The situation when the refrigerator stops cooling and the motor hums, but does not start or turns off immediately, often indicates a serious problem within the system. In most cases, the culprit is a clogged capillary tube or the presence of moisture in the freon circuit, which requires complex intervention. Flushing a refrigerator compressor is not just an oil change, but a complex technical procedure that requires an understanding of the principles of operation refrigeration circuit and the presence of specialized equipment.
Many owners of household appliances mistakenly believe that it is enough to simply pour new liquid inside the unit to make it work again. However, the system is sealed, and the ingress of engine combustion products or copper oxides can completely block the circulation of the refrigerant. If you encounter such a malfunction, it is important to act consistently, observing safety precautions and the technological process.
In this article we will look in detail at how to flush a refrigerator compressor, what tools you will need for this, and why standard solvents like acetone can be dangerous for some components. We will consider the stages of dismantling, choosing a suitable flushing liquid and the nuances of evacuation of the system before refueling.
Diagnostics and signs of the need for flushing
Before you begin disassembling the unit, you need to make sure that the problem lies precisely in contamination of the system. The main sign of the need for flushing is clogged capillary tube, which is often accompanied by overheating of the compressor and lack of cold in the chambers. In this case, the motor can work continuously, trying to gain temperature, or start for just a few seconds.
Another alarming signal is a change in the color of the oil when it is drained. If the liquid has a dark, almost black tint and contains mechanical impurities or an acidic odor, this indicates combustion of the windings or decomposition of the oil. In such a situation, simply replacing the filter-drier will not help; you will need a complete flushing the circuit refrigerator.
It is also worth paying attention to the presence of moisture in the system. If, when opening the pipeline, you hear hissing or notice drops of water, this means that depressurization has occurred and atmospheric air has entered the system. Moisture combines with oil and refrigerant to form a corrosive acid that destroys insulation and metal parts.
⚠️ Attention: If the compressor makes a knocking or clanging noise when trying to start, flushing will not help. This is a sign of mechanical destruction of the valve group or jamming of the pistons, which requires replacement of the unit.
Accurate diagnosis often requires opening the system and visual inspection of the internal surfaces of the pipes. The presence of black deposits on the walls of copper tubes confirms the need for complete cleaning of all elements of the refrigeration cycle.
Necessary tools and materials
High-quality washing is impossible without the right tools. You will need not only a set of wrenches, but also specific equipment for working with refrigeration systems. The main tool will be vacuum pumpwhich is necessary to remove moisture and air from the circuit after flushing.
It is also necessary to have a pressure gauge station to control the pressure during purging and filling. Without this device, it is impossible to accurately determine whether the blockage has been removed and whether the system is sealed. For the cleaning procedure itself, you will need a large-volume syringe or a special bulb for pumping liquid.
- 🛠️ Set of pipe cutters and rollers - for careful dismantling and subsequent restoration of copper pipelines without soldering unnecessary connections.
- 🧪 Washing liquid - a specialized solvent (for example, R141b) or purified gasoline "Galosh" that does not leave an oily residue.
- 🔥 Burner and solder —for sealing the system after completing all cleaning procedures and replacing the filter.
Special attention should be paid to the choice of flushing liquid. The use acetone or aggressive solvents is strictly prohibited, as they can damage the insulation of the motor windings and rubber seals. It is best to use special compounds intended for refrigeration equipment, or high-octane gasoline.
Do not forget to prepare a container for draining old oil and flushing fluid. It must be clean and dry so that you can visually assess the degree of contamination of the system. You will also need new consumables: a filter drier and refrigerant of the brand indicated on the compressor nameplate.
Preparing the refrigerator for maintenance
The first stage of work is the complete preparation of the unit. The refrigerator must be disconnected from the power supply and defrosted if there is ice left in the chambers. After this, the equipment should be rolled out to a free, well-lit space, providing access from all sides.
Next, the compressor is dismantled. To do this, the copper tubes going to the discharge and suction pipes are cut or soldered off. It is important to carefully cut off the capillary tube so as not to damage its internal diameter, as this can aggravate the blockage problem.
The next step is to drain the old oil. The compressor is turned upside down, and liquid is drained from the lower sealed tube (if there is one) or through the bitten off suction pipe. By its color and smell, you can draw preliminary conclusions about the condition of the internal components.
After draining the oil, you need to remove the starting relay and the protective thermal contact. These elements are not washed, but are tested separately for functionality. If the relay has cracks or a burning smell, it must be replaced with a new one that matches the engine model.
Technology for flushing the compressor and system
The flushing process itself requires care and adherence to the sequence of actions. First you need to determine where exactly the source of pollution is. If the motor burns out, then first of all you need to wash the compressor itself and the condenser. In such cases, the evaporator often remains clean, since the flow of combustion products goes towards the discharge.
Rinsing is carried out using the circulation or soaking method. In the case of a compressor, liquid is poured through the suction pipe, after which the holes are temporarily sealed or tightly plugged. The unit must be shaken periodically so that the solvent dissolves oily deposits and decomposition products.
For more effective cleaning, you can use the pressure blowing method. The flushing liquid is introduced into the system and then blown out with compressed nitrogen or air. This operation is repeated several times until the emerging liquid becomes clear.
- 💧 Soaking - pouring solvent inside the compressor housing for several hours to soften solid deposits.
- 🌬️ Nitrogen purging - using inert gas to displace dirt and residual moisture from hard-to-reach places.
- 🔄 Circulation - driving liquid through the entire system using an external pump (used in difficult cases).
The evaporator is usually washed separately or simply purged if it has not been affected by combustion products.
