Failure of the evaporator is one of the most unpleasant situations for the owner of household appliances, since this unit is directly responsible for generating cold. If frost has stopped forming on the back wall of the chamber, and the compressor hums without interruption, but the temperature inside does not drop, most likely there is a refrigerant leak through microcracks in the heat exchanger tubes. In this case, a dilemma arises: buy a new unit or try to restore the functionality of the old one.
Full replacement of the evaporator is often a more reliable solution than finding the leak and then sealing it, especially if the refrigerator has been in use for more than 7-10 years. The metal becomes thinner during this time, and it’s only a matter of time before a new hole appears next to the repaired one. However, this process is labor-intensive and requires not only plumbing skills, but also specialized equipment for working with refrigerants.
Before proceeding with dismantling, it is necessary to accurately determine the type of part being replaced, since the designs in modern Indesit, Atlant or Beko can differ radically. An error in choosing a model or a violation of installation technology will lead to repeated failure of the system in the shortest possible time. In this article we will analyze all stages of work, from diagnostics to the final check of the circuit tightness.
Diagnostics of the fault and selection of an analogue
The first step should always be a thorough visual and instrumental diagnosis. It is irrational to simply change an expensive component without confirming its malfunction. Users often confuse the failure of the evaporator with a broken thermostat or a clogged capillary tube. If you see swelling on the back wall of the freezer or hear the hissing of gas when punctured, the diagnosis is most likely correct.
When selecting spare parts, it is critical to consider not only the overall dimensions, but also the heat transfer area. Using the wrong equivalent will result in the compressor working overload, trying to compensate for the lack of cooling capacity. As a result, the life of the motor will be reduced significantly, and the products in the chamber will begin to deteriorate.
⚠️ Attention: Do not try to use universal evaporators made of aluminum to replace copper tubes in systems where this is not provided for by the design, without appropriate treatment of the contacts. Galvanic copper-aluminum couple in the presence of moisture causes rapid electrochemical corrosion, which will lead to a new leak in 6-12 months.
For an accurate selection, you will need to know the model of your refrigerator and, preferably, the serial number of the part. In some cases, for example, in old models ZIL or Minsk, it is impossible to find the original, and you have to remake the seat for a modern analogue. This requires caution when working with plastic panels and thermal insulation.
Required tools and materials
High-quality repairs are impossible without a specialized set of tools. A standard set of screwdrivers and pliers will not be enough here, since the work is carried out with non-ferrous metals and gas under pressure. The lack of necessary equipment often becomes the cause of defects that have to be redone, wasting time and money on freon.
The main tool for connecting copper tubes is a gas torch. Electric soldering irons are not suitable for this purpose, since they are not able to provide the required melting temperature of the solder and heating of the massive condenser tubes. You will also need a rolling kit if you decide to make connections through fittings, although professionals prefer soldering.
- 🔥 Gas burner with a cylinder (propane-butane or MAF).
- 🔧 Set of pipe cutters and rolling machines for copper pipes.
- 🌡️ Vacuum pump and pressure gauge station.
- 🧴 Flux (borax or specialized powder) and solder (silver or phosphorus).
Special attention should be paid to consumables. The use of low-grade solder with a high lead content makes the seam brittle and subject to vibration loads. Silver solder provides better fluidity and strength of the connection, which is critical for assemblies experiencing temperature changes. Also, do not forget to purchase a bottle of nitrogen to purify the system before soldering - this will prevent oxidation of copper from the inside.
Preparing the refrigerator for dismantling
Before starting active operations, it is necessary to completely empty the fridge compartment. All products, shelves and drawers must be removed. If there is ice left in the chamber, it must be defrosted naturally. Using a hairdryer or hot water to speed up the process may damage the plastic housing of the evaporator or lead to deformation of thin-walled tubes.
Next, access to the rear of the unit should be provided. In models with the system No Frost you will need to remove the rear panel of the freezer compartment, and in two-compressor models, you will also need to remove the refrigerator compartment panel. Be careful with fastening elements: the plastic on old refrigerators becomes fragile and easily breaks if handled carelessly.
☑️ Preparation for dismantling
An important step is pumping out the residual freon. Although careful puncture of the tube is often practiced at home, environmental and safety regulations require the use of a vacuum pump to collect the refrigerant. This is especially true if you plan to use an old compressor, which is sensitive to the cleanliness of the system.
The process of removing the old evaporator
Dismantling is the dirtiest and most time-consuming stage of the work. In most modern refrigerators, the evaporator is “embedded” in the back wall or pressed tightly against it. It is almost impossible to disconnect it without damaging the aluminum tubes, so most often you have to act radically. Carefully cut off the thermal insulation and release the fasteners.
