Failure of the main unit of the cooling system is always stressful for the owner of household appliances, because the safety of food and comfort in the home are at stake. However, there is no need to panic, since in most cases a faulty one can be replaced yourself if you have minimal skills in working with tools and electrical equipment. This procedure requires care and compliance with safety precautions, but it allows you to save a significant amount on calling a technician. unit You can replace it yourself if you have minimal skills in working with tools and electrical equipment. This procedure requires care and compliance with safety precautions, but it allows you to save a significant amount on calling a specialist.
Before starting disassembly, you need to make sure the diagnosis is accurate, since symptoms of a non-working motor may indicate problems with the starting relay or thermostat. If diagnostics confirm that compressor it is burnt out or jammed, replacing it becomes the only correct solution to restore the functionality of the device. It is important to understand that the process involves working with refrigerant and high temperatures during soldering, so precautions cannot be ignored.
The success of the operation directly depends on the quality of workplace preparation and the availability of specialized equipment, such as a torch and vacuum pump. In this article we will analyze in detail each stage of dismantling the old unit and installing a new one, paying special attention to the nuances of soldering copper tubes and filling the system freon. Even if you do not plan to do the work personally, this knowledge will help control the quality of the service center's services.
Diagnostics and selection of a new unit
The first step is to accurately identify the problem: if the motor hums but does not start, or it is completely silent when plugged in, it is likely to fail. To replace, it is necessary to select a model that fully matches the characteristics of the original, otherwise the cooling system will not work correctly or will fail again in the shortest possible time. It is critically important to consider the power, type of refrigerant and overall dimensions of the seat.
When choosing a new part, pay attention to the markings on the nameplate of the old device, as well as the type of oil and freon used. Modern inverter models require special care during installation, as they are sensitive to the cleanliness of the system and the presence of moisture. For old Soviet refrigerators and modern models from Indesit or Atlant units are often used that are similar in design, but different in parameters.
⚠️ Attention: Using a compressor designed for a different type of refrigerant (for example, R600a instead of R134a), is strictly prohibited and can lead to an explosion or fire due to differences in operating pressures and properties of oils.
To avoid making a mistake with the choice, compare the following parameters on the body of the old and new part:
- 🔌 Power engine (usually indicated in fractions of horsepower, for example, 1/4 or 1/5 hp).
- ❄️ Refrigerant typethat the compressor is designed to work with (R134a, R600a, R12).
- 📏 Dimensions and the location of the mounting holes so that the device fits into the standard place.
- 💨 Performance (cm³/h), which should be equal to or slightly exceed those of the original.
Is it possible to install a more powerful compressor?
Theoretically, it is possible to install a larger unit power, but this will lead to a violation of the thermal balance. The evaporator will not have time to give off cold, and the condenser will not have time to dissipate heat, which will cause constant operation of the motor at the limit of its capabilities and rapid wear.
Necessary tools and materials
A high-quality replacement is impossible without the proper tools that will ensure the tightness of the connections and the safety of the process. The main list includes tools for working with copper, electrical and vacuum systems. The absence of at least one key element may result in the refrigerator not working or operating with low efficiency.
To work, you will need specific tools that are not always available at home, so they often have to be purchased separately or rented. Pay special attention to the quality of soldering equipment, since copper tubes require quick and accurate heating without burning out the walls.
Assemble the following set before starting work:
- 🔥 Gas torch with a set of solder (silver or copper-phosphorus) and flux for soldering.
- 🔧 Pipe cutter for clean cutting of copper tubes without the formation of chips inside.
- 🌬️ Vacuum pump and manometric station for removing air and moisture from the circuit.
- ⚖️ Electronic scales for precise dosage of refrigerant charged.
Preparation of the refrigerator and dismantling the old compressor
Before starting any manipulations, the device must be completely de-energized by unplugging the plug from the socket and moved away from the wall to ensure access from all sides. It is advisable to unload all the products and defrost the chamber so that the water does not interfere with work and does not damage the internal elements when the unit is tilted. You should work in a well-ventilated area, since the combustion of oil and freon can release harmful substances.
The dismantling process begins with removing the protective panel on the back of the refrigerator, under which the motor-compressor and condenser grille are hidden. Carefully disconnect the wires from the start relay and motor terminals, having previously photographed the connection diagram so as not to mix up the contacts during assembly. Then it is necessary to bleed off the remaining refrigerant if it is still in the system, although it may no longer be in the faulty unit.
