | Direct cooling | Icing, mechanical breakdown |
| Thermoregulator | Inside the chamber / outside | Temperature control | Incorrect readings, sticking |
Knowledge of the functions of these elements allows you to more accurately describe the symptoms of a breakdown when calling a specialist. For example, the phrase “the compressor runs constantly without turning off” gives the technician more information than simply “the refrigerator does not freeze.”
It is worth noting that in modern inverter models the compressor does not turn off completely, but only changes the operating power. This is a normal mode aimed at saving energy and maintaining a stable temperature.
Care and extending service life
In order for the part of the refrigerator that freezes to serve for a long time, you must follow the operating rules. Regular cleaning of the inner chamber with a weak soda solution helps remove odors and bacteria. Do not use abrasive powders, they can damage the plastic and coating.
It is recommended to vacuum or gently brush the outer condenser grill once every six months. The dust layer acts as a heat insulator, interfering with heat transfer, which leads to overload of the compressor. This is one of the most common reasons for premature failure of equipment.
⚠️ Attention: Never use sharp metal objects to chip ice. The risk of damaging the evaporator and releasing all the refrigerant is 99%.
Check the integrity of the sealing rubber on the doors. If it is cracked or comes off, the cold will go away and the compressor will run idle. Wiping the rubber with silicone grease preserves its elasticity.
Do not place hot foods inside the chamber. This puts excess stress on the cooling system and leads to the formation of excess moisture. Allow food to cool to room temperature before loading.
Frequently asked questions (FAQ)
Why is the back of the refrigerator covered in ice?
This could be a sign of a faulty thermostat that is preventing the compressor from turning off, or a problem with the door seal. In drip systems, short-term ice formation is part of the operating cycle.
How often do you need to defrost a No Frost refrigerator?
The No Frost system does not require defrosting to remove ice, but once a year it is recommended to turn off the equipment for hygienic washing and drying of hidden ventilation channels.
Is it possible to replace the evaporator on your own?
Theoretically it is possible, but this requires evacuation of the system, soldering of tubes and precise charging of freon. Without special equipment and skills, such a replacement is impossible.
What to do if there is water in the refrigerator, but it freezes?
Most likely, the drainage hole for draining melt water is clogged. It can be carefully cleaned with a special soft wire or a brush included in the kit.
Does the amount of food affect the operation of the freezer?
Yes, a completely empty refrigerator works less efficiently. Products serve as cold accumulators. However, you shouldn’t overcrowd the chamber either - the air should circulate freely.