Finding the location of refrigerator evaporator tubeoften becomes the first priority when detecting cooling problems or visible traces of oil on the inner walls of the chamber. The evaporator is the heart of the system, where the refrigerant boils and absorbs heat, but in modern models it is rarely visible right away. The design of units is constantly changing, and manufacturers are increasingly hiding key components behind decorative panels or integrating them directly into the housing.
Understanding the location of this element is critical for diagnosing freon leaks, which are the most common cause of equipment failure. If you notice that the refrigerator is humming but not cooling, or oily stains have appeared on the back wall, it means that the tightness of the circuit is broken. In most cases, it is the aluminum tube or the places of its connections that are damaged, so knowing its exact location will allow you to save time on disassembly.
In this article we will analyze in detail where to look for the evaporator in various types of refrigerators, from old Soviet models to modern systems. No Frost. You will learn what tools are needed to access the assembly and how to safely perform a visual inspection without the risk of damaging fragile system elements. Remember that careless handling of tubes can turn a minor repair into an expensive replacement of the entire circuit.
The principle of operation and design of the evaporator
To understand where to look for the tube, you need to briefly understand the physics of the process. The evaporator is a coil or panel, inside which liquid freon transitions into a gaseous state. This process is accompanied by active absorption of heat from the interior of the refrigerator or freezer. Depending on the design, the tube can be open or foamed inside the walls of the housing.
In classic single-compressor models, the refrigerant passes through the capillary tube and enters the evaporator, where its pressure drops sharply. This is where cooling occurs. It is important to note that the tube material is most often aluminum or steel, which makes it vulnerable to corrosion and mechanical damage if defrosted carelessly with a knife.
Why are tubes made of aluminum?
Aluminum has excellent thermal conductivity and is easy to process, which allows you to create complex shapes of coils. However, it is soft and easily pierced by sharp objects, unlike its steel counterparts, which are stronger, but conduct heat worse and are more difficult to solder.
Modern cooling systems often use a hidden evaporator. In such cases, the tube is mounted into the back wall of the chamber and filled with polyurethane foam. This increases energy efficiency, since the cold is evenly distributed over the entire surface, but makes repair almost impossible without compromising the integrity of the case.
Location in refrigerators with manual defrosting
In older models and budget refrigerators with manual defrosting, it is easier to find the evaporator tube everything. It is usually an open coil located at the top of the freezer compartment. You will see it immediately when you open the freezer door: it is a ribbed plate or a curved tube, often covered with a layer of frost during operation.
In some modifications, for example, in the brand technique Biryusa or old Atlantakh, the evaporator can be made in the form of a metal shelf inside freezer. The tube in this case is attached to the underside of the shelf. When defrosting such models, it is strictly forbidden to use sharp objects to chip ice, since the risk of damaging the thin wall of the tube is extremely high.
- 🧊 Open coil on the ceiling of the freezer.
- ❄️ Aluminum shelf plate inside the freezer.
- 🔩 Tubular evaporator mounted on the back wall.
Access to the tube in such models does not require disassembling the case. However, if you plan to look for a leak, pay attention to where the tube enters the body and the welds. This is where microcracks most often occur due to thermal expansion of the metal during cycles of turning the compressor on and off.
Where to look for the evaporator in a No Frost system
The situation changes dramatically when it comes to systems No Frost (or Full No Frost). In such refrigerators, the open evaporator is placed out of sight so as not to interfere with air circulation and not to occupy the useful volume of the chambers. It is hidden behind the rear plastic panel in the freezer compartment, and sometimes in the refrigerator compartment if the model is double-circuit.
To access the tube, you will have to remove the back wall of the freezer. Under the plastic you will find a compact heat exchanger consisting of many curved aluminum tubes with plates (fins) mounted on them. The air is driven through this radiator by a fan, cooled and distributed among the chambers through special channels.
It is important to understand that in the No Frost system the evaporator tubes are located very tightly. Any deformation of the fins or damage to the tube during cleaning may lead to disruption of air exchange or gas leakage. Often leaks in such models occur at soldering points or at the bends of tubes hidden deep in the bowels of the unit.
It is worth noting that in dual-circuit systems No Frost there may be two evaporators: one main one in the freezer and a second, smaller one, in the refrigerator compartment (often hidden behind a panel or at the top of the chamber). Troubleshooting in this case requires checking both circuits.
Hidden evaporator: foamed circuits
Refrigerators with a hidden, or foamed, evaporator are the most difficult to diagnose. In such models, the tube is mounted directly into the side or rear walls of the housing and filled with heat-insulating foam. Visually, you will not see it anywhere inside the chamber - the wall will be smooth, metal or plastic.
This technology is used in many modern models of brands Indesit, Ariston and others to improve aesthetics and increase useful volume. However, the reliability of such circuits is often lower than that of open analogues. Corrosion of metal under the influence of condensate, which accumulates between the tube and the wall, leads to fistulas.