Next comes the most critical stage - unsoldering the copper tubes from the compressor fittings. Heat the joint evenly with a torch until the solder becomes liquid, then carefully remove the tube. Do not allow moisture to get on the heated metal to avoid cracks.
☑️ Dismantling checklist
Installing and soldering the new one compressor
Installation of a new unit is carried out in the reverse order of dismantling, but in compliance with strict soldering and tightness rules. Before installation, make sure that the transport plugs on the pipes of the new compressor are removed only at the time of connection, so that dust and moisture do not get inside. Attach the motor to the refrigerator frame using original shock absorbers or new damper bushings to reduce vibration and noise during operation.
Soldering copper joints requires skill: the torch flame is directed at the junction of the tube and fitting, and not at the solder itself. When the metal heats up to the desired temperature, the solder itself will flow into the gap under the influence of capillary effect. It is important to heat the connection strongly enough, but not to burn the copper, as this will lead to the formation of oxides inside the tube, which can subsequently clog the capillary system.
During the soldering process, use nitrogen purge or at least minimize the heating time to prevent the formation of an oxide film inside the circuit. Copper oxides, entering a thin capillary, can completely block the circulation of the refrigerant, which will negate all repair efforts.
| Connection type | Soldering temperature | Solder type | Features |
|---|---|---|---|
| Copper-Copper | 600-700°C | Copper-phosphorus | Does not require flux, self-fluxing |
| Copper-Steel | 700-800°C | Silver with flux | Requires mandatory use of flux |
| Aluminium | Special. solders | Zinc-tin | Complicated soldering, requires stripping |
Evacuation and charging with refrigerant
After installation and checking the tightness of the connections (usually with a soap solution or under nitrogen pressure), the evacuation stage begins. This is a critical procedure to remove air and, more importantly, water vapor from the system. Moisture in the system freezes in the capillary, forming an ice plug that blocks the circulation of freon, or reacts with the oil, forming acid that corrodes the windings.
Connect the pressure gauge station and vacuum pump to the service connection. Turn on the pump and watch the vacuum gauge needle: it should show a deep vacuum (usually below -1 bar or 200-300 microns). The process should last at least 15-20 minutes, after which the valve is closed and the system is left under vacuum for some more time to control the tightness.
⚠️ Attention: Never start the compressor if there is air or moisture left in the system. This is guaranteed to lead to water hammer, destruction of valves and repeated failure of expensive equipment.
Filling with refrigerant is carried out strictly according to the weight indicated on the factory sticker of the refrigerator (usually inside the chamber or on the back wall). The freon cylinder is weighed, and exactly as many grams as required are released into the system. Different types of freons (R134a, R600a) may require different hoses and oils, since they are not always compatible.
Starting and checking operation
After refueling, you need to start the refrigerator and check its operation for the first hour. Normally, the compressor should operate cyclically: turn on, cool the chamber to a set temperature and turn off according to a signal from the thermostat. Touch the condenser grille from behind: it should warm up evenly, and cold should appear in the freezer compartment.
Pay attention to the noise level: a new, working unit operates smoothly, without clanging, knocking or excessive vibration. If a metallic knock is heard or the hum changes suddenly, moisture may have entered the system or an air lock has formed, which requires repeated evacuation and refilling.
Check the tightness of all soldered seams again using soap foam or a special leak detector, especially after the system has been operating and warmed up. The absence of bubbles indicates high-quality soldering. If all parameters are normal, you can install the protective back cover and return the refrigerator to operation.
Questions and answers (FAQ)
Is it possible to replace the compressor without a vacuum pump?
It is strictly not recommended. Purging with freon (the “displacement method”) does not completely remove moisture, which will lead to acid formation and capillary blockage after a short time. Evacuation is a mandatory step for the longevity of the repair.
Why does a new compressor get very hot?
Strong heating can be caused by excessive freon charging, the presence of air in the system, a malfunction of the condenser, or improper operation of the thermostat. It is also possible that the power of the installed unit does not correspond to the volume of the chamber.
How long does it take to replace a compressor?
For an experienced technician with all the tools, the process takes from 1.5 to 3 hours, including time for soldering, vacuuming (20-30 minutes) and initial start-up. Replacing it yourself without experience can take much longer.
Do you need to change the filter drier when replacing the compressor?
Yes, the filter drier is a disposable element. Every time the circuit is opened and air enters, it must be replaced with a new one, since the old one is already saturated with moisture and will not be able to effectively protect the system.