⚠️ Attention: It is strictly forbidden to leave the flushing liquid inside the system for a long time without movement. Aggressive components can begin to corrode the metal walls of pipes with prolonged contact.
After completion of washing, all elements must be thoroughly dried. Solvent residues are unacceptable, as they will change the properties of the oil and can lead to the formation of an acidic environment during operation of the refrigerator.
Replacing the filter-drier and assembly
One of the critical steps is replacing the filter-drier. This element is disposable and after opening the system or washing it loses its properties. The old filter must be carefully sawed off or bitten off, being careful not to damage the adjacent tubes.
The new filter is installed strictly in accordance with the flow direction indicated by the arrow on the housing. Before soldering, it is recommended to heat it with a torch to remove moisture accumulated from the air, but not to overheat it red-hot, so as not to damage the filler.
☑️ System assembly checklist
The system is assembled in the reverse order. All solder connections must be made with high quality, without kinks or narrowing. You should use only refractory solder and flux that do not cause corrosion of copper.
After soldering all elements, the system is pressurized with nitrogen. This allows you to check the tightness of connections under pressure exceeding operating pressure. If the pressure is maintained for 20-30 minutes, you can proceed to evacuation.
| Work stage | Required equipment | Success criterion |
|---|---|---|
| Rinsing | Solvent, syringe/bulb | Clean liquid output |
| Drying | Compressed air/nitrogen | No solvent vapor |
| Vacuuming | Vacuum pump, pressure gauge | Pressure below -0.98 bar |
| Refilling | Scales, freon cylinder | Refrigerant weight according to standard |
Evacuation is the process of removing air and moisture from the circuit. The pump should run for at least 30-40 minutes. Stopping the evacuation ahead of time will result in moisture remaining in the system, which will freeze in the capillary tube and again cause blockage.
Why can’t you use air for pressure testing?
Using ordinary air to create pressure is dangerous, since it contains moisture. During compression and subsequent cooling, this moisture condenses inside the system, causing corrosion and ice plugs. Use only dry nitrogen.
Refrigerant charging and testing
The final stage is filling the refrigerator with freon. The type of refrigerant and its quantity are indicated on a technical sticker, usually located on the back wall or inside the chamber. Violation of the dosage can lead to both insufficient cooling and compressor failure.
Refilling is best done in the liquid phase through a filter drier or a special valve, monitoring the weight on an electronic scale. After refueling, it is necessary to start the compressor and check the operation of the system.
The check includes assessing the temperature of the condenser (it should warm up evenly) and the evaporator (it should be cooled). The absence of extraneous noise and vibrations is also checked.
- 🌡️ Temperature mode —checking that the temperature in the chambers corresponds to the set values.
- 🔊 Acoustic control —listening to the operation of the motor for knocking or humming.
- 💨 Checking the tightness - applying a soap solution to the soldering areas to detect leaks.
If all parameters are normal, the capillary tube is finally sealed, and the refrigerator is left for long-term operation under supervision. During the first hours of operation, the compressor housing may slightly heat up, which is a normal running-in process.
Common mistakes and precautions
When doing work with their own hands, craftsmen often make mistakes that nullify all efforts. The most common of them is insufficient vacuuming. The remaining moisture leads to the formation of an ice plug in the capillary after just a few hours of operation.
Another mistake is the use of unsuitable oils. Compressors of different types (mineral, synthetic, polyester) must be filled with strictly defined oil. Mixing different types can lead to the formation of sediment and jamming of the mechanism.
⚠️ Attention: Never run the compressor “dry” or with open pipes for testing. This will instantly suck in dust and moisture, and can also cause sparking and ignition of oil vapors.
Overheating of the tubes when soldering should also be avoided. Excessive heating leads to the formation of oxides inside the pipe, which subsequently fall off and cause a new blockage. Use a damp rag to cool adjacent areas when soldering.
Compliance with technology and the use of the right materials is the key to the long service life of a repaired refrigerator. If you are not confident in your abilities, it is better to entrust this work to professionals, since the cost of a mistake can be equal to the cost of a new unit.
Is it possible to flush the compressor without removing it from the refrigerator?
Theoretically, this is possible if you have access to the tubes, but it is extremely ineffective. Without dismantling, it is impossible to properly drain the old oil, shake the solvent inside the housing and ensure full circulation of the liquid. In addition, there is a high risk of damaging other components of the refrigerator with aggressive chemicals.
What is better to wash: gasoline or a special solution?
Special solutions (for example, R141b) are preferable, since they do not leave an oily film, completely evaporate and do not damage the insulation of the wires. Galosh gasoline is an acceptable alternative, but requires more thorough drying. Regular motor gasoline cannot be used due to additives.
Is it necessary to change the oil in the compressor after flushing?
Yes, definitely. Old oil contains decay products and acid. After flushing, fresh oil of the same brand and viscosity as it was originally is poured into the compressor. The amount of oil must also strictly comply with the manufacturer's specifications.
Why does the refrigerator not freeze after washing?
There may be several reasons: there is a blockage in the capillary tube, the vacuum has not been pumped out sufficiently (moisture remains), freon is not charged correctly, or a defective filter-drier is installed. It is also possible that the compressor has a hidden defect in the valves, which appeared after cleaning.
Is it dangerous to open the refrigerator system yourself?
Yes, it is fraught with risks. First, some refrigerants are flammable and explosive when exposed to air. Secondly, working with open flames and gas requires skills. Thirdly, improper soldering can lead to gas leakage and food spoilage. If you have no experience, it is better to contact the service.