The situation when LG refrigerator stops freezing, and there is silence inside or, conversely, a loud knock is heard, often indicates a failure of the main unit - the compressor. This is the heart of the cooling system, and its failure requires immediate attention. Replacing this unit yourself is possible, but requires specialized tools, knowledge of the basics of electrical engineering and strict adherence to safety regulations.
Before proceeding with dismantling, you need to make sure that the problem lies in the motor, and not in the start relay or thermostat. Often users confuse these faults, buying an expensive part without a real need. If you are confident in the diagnosis, then preparing for the repair will take a significant part of the time, since it will require not only mechanical replacement, but also work with the refrigerant.
In this guide, we will analyze the replacement process in detail, paying special attention to the nuances of working with linear inverter compressors, which are equipped with many modern LG models. Remember that a leak in the circuit or improper soldering can lead to complete failure of the equipment. Be attentive to details and do not skip preparation steps.
Fault diagnosis and spare part selection
The first step is to accurately identify the problem. If compressor it hums but does not start, or turns on for a couple of seconds and clicks, this may indicate a jammed piston group or a winding break. In the case of LG inverter models, such as series marked Linear Inverter, diagnostics are more complicated and often require connecting a diagnostic adapter.
When choosing a new spare part, it is critical to focus not only on the power, but also on the type of refrigerant. Modern LG refrigerators run on R600a (isobutane) or R134a. Using a compressor designed for a different type of freon will lead to incorrect operation of the lubrication system and rapid wear.
It is also necessary to take into account the overall dimensions of the seat. Despite standardization, the distances between the mounting legs may differ by several millimeters, which will require drilling new holes or using adapter plates. Always check the model of the old unit with the catalog number of the new one.
⚠️ Attention: When purchasing a compressor, pay attention to the diameter of the fittings (outlet tubes). If they differ from the standard ones, you will need to additionally purchase copper adapters, which increases the number of solder connections and the risk of leakage.
Do not ignore the state of the starting relay. Even if you change the motor, the old relay may not match the electrical characteristics of the new unit. Ideally, replacement starting relay and protective thermal relay need complete with the compressor.
Required tools and materials
For One set of wrenches will not be enough to get the job done efficiently. You will need specialized equipment to work with refrigeration circuits. Without it, it is impossible to ensure tightness and proper filling of the system.
- 🔧 Set of pipe cutters and a rolling machine - necessary for carefully cutting copper tubes and creating tight connections without using soldering in hard-to-reach places.
- 🔥 Gas burner (propane-oxygen or supercharged propane-butane) - for soldering copper tubes with hard solder.
- 💨 Vacuum pump and pressure gauge station - are required to remove moisture and air from the circuit before charging with freon.
- ⚖️ Electronic scales —for precise dosage of refrigerant, since filling “by eye” is unacceptable.
- 🧪 Nitrogen —for purging the system and checking for leaks under pressure.
In addition, you will need consumables: copper solder containing silver (phosphorus-copper), flux, industrial alcohol for degreasing and, of course, itself refrigerant in a cylinder. Do not forget to prepare a container to collect old oil that may leak during dismantling.
☑️ Preparation for repair
Removing the old compressor
The removal process begins with providing access to the unit. Turn the refrigerator over or remove the back panel at the bottom of the cabinet. Before starting work, be sure to disconnect the device from the power supply. Allow the compressor to cool down if it has been running recently.
The first step is to bleed off any remaining refrigerant. To do this, a neat cut is made on the filling tube or the Schrader valve is pierced. This should be done in a well-ventilated area, as the gas may be toxic or flammable (especially R600a).
Then you should unsolder the suction and discharge tubes. Heat the soldering area with a torch evenly until the solder becomes liquid. After this, the tubes are separated. Be careful: there may be oil under pressure inside the tubes.
Disconnection procedure:1. Bite off the filling tube.
2. Unsolder the discharge pipe (outlet).
3. Unsolder the suction pipe (input). data-i="106">Unscrew the mounting bolts holding the compressor to the frame. Some LG models use rubber anti-vibration bushings that need to be carefully removed. If the compressor is linear, it can be mounted on special skids that also require dismantling.
Remove the mounting bolts holding the compressor to the frame. Some LG models use rubber anti-vibration bushings that need to be carefully removed. If the compressor is linear, it can be mounted on special skids, which also require dismantling.
What to do with the oil?
Old oil from the compressor contains acidic impurities and decomposition products. Do not pour it into the sewer or onto the ground. Collect the liquid in a sealed container and take it to a waste disposal point.
Preparation and installation of a new unit
The new compressor is supplied filled with nitrogen under pressure. This is done to prevent moisture from entering and oxidizing the internal surfaces. at the very last moment, just before soldering.
If the geometric dimensions of the new motor are different, the frame may need to be modified. However, most often the problem is solved by selecting the correct adapters for the tubes. The length of the copper tubes should be sufficient for convenient rolling or soldering.