If you have just such a refrigerator, then finding the location of the leak turns into a detective investigation. Often a problem is indicated by swelling of the side wall or the appearance of rust spots on the outside of the case. There may be no internal signs until the cold completely disappears.
Is it possible to restore a foamed evaporator?
Theoretically, it is possible to cut out part of the wall, but in practice this violates thermal insulation and aesthetics. Craftsmen often suggest installing an external evaporator (Kuganov) inside the chamber, which looks unaesthetic, but brings the refrigerator back to life.
Diagnostics of hidden leaks requires special equipment, such as a leak detector or an ultraviolet lamp (if fluorescent paint has been added to the system). It is almost impossible to independently find a hole in a foamed circuit without instruments; you can only assume its presence based on indirect signs.
Fault diagnosis and leak detection
Before you start disassembling and searching for the tube, you need to make sure that the problem lies precisely in a leak or damage to the evaporator. There are a number of symptoms that are highly likely to indicate this malfunction. Ignoring them can lead to the compressor burning out.
The first sign is the compressor running without stopping. The unit hums, trying to gain temperature, but there is no cold. The second sign is the absence of a characteristic gurgling or hissing sound when the engine stops, which indicates an empty circuit. Also pay attention to the condenser (grid at the back): if it is cold or warm only at the beginning, it means there is little or no freon in the system.
| Symptom | Probable cause | Location of the test |
|---|---|---|
| The refrigerator is not freezing, the compressor hot | Freon leakage | Soldering points, entrance to the housing |
| Oily spots inside the chamber | Depressurization of the evaporator | Around the evaporator tube |
| Frost only at the tube inlet | Clogging or leakage | Beginning of the coil |
| Side wall swelling | Corrosion of the hidden circuit | Side wall of the housing |
You can use a soap solution to search for leaks. Apply it to suspicious areas of the tubes (entry into the housing, welds, open areas of the coil). If an inflating bubble appears, it means that the gas is coming out there. In the case of foamed models, this method is ineffective, since the soap will not reach the hidden hole.
☑️ Diagnosis of leakage
Remember that the oil flowing out along with freon has a specific smell and consistency. It does not evaporate and remains sticky. Finding such stains on the bottom of the refrigerator or on the shelves is a sure sign that evaporator tube the evaporator tube is broken
Replacing and repairing the evaporator with your own hands
Repairing the evaporator is a task for experienced craftsmen, requiring special tools: torch, solder, vacuum pump and filling equipment. If you do not have these skills, it is better to limit yourself to visual diagnostics. However, if the determination is great, the algorithm of actions for open systems is as follows.
First you need to completely defrost the refrigerator and remove the old evaporator. To do this, the capillary tube and suction pipe are sealed off. The new evaporator is selected according to size and cooling capacity. Universal evaporators often have a long tube, which is carefully laid in a snake, being careful not to bend it.
⚠️ Attention: Before soldering new connections, be sure to flush the system with nitrogen. The entry of moisture or debris into the circuit will lead to instant failure of the new compressor or blockage of the capillary tube.
After installing the new unit, the system is sealed, evacuated (air and moisture are removed) and charged with freon of a strictly defined brand and weight indicated on the compressor nameplate. Overfilling or underfilling will lead to incorrect operation.
In the case of foamed evaporators, repairs are often replaced by installing a mounted evaporator (“crying” or "freezer") inside the chamber. This is less aesthetically pleasing, but allows you to restore the functionality of the refrigerator without complex cutting of foam blocks and damaging the factory thermal insulation.
Frequently asked questions (FAQ)
Is it possible to seal a hole in the evaporator tube with ordinary glue?
No, ordinary glue will not withstand pressure freon and low temperatures. Repairs require special brazing. Temporary measures, such as cold welding, can help deliver the refrigerator to service, but will not last long.
How much does it cost to replace the evaporator in the service?
The price depends on the model of the refrigerator and the type of evaporator (open or foamed). Replacing an open evaporator is cheaper because it requires less work. Repairing a foamed circuit can cost up to 70% of the price of a new refrigerator.
Why does the refrigerator freeze poorly after replacing the evaporator?
Possible reasons: poor-quality evacuation of the system (moisture remains), incorrect refilling with freon, or use of the wrong refrigerant. There may also be a blockage in the filter-drier.
How often should you defrost a refrigerator with an open evaporator?
It is recommended to defrost when an ice coat of more than 5 mm thick forms. This usually happens once every 4-6 months, depending on the humidity of the products and the frequency of opening the doors.
Is it dangerous to breathe freon vapors if there is a leak?
Modern refrigerants (R600a, R134a) in small quantities contained in household refrigerators are not toxic to humans after short-term contact. However, R600a (isobutane) is explosive when concentrated in air, so in case of a strong leak, it is necessary to ventilate the room and exclude sources of sparks.