Failure of the cooling system is one of the most serious problems that the owner of household appliances may encounter. If you notice that the refrigerator stopped freezingbut the compressor continues to hum, or a layer of ice has appeared on the back wall of the chamber where it should not be, there is a high probability of damage to the evaporator. This element is the heart of the refrigeration circuit, and its replacement requires not only technical skills, but also strict adherence to safety measures.
Replacing the evaporator yourself is a difficult task, since it involves working with the refrigerant and sealing the system. Errors at the soldering or vacuum stage can lead to repeated failure of the equipment. However, having the necessary tools and a theoretical basis, you can restore the unit’s functionality, avoiding an expensive visit from a technician. It is important to understand that the process requires care, because aluminum tubes it is easy to damage.
Before proceeding with disassembly, it is necessary to clearly determine the type of malfunction. Often, symptoms indicating a breakdown of the evaporator are confused with a thermostat failure or a clogged capillary tube. In this article, we will analyze in detail the algorithm of actions that will help you make an informed decision and, if possible, carry out repairs efficiently. Remember that safety and compliance with technology are the main priorities.
Diagnostics of evaporator faults
The first step in any repair is correct diagnosis. Evaporator is a radiator located inside the freezer or refrigerator compartment through which refrigerant circulates. If it is damaged, freon evaporates and cold production ceases. One of the obvious signs of a breakdown is the appearance of a characteristic hissing sound when the door is opened or the presence of oily spots where the tubes are damaged.
Visual inspection should be carried out in good lighting. Pay attention to the condition of the back wall of the camera. If you find plastic swelling, corrosion, or obvious holes in the aluminum fins, the diagnosis is confirmed. It is also worth listening to the operation of the compressor: if it turns on for a short time and turns off, the thermal relay may be triggered due to the lack of freon in the system.
⚠️ Attention: Never try to seal the hole in the evaporator with cold welding or sealant without completely pumping out the system and subsequent vacuumization. This is a temporary measure that often leads to moisture entering the circuit and combustion of the compressor.
To pinpoint the location of the leak, professionals use leak detectors, but at home you can rely on visual signs and a soap solution (although the latter method is risky due to moisture). If the damage is found in an accessible location, such as on a visible part of the tube, repairs can be made locally. However, most often a complete replacement of the unitis required, especially if corrosion has grown over a large area.
Necessary tools and materials
The quality of the repair directly depends on the preparation. To replace the evaporator, you will need a specialized tool, which is not always available to a home craftsman. The basic set includes a soldering torch (propane-oxygen or flux), a set of flarers, a pipe cutter and a vacuum pump. Without the last element, filling the system with refrigerant is impossible.
Particular attention should be paid to choosing a new evaporator. It must match the dimensions of the old one and have a similar heat transfer area. Often universal models are used that can be adjusted to fit the location. You will also need copper tubes for connections, solder and flux. The use of low-quality materials can lead to repeated depressurization in a short time.
Below is a table with an approximate list of tools and their purposes, so that you can assess your capabilities before starting work:
| Tool/Material | Purpose | Importance |
|---|---|---|
| Vacuum pump | Removing moisture and air from the circuit | Critical importance |
| Torch and solder | Soldering copper connections | Required |
| Pipe cutter | Even cut of copper tubes | High |
| Gauge manifold | Pressure control at refueling | Required |
Don't forget to prepare personal protective equipment. Working with open flames and chemicals requires caution. Gloves and safety glasses will protect your hands and eyes from flux splashes and sharp aluminum edges. Also have a fire extinguisher on hand just in case.
Preparing the refrigerator for repair
Before starting any work, the refrigerator must be completely defrosted. Even if there appears to be no ice, moisture may be hiding in the insulating materials. Unplug the appliance and leave the doors open for at least 24 hours. This is a critical step, since the presence of moisture in the system during soldering will lead to the formation of ice plugs and acidic compounds.
After defrosting, provide access to the rear wall of the refrigerator compartment. In some models, for example Indesit or Atlant, the evaporator is foamed into the housing. In this case, replacement requires careful opening of the back panel or, in difficult cases, partial destruction of the foam insulation. Assess the scale of the work in advance: if the evaporator is built into the housing, it may be easier to install an external (mounted) analogue.
☑️ Preparation for dismantling
Remove all shelves, drawers and fixtures that interfere with access to the rear wall. If the model allows, remove the inner plastic panel. Be careful with plastic latches - they become brittle in the cold. If you plan to cut into a foamed evaporator, determine the cutting lines in advance so as not to damage other communications.
