A modern refrigerator is a complex unit, where compressor acts as the heart of the entire system. It is this that ensures the circulation of the refrigerant, creating the necessary cold in the chambers. When this unit fails, household appliances cease to perform their main function, and food begins to deteriorate. Owners are often faced with a dilemma: call a technician or try to do do-it-yourself repairs.
Independent motor replacement requires not only technical skills, but also specific tools. You will have to work with copper tubing, high temperatures and pressurized gas. If you decide to proceed without the involvement of service services, it is important to understand that the process includes not only mechanical installation of the part, but also sealing the system, as well as filling with freon. Errors at any stage can lead to final breakdown of the unit.
Before proceeding with dismantling, it is necessary to conduct a thorough diagnosis. Often, symptoms of a faulty compressor, such as no cooling or a loud hum, can indicate problems with the thermostat or start relay. Make sure that electrical circuit it is intact, and that the motor itself really requires replacement. Only after confirming the diagnosis should you prepare the tools and order a new spare part that is suitable specifically for your refrigerator model.
Diagnostics and preparation for repair
The first step is a visual and sound analysis of the operation of the refrigerator. If the unit hums but does not start, or starts for a few seconds and clicks when turning off, these are classic signs of a malfunction. motor-compressor. It is also worth checking the heating of the housing: if it is too hot or, conversely, remains cold when the engine is running, this is a cause for concern. Before any manipulations, be sure to disconnect the device from the power supply.
To carry out the work, you will need a specialized tool, without which a high-quality replacement is impossible. The usual DIY kit will not be enough here. It is critical to have access to the vacuum pump and gauge station as the system must be completely dry and sealed. Without removing moisture and air from the circuit refrigerant cannot work effectively.
- 🔧 Set of pipe cutters and rolling for working with copper lines.
- 🔥 Gas torch or special soldering iron for copper with solder.
- 📏 Manometric manifold for pressure control and evacuation.
- 🧤 Protective gloves and glasses for safety when working with gas.
It is important to choose a compressor with similar power and cooling performance characteristics. Using the wrong model may result in system overload or insufficient cooling. Pay attention to the type of refrigerant that was used previously - R134a or R600a, as they require different oils and charging procedures.
⚠️ Attention: Before starting work, make sure that there is good ventilation in the room. Refrigerants are heavier than air and can displace oxygen, creating a risk of suffocation in a confined space.
Removing the old compressor
The process of removing the old unit begins with gaining access to the rear technical niche of the refrigerator. Typically the compressor is covered with a metal or plastic casing. After removing the protection, you will see the motor itself, the capacitor and the tube system. The first step is to bleed off the remaining freon if the pressure in the system still remains. This is done by carefully filing the thinnest copper tube.
Next, you should disconnect the electrical contacts. Remove the protective plastic box on the compressor housing where the terminals are located. Disconnect the wires of the starting and protective relay, having previously photographed their location so that when installing a new unit you do not mix up the polarity. Often the wires stick or oxidize, so act carefully so as not to damage the insulation.
The most crucial moment is unsoldering the copper tubes. Use a gas torch to heat the connection between the fitting and the tube. When the solder has melted, carefully move the tube to the side. Do not apply excessive force to the compressor itself, so as not to break off the suction or discharge pipes, as their restoration is extremely difficult. After disconnecting all three tubes (two from the system and one sealed for the process), the compressor can be removed from the mounts.
☑️ Dismantling steps
Preparation of the new compressor and system
The new compressor is often supplied with plugs in the pipes, which prevent moisture and dust from getting inside. These plugs cannot be removed in advance. Just before soldering, remove them and quickly connect them to the system pipes. Air containing moisture should not get inside the engine, as this will lead to the formation of ice plugs and acid in the oil.
Before installing a new unit, it is recommended to flush the cooling system. When the old engine burned, combustion products and acidic residues could get into the pipes. Flushing is carried out with nitrogen under pressure. If this is not possible, the minimum that needs to be done is to blow out the circuit and replace the filter-drier, which is a mandatory element for any opening of the system.
