Replacement compressor - this is one of the most difficult procedures in repairing household appliances, requiring not only mechanical skill, but also an understanding of the principles of operation of the refrigeration circuit. If you are faced with the need to completely dismantle the motor, then most likely we are talking about a serious breakdown that cannot be eliminated by simply replacing the start relay or thermostat. In most cases, the engine is replaced when the windings are shorted between turns, the piston group is jammed, or there are critical refrigerant leaks through the housing.
Before starting work, it is important to realize that the process dismantling is associated with a violation of the tightness of the system, which automatically requires subsequent vacuumization and refilling freon. Carrying out this operation on your own without special equipment (vacuum pump, pressure gauge station) often results in the new motor burning out in the first hours of operation or the system simply stops cooling. However, if your goal is to prepare the unit for professional refueling or you have the necessary tools, then strictly following the algorithm of actions will minimize the risks of damage to other components.
In this article we will analyze in detail the technical nuances of disconnecting lines, features of removing fasteners and safety measures that must be observed when working with electrical devices and potentially dangerous ones substances. When dismantling a compressor, there is always a risk of rupture of pipes and a sudden release of residual oil or gas, so work should be carried out in a ventilated area. Proper preparation of the workplace and the availability of suitable tools is 80% of the success of the entire operation.
Diagnostics and preparation of the worker places
Before taking up the tools, you need to finally make sure that the problem lies in the compressor, and not in the accompanying elements. Often, symptoms pointing to motor malfunctionsuch as lack of cold or a humming noise can be caused by a clogged capillary tube or a failed thermostat. Check the resistance of the windings with a multimeter: if the device shows an open or short circuit, then replacing the motor is inevitable. It is also worth making sure that the start relay is not stuck, as this is the most common cause of false diagnosis.
Preparation of the work area plays a critical role in the safety and speed of work. You will need enough free space to lay the refrigerator on its side or tip it over without damaging the back wall or floor. Be sure to disconnect the appliance from the electrical outlet by removing the plug from the socket and ensure that the work area is well lit. This step should not be ignored, as poor visibility can lead to injury or damage to copper pipes.
⚠️ Attention: Before starting any work, make sure that there are no open flames or sparking devices in the room. Although modern refrigerants (R600a) are used in small quantities, they are flammable gases, and their concentration in a confined space can create an explosive mixture if leaked.
To successfully complete the task, you will need a specific set of tools that are rarely found in a standard home workshop. The main tool will be a pipe cutter, which allows you to make an even cut of copper lines without the formation of chips that could clog the system. You also need wrenches for removing fasteners, pliers, screwdrivers and, preferably, a vice or clamp to secure the housing when cutting tubes.
Necessary tools and safety measures
The quality of the work directly depends on the equipment used. For dismantling refrigeration unit ordinary hacksaws are not suitable for metal, as they leave a lot of metal shavings that can damage a new compressor or clog a capillary. The ideal solution is a professional pipe cutter with minimal clearance between the rollers. If such a tool is not available, you can use a hacksaw with a very fine tooth, but after each cut, careful blowing and cleaning of the cutting area is required.
Protection of hands and eyes is a must. When cutting pipes under pressure (if the gas has not been released in advance) or when working with old oil, splashes are possible that can get on the skin or mucous membranes. Wear safety glasses and thick gloves that are resistant to oils and chemicals. In addition, older refrigerators may contain signs of corrosion and sharp metal edges that can easily injure you.
Particular attention should be paid to electrical insulation. Although the compressor is disconnected from the mains, a residual charge may remain in the capacitors. Before touching the electrical contacts of the start relay, it is recommended to close them with a dielectric screwdriver or simply wait a few minutes. Also check the integrity of the ground wire, if the design of your refrigerator provides for its presence, in order to avoid electric shock during subsequent tests.
List of necessary equipment for safe dismantling:
- 🛠️ Pipe cutter for copper pipes with a diameter of up to 10 mm
- 🔧 Set open-end and spanner wrenches (8-14 mm)
- 🔋 Multimeter for checking electrical circuits
- 🧤 Safety glasses and oil-resistant gloves
- 🪛 Pliers and side cutters for working with clamps
Procedure for accessing the compressor compartment
Access to the motor in most modern refrigerator models, such as Indesit, Ariston or Stinol, is through the back panel. However, in some built-in models or older refrigerators, access may be provided from the bottom or side, which requires partial disassembly of the case. First of all, you need to move the refrigerator away from the wall, ensuring free access from all sides, and remove the protective cover, which is usually fastened with 4-6 screws.