When installing, pay attention to the angle of inclination. specified in the documentation. A tilt of more than 40 degrees can lead to oil leaking from the engine compartment into the circulation circuit, which will cause hydraulic shock at startup.
| Parameter | Standard value | Critical value | Consequences of violation |
|---|---|---|---|
| Inclination angle | 0-10 degrees | > 40 degrees | Oil getting into the circuit, breakdown valves |
| Nitrogen pressure | 15-20 bar (check) | < 0 bar (vacuum) | Case destruction, air ingress |
| Temperature soldering | 600-700 °C | > 800 °C | Copper burn, leakage |
| Evacuation time | 30-60 minutes | < 15 minutes | Residual moisture, ice plug |
Attach the new compressor to the frame using new vibration bushings. Old rubber bands often become tanned and lose elasticity, which will lead to increased noise when the new motor operates.
Soldering tubes and assembling the circuit
The most important stage is connecting the copper tubes. If you use the rolling method, make sure that the cut surface is perfectly smooth and clean. When soldering, it is necessary to use flux, but its quantity should be minimal so that excess does not flow into the system.
When working with isobutane (R600a) special care should be taken. This gas is explosive. Before soldering, make sure that there are no refrigerant vapors in the work area. Purge the tubes with nitrogen before final sealing to displace any remaining gas.
The soldering process is as follows: heat the joint evenly, touch the solder (not the torch flame). The solder should melt and be drawn into the gap by capillary action. Do not overheat the copper; it should not turn dark cherry.
⚠️ Attention: Never leave compressor or condenser tubes open for more than 5-10 minutes. Copper actively absorbs moisture from the air, which will subsequently turn into ice and clog the capillary tube.
After soldering all connections, it is necessary to allow the metal to cool naturally. Do not use water or compressed air to speed up the process, as sudden temperature changes can cause microcracks in the seams.
Evacuation and filling refrigerant
Simply replacing the compressor is not enough - you need to create conditions for the refrigerant to work. The system must be completely dry. To do this, connect vacuum pump to the service pipe through a pressure gauge station.
Turn on the pump and monitor the readings of the vacuum gauge. The process should last at least 30-40 minutes. If, after turning off the pump, the pressure gauge needle begins to creep up, it means that there is a leak in the system or moisture is evaporating.
Refilling with freon is carried out strictly by weight. On the back wall of the refrigerator (on the nameplate) the exact mass of the refrigerant in grams is indicated. For LG models this is usually from 50 to 140 grams depending on the volume of the cameras. Overfilling is just as dangerous as underfilling.
Refilling algorithm:1. Create a vacuum (up to -1 bar).
2. Close the pump valve.
3. Open the valve of the freon cylinder.
4. Start the scales and release gas to the desired mass.
5. Start the compressor and monitor the currents.
After refueling, start the refrigerator and check the current consumption. They must match the rating shown on the compressor label. If the current is higher, there may be an overload or excess freon. If it is lower, there is a leak or underfilling.
Typical errors and safety measures
One of the most common mistakes is neglecting nitrogen purging. If you skip this step, the oxide film inside the tubes may clog the filter drier. Also, craftsmen often forget to replace the filter drier, which is strictly prohibited.
When working with electricity, remember that LG inverter compressors are controlled by complex electronics. A direct connection to a 220V network without a starting module (for inverters) will damage the motor instantly. Check the type of motor before connecting.
- 🚫 Error: Use regular POS-60 solder instead of solid copper-phosphorus solder. Soft solder does not withstand vibrations and temperature expansion.
- 🚫 Error: Filling “by eye” using pressure. The pressure in the system depends on the ambient temperature and load; you only need to focus on the weight.
- 🚫 Error: Ignoring the replacement of the filter drier. The old filter is already saturated with moisture and will not work effectively.
Always use personal protective equipment. If freon comes into contact with the skin, it causes frostbite, and when heated with an open flame, it decomposes to form phosgene, a poisonous gas.
⚠️ Attention: Technical characteristics of refrigerators and requirements for refrigerants may be changed by manufacturers. Always check the technical documentation (service manual) for your specific LG model before starting work.
FAQ: Frequently Asked Questions
Is it possible to replace an LG compressor with an analogue from another brand?
Yes, This is possible if the installation dimensions, power, type of refrigerant and application (LBP or HBP) are the same. However, for LG inverter models, it is better to use original spare parts or certified analogues, since the operating algorithms of the electronics may differ.
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. Most of the time is spent on evacuating the system and waiting for the solder joints to cool. Self-repair without experience can take the whole day.
Why does the new compressor get hotter than the old one?
This is normal for modern energy-efficient models. They operate at higher condensation temperatures. The main thing is that the thermal protection relay is activated and the housing does not overheat to temperatures dangerous for plastic.
Is it necessary to flush the system when replacing a compressor?
If the old compressor burns out and releases oil into the system, flushing with nitrogen is mandatory. If it simply stops pumping due to mechanical wear without burning, it is enough to replace the filter-drier and blow out the circuit.