If you are replacing a “crying” evaporator in the refrigerator compartment, you will need to disconnect it from the capillary tube and the compressor suction pipe. The soldering area must first be cleaned of paint and dirt. Heat the connection evenly, being careful not to overheat the compressor tube itself, so as not to damage the varnish insulation of the windings.
When working with sheet-type freezer evaporators, which are pressed into the housing, the cutting method is often used. The old sheet is cut along the perimeter, being careful not to touch the outer lining of the refrigerator. After removal, the remains of the old heat exchanger and polyurethane foam are thoroughly cleaned. The surface must be smooth and clean to ensure tight contact with the new element.
⚠️ Attention: When cutting out the old evaporator from the refrigerator wall, use only hand tools (knife, chisel). Using a grinder or jigsaw carries a high risk of damaging the outer casing or, even worse, nearby electrical wires or tubes of another circuit.
Installation of a new heat exchanger
Installation of a new unit requires precision. If you are using a mounted evaporator (an alternative to a built-in one), it must be pressed firmly against the back wall of the chamber. For this purpose, special staples, adhesive aluminum tapes or heat-resistant sealant are used. Gaps between the tubes and the wall are unacceptable, since air is an excellent heat insulator and operating efficiency will decrease.
Connection to the mains is carried out by soldering. First, the tube of the new evaporator is connected to the filter drier, then to the suction line of the compressor. It is important to ensure that the burner flame does not touch plastic elements or door seals. It is better to carry out the work with an assistant who will hold the parts and supply the tools.
After soldering all connections, it is necessary to pressurize the system with nitrogen. This will reveal microscopic fistulas that could have formed during installation. The pressure in the system is raised to 10-15 atmospheres and left for several hours (ideally for a day), monitoring the pressure gauge readings. A drop in pressure even by a division indicates a leak.
What to do if the new evaporator does not fit into place?
If the dimensions of the analogue differ from the original, you can carefully bend the tubes (only copper parts, aluminum parts cannot be bent!), changing the geometry of the coil. If the evaporator is larger, its edges can be bent or, in extreme cases, shortened by removing excess turns, but this will reduce the cooling area.
Evacuating and charging with refrigerant
The final stage is creating a vacuum in the system. This is necessary to remove air and, more importantly, moisture vapor. Moisture in the system is the main enemy, which, when frozen, forms an ice plug in the capillary, blocking the circulation of freon. Evacuation is carried out for at least 30 minutes until the pressure gauge needle freezes below zero.
Refilling is carried out strictly according to the weight indicated on the refrigerator's factory tag. Using cylinders without weights (“by eye”) is unacceptable. A lack of freon will lead to poor cold, and an excess will lead to increased pressure in the system, freezing of the compressor housing and possible rupture of the tubes. The type of refrigerant (R134a, R600a) must also strictly comply with the specification.
| Parameter | Standard value | Consequences of deviation |
|---|---|---|
| Vacuum pressure | < -1 bar (absolute) | Residual moisture, ice plug |
| Filling weight (R134a) | ± 5 grams from normal | Underheating or overheating of the compressor |
| Suction temperature | up to +15°C | Risk of water hammer in the compressor |
| Compressor current | Not higher than nominal | Combustion of the motor windings |
After refueling, turn on the refrigerator and allow it to operate for 2-3 hours. At this time, the temperature in the chambers and the heating of the compressor are monitored. If all parameters are normal and uniform frost forms on the evaporator, the replacement can be considered successful. The hole through which the soldering was carried out is carefully sealed or closed with a decorative plug.
Frequently asked questions (FAQ)
Is it possible to solder a hole in an aluminum evaporator?
Theoretically, it is possible using special two-component compounds (for example, “Cold”) or low temperature soldering. However, practice shows that such repairs rarely last more than a year. Aluminum does not solder well, and corrosion often occurs at the repair site. A complete replacement is more reliable.
How much does it cost to replace an evaporator in a service?
The price consists of the cost of the spare part (from 2000 to 6000 rubles) and the work of the technician (from 3000 to 8000 rubles). The total amount is often 50-70% of the cost of a new budget refrigerator, which makes self-repair economically feasible if you have the skills.
Why does the refrigerator freeze poorly after replacing the evaporator?
There may be several reasons: insufficient amount of freon, the presence of an air lock in the system, poor-quality vacuuming (residual moisture) or inconsistency the area of the new evaporator to the requirements of the model. It is also possible that the capillary became clogged when soldering without purging with nitrogen.
Is it necessary to change the filter drier when replacing the evaporator?
Yes, this is a mandatory requirement. The old filter is already saturated with moisture and oil breakdown products. Installing a new filter-drier ensures that the system is cleaned of possible contaminants and moisture that entered during installation.