After removing the cover, you will have a view of the compressor, condenser grille and tube system. At this stage, it is important not to jerk the wires and hoses sharply, as the plastic becomes brittle over time. Visually inspect the condition vibration supports and fastenings: often rubber gaskets dry out and crumble, which can cause additional noise during further operation. If you are planning to install a new motor, it is better to replace the old supports immediately.
If access is hindered by a condenser grille (radiator), it is usually not removed completely, but carefully bent or lifted, having first unscrewed the mounting bolts. Be careful with aluminum condenser tubes - they are very soft and easily deformed. Any dent on the radiator impairs heat transfer, which reduces the efficiency of the entire refrigerator. In some models, the radiator is glued to the back wall, and its removal requires heating with a hairdryer, but this is rarely required to replace the compressor.
Access nuances in two-compressor models
In refrigerators with a No Frost system and two motors, they can be located in different niches or in one common one, but separated by a partition. It is important not to confuse the tubes going to different circuits (freezer and refrigerator compartments), since they may have different diameters and pressures.
Before you begin to physically disconnect parts, it is recommended to photograph the location of all tubes and wires. This will help avoid errors during assembly, especially if this is your first time. The color marking of the wires and the diameter of the tubes are key guidelines that will help you correctly connect the new unit.
Disconnecting electrical circuits and tubes
The disconnection process begins with the electrical part. On the compressor housing there is a terminal box covered with a plastic casing. Carefully remove the cover to gain access to the start relay and thermal protection contacts. Before disconnecting the wires, make sure you remember or sketch the connection diagram. Typically, three wires are used: phase, neutral and ground, but the color scheme may differ from one manufacturer to another.
Remove the start relay and capacitor (if it is placed separately) from the compressor pins. They are held in place by a tight fit and are sometimes secured with a metal clip. Do not use excessive force to avoid breaking the plastic ears of the relay. After removing the electrics, you can proceed to the most important stage - cutting the copper lines. Copper tubes approach the compressor at three points: suction (thick), discharge (thin) and sometimes process (soldered).
To disconnect the tubes, use a pipe cutter. Clamp the tube into the tool and rotate it around its axis, gradually tightening the feed screw. Do not squeeze the tube too hard so as not to compress its lumen completely until the cut is made. If you don’t have a pipe cutter and you use a hacksaw, make the cut carefully, trying not to damage adjacent elements. After sawing the tube, immediately clamp the hole with your finger or a plug to prevent moisture and dust from entering the system.
| Tube type | Diameter (approximate) | Location | Function |
|---|---|---|---|
| Suction | 6-8 mm | Back or side, thick | Freon gas intake |
| Discharge | 5-6 mm | Rear, thin | Ejection of compressed gas into the condenser |
| Technological | 6 mm | Bottom or side, sealed | For filling and vacuuming |
⚠️ Attention: Never cut through copper tubes with side cutters or pliers! This action flattens the end of the tube and creates internal chips that are guaranteed to destroy the new compressor or clog the filter drier. Only an even cut or cut.
Removing the compressor from the frame
After all communications are disconnected, it is time to physically remove the engine. The compressor is secured to the refrigerator frame with four bolts or nuts that pass through rubber vibration mounts. These supports are necessary to dampen vibration, so they have a complex shape and require careful handling. When unscrewing the fasteners, hold the motor housing with your other hand so that it does not fall and damage the sealed tubes.
Often the mounting bolts sour or rust, especially if the refrigerator was operated in conditions of high humidity. In such cases, it may be necessary to apply a penetrating lubricant (such as WD-40) and wait for 10-15 minutes. Use a long-handled wrench for better leverage, but avoid sudden jerks that could break the mounting lugs on the compressor itself. If the nut does not give in, it is better to process it again than to tear off the thread.
☑️ Algorithm for removing the compressor
In some models, for example, in old ones ZIL or Minsk, the compressor can be mounted on a skid or have additional brackets. In this case, it may be necessary to remove the entire assembly along with part of the frame. Remove the motor smoothly, making sure that the remaining ends of the tubes on the refrigerator body are not bent or deformed. Remember that the new compressor will be installed in the same holes, so the geometry of the seat should remain unchanged.