The new compressor is installed in the standard mounting locations. Pay attention to the vibration mounts (rubber feet), they must be intact and correctly installed. This will reduce the noise level when the unit operates. Tighten the mounting bolts, but do not overtighten them, so as not to damage the threads or motor housing.
Why change the filter drier?
The filter drier is filled with zeolite, which absorbs moisture from the system. When the circuit is opened, the zeolite is instantly saturated with moisture from the air and loses its properties. If you do not replace the filter, moisture will freeze in the capillary tube, blocking the circulation of freon, and the refrigerator will stop freezing.
Soldering of connections and sealing
The quality of soldering determines the durability of the repair. Copper tubes must be connected to the compressor pipes and the process fitting for filling must be soldered. Use silver solder or special fluxed copper solder. The joint must be heated evenly so that the solder flows into the gap due to the capillary effect, and does not just stick on top.
It is important to follow the soldering sequence. First, the discharge tube (outlet from the compressor) is soldered, then the suction tube, and lastly the filling fitting is sealed. When soldering, make sure that the torch flame does not fall on other plastic elements or wire insulation located in the immediate vicinity.
After soldering all connections, it is necessary to check the system for leaks. This is done by supplying nitrogen or dry air under pressure (about 10-15 atmospheres). A soap solution is applied to all seams. If bubbles appear, there is a leak that needs to be repaired by re-soldering. Operating a leaking system is strictly prohibited.
| Connection type | Soldering temperature | Solder type | Features |
|---|---|---|---|
| Copper-Copper | ~700°C | Phosphorus | Does not require flux |
| Copper-Steel | ~800°C | Silver | Required flux |
| Aluminium | ~550°C | Special. alloy | Complex soldering |
Evacuation and refrigerant charging
After successful crimping, the vacuum stage begins. This is a critical procedure that cannot be ignored. The vacuum pump is connected to the system via a pressure gauge station. The pump must run for at least 30-40 minutes to remove all moisture and air from the circuit. The residual pressure should tend to zero. Moisture in the system is the main enemy of the refrigerator, leading to corrosion and blockage of the capillary.
The refrigerator is refilled strictly according to the weight indicated on the nameplate located inside or behind the unit. Using a freon cylinder and electronic scales is the only correct method. Filling by eye or by pressure often leads to incorrect operation. Different types of freon (R134a, R600a, R404a) require different weight standards.
The refueling process occurs while the compressor is running. Freon is released in small portions through the suction tube until the scales show the required value. After reaching the required weight, the process fitting is pinched and sealed. The pressure in the system will stabilize only after the refrigerator has been running for some time.
⚠️ Attention: Isobutane (R600a), used in many modern refrigerators, is an explosive gas. All work with it should be carried out in a well-ventilated area away from open flames and sparks.
Startup and performance check
After all work is completed and the soldering areas have cooled, you can turn on the refrigerator. The initial start-up may be accompanied by a characteristic sound of air escaping from the system if the evacuation was not carried out perfectly, but this is acceptable in small quantities. The main indicator of success is uniform heating of the condenser (grid at the back) and the appearance of cold in the chambers.
The check should be carried out within several hours. Pay attention to the operating cycle: the compressor must turn on, run for a certain time, turn off and turn on again. If the motor runs non-stop or turns off too quickly (clocking), the amount of freon may be selected incorrectly or the capillary is clogged.
It is also important to listen to the noise level. The new part may sound a little different, but there should be no extraneous knocking, rattling or vibration of the case. If all parameters are normal, the repair can be considered complete.
Is it possible to replace a compressor without soldering?
There are so-called “quick-release” couplings, but they are considered a temporary solution and do not provide adequate tightness for long-term operation. Professional repairs always involve hard soldering.
How much does it cost to replace a compressor yourself?
The cost consists of the price of a new motor (from 3,000 to 8,000 rubles), the cost of freon, filter-drier and solder. If you do not have a tool (pump, burner), buying or renting it may exceed the cost of calling a technician.
What to do if after replacement the refrigerator does not freeze?
There may be several reasons: freon leak due to poor soldering, clogged capillary tube, insufficient vacuum (wet plug) or incorrect quantity refrigerant charge. Re-diagnosis with a pressure gauge is required.