Removing the old evaporator
The process of removing the old unit begins with disconnecting the copper tubes from the compressor and filter drier. Before soldering or cutting pipes, it is necessary to bleed off any remaining refrigerant. This should be done in a well-ventilated area, as the gas can be heavier than air and displace oxygen. After bleeding, the tubes are cut and the old evaporator is removed.
If the evaporator is foamed, it is carefully cut out or knocked out, trying to minimize damage to the insulation. The inner walls of the chamber are cleaned of glue and foam residues. When installing a new evaporator, especially a wall mounted evaporator, it is important to ensure tight contact with the back wall for efficient heat transfer. Often, aluminum tape or special clamping strips are used for this.
When removing the old assembly, additional problems may be discovered, such as corrosion of other elements or damage to the wiring. Carefully inspect the vacated space. If you find traces of oil far from the evaporator, this may indicate microcracks in other parts of the circuit, which will also require attention. Tightness is the key word at this stage.
⚠️ Attention: When dismantling foamed evaporators, do not use open flame for burning foam. This may cause the insulation to burn or damage the plastic parts of the housing. Use a mechanical removal method.
Installing and soldering a new unit
Installing a new evaporator requires precision. If you are using a wall-hung option, place it evenly along the back wall. Secure the tubes so that they do not bend or touch sharp edges. The spacing between turns must comply with the manufacturer's recommendations. To improve heat transfer, you can apply a thin layer of thermal paste or use aluminum tape.
The most critical point is soldering the connections. Copper tubes are connected to aluminum tubes through special adapters or steel inserts, since it is difficult to solder these metals directly. Use high-quality flux and solder with a melting point above 600 degrees. Heat the connection evenly, avoiding overheating, which can lead to burning through the thin walls of the tubes.
Nuances of soldering aluminum
Aluminum quickly oxidizes, so soldering must be carried out quickly and using active flux. It is important not to overheat the joint, otherwise the aluminum will simply spread without forming a high-quality seam. Before soldering, clean the surface to a shine.
After soldering all connections, the system is checked for leaks with nitrogen. The pressure rises to the operating value (usually 10-15 atmospheres) and is left for several hours. If the pressure gauge shows a drop in pressure, there is a leak somewhere that needs to be found and fixed. Only after a successful check is the system evacuated.
Evacuation and charging with refrigerant
Evacuation is the process of removing air and moisture from contour. The moisture remaining in the system freezes in the capillary tube, blocking the circulation of freon, which leads to incorrect operation. Connect the vacuum pump to the service connection and turn it on. The process must last at least 30-40 minutes to achieve a deep vacuum.
After evacuation, refrigerant is charged. The type of refrigerant (R134a, R600a) and its quantity are indicated on the label located on the rear wall of the refrigerator. Charging is carried out in the liquid or gaseous phase, depending on the type of refrigerant, with the compressor running. Monitor the pressure using the pressure gauge and the current consumption of the compressor.
The final step is to seal the service pipe. Clamp the tube with a clamp, solder the pinched area and cut off the excess. Check the soldering area with soapy water for bubbles. Plug in the refrigerator and leave it running without load for several hours, monitoring the temperature in the chambers and the operation of the automation.
Frequently asked questions (FAQ)
Is it possible to replace the evaporator without a vacuum pump?
Theoretically, some craftsmen use the method of “squeezing out” the air with the refrigerant itself, but this is highly not recommended. Moisture and air remain in the system, which leads to the formation of ice plugs, increased pressure and rapid wear of the compressor. For long-term repairs, a vacuum pump is required.
What is the difference between a mounted evaporator and a foamed one?
The foamed evaporator is integrated into the refrigerator body and hidden under insulation. A mounted one is a separate aluminum radiator that is mounted on the back wall inside the chamber. Replacing the foam with a hinged one is a common repair practice that simplifies maintenance in the future.
How long does it take to replace an evaporator?
For an experienced technician, the process takes from 2 to 4 hours, including time for vacuuming and checking the tightness. For a beginner, taking into account preparation and study of instructions, the time can increase to 6-8 hours. It is important not to rush at the soldering stage.
Why does the refrigerator not freeze after replacing the evaporator?
There may be several reasons: insufficient amount of refrigerant, the presence of an air lock in the system, a clogged capillary tube or poor-quality soldering (leakage). It is also worth checking the operation of the thermostat and the tightness of the new evaporator to the chamber wall.