After removing the old motor, inspect the rubber bushings. If they have lost elasticity, become cracked or flattened, they must be replaced. Installing a new compressor on old, “oak” supports will result in the refrigerator operating with strong noise and vibration transmitted to the entire body and floor. The cost of a set of supports is low, and the effect of replacing them is very noticeable.
Features of working with different types of refrigerants
When removing the engine, it is important to take into account the type of refrigerant on which the system worked. Modern refrigerators are most often filled with isobutane (R600a), which is a light and flammable gas. Unlike freon R134a or R12, which are heavier than air and do not burn, R600a requires special care when handling any pipes. Although when dismantling the old compressor, the bulk of the gas may have already evaporated, the residues in the oil and pipes can pose a danger.
If you are replacing the compressor with a similar one, the type of refrigerant is usually the same, but always check the nameplate on the new motor. Using a compressor designed for one type of freon with another type of oil or refrigerant is unacceptable. Oils for different freons have different chemical bases (mineral, semi-synthetic, synthetic POE), and mixing or replacing them can lead to the formation of acids that destroy the insulation of the engine windings from the inside.
When working with R600a systems, it is strictly forbidden to use an open flame to solder tubes in the immediate vicinity of the work site until the system has been completely purged. Even a spark from a power tool could theoretically ignite the accumulated gas. Ventilating the room is not just a recommendation, but a necessary condition for safety.
Preparation for installing a new unit
After successfully dismantling the old engine and before installing a new one, it is necessary to inspect the vacated niche. Remove accumulated dust, dirt and old oil that may have leaked when the pipes were disconnected. Cleanliness in the compressor area is important for efficient heat transfer, as many motors are cooled by natural convection of air passing through the rear wall.
The new compressor comes with plugs on the pipes. They should only be removed at the very last moment, just before soldering or connecting. The open pipes of the new motor instantly begin to absorb moisture from the air, which is unacceptable. Moisture in the system turns into ice plugs in the capillary and causes corrosion of internal parts. If you plan to solder the tubes later, keep the plugs closed until the last minute.
Install the new compressor into the seat, carefully guiding the bushings onto the bolts. Do not immediately tighten the fasteners all the way. First, tighten all four nuts, make sure that the motor is level, without distortion, and only then tighten the fasteners evenly. Excessive tightening force may crush the rubber mounts or deform the compressor housing, resulting in vibration and noise.
⚠️ Attention: Compressor specifications may vary, even within the same refrigerator model. Before purchasing and installing, be sure to check the power, type of refrigerant, volume of refrigerant and type of oil with the data on the nameplate of the old motor or in the manufacturer’s technical documentation.
After the mechanical installation, the stage of connecting the electrics and soldering the pipes begins, which requires completely different skills and tools. However, the correct dismantling preparation described above is the foundation for the successful completion of the repair. If you are not confident in your abilities at the soldering or vacuum stage, it is better to stop at the removal stage and invite a specialist for final assembly and refueling.
Is it possible to remove the compressor without releasing the freon?
Technically, you can unscrew the bolts, but it is impossible to cut the tubes without releasing the gas. Freon is in the system under pressure. If you try to saw off the tube, the gas will come out with a characteristic whistle. It is not recommended to specifically vent it indoors, especially if it is R600a. Professionals use a puncture of a tube connecting a tap to collect gas, but at home the gas is simply released into the atmosphere, which is environmentally unsafe.
Is it necessary to flush the system when replacing a compressor?
Yes, flushing with nitrogen is required if the old compressor has burned out. When the windings burn, acid and combustion products enter the system, which will quickly kill the new motor. If the compressor simply stops pumping without a short circuit, it is enough to replace the filter drier and bleed the system. Ignoring flushing after combustion is the main cause of repeated breakdowns.
Why does the new compressor get hotter than the old one?
This is normal for the first hours of operation. New motors often have different efficiency and housing temperatures. However, if the compressor becomes too hot to touch and the refrigerator does not cool, there may be air in the system, the refrigerant is incorrectly selected, or the capillary is clogged. Also, the reason may be the lack of clearance between the motor and the wall for ventilation.
Which tool is best for unscrewing the compressor nuts?
It is best to use socket heads with a wrench or ring wrenches. Open-end wrenches often come off the edges of the nuts, especially if they are stuck. The head provides better coverage and distribution of force, which reduces the risk of damage to fasteners and hand injuries.