The situation when the refrigerator stops freezing and the temperature inside rises often takes you by surprise. The main heart of any refrigeration unit is compressorwhich ensures the circulation of refrigerant throughout the system. It is this unit that most often fails during prolonged use or power surges in the network.
Having decided to replace it yourself, you take responsibility for safety and results. Removing the motor is a technically complex procedure that requires not only physical strength, but also specific tools. It is important to understand that simply unscrewing the parts is not enough: the system is sealed and under pressure.
In this article we will analyze in detail the process of dismantling a faulty unit, paying special attention to the nuances of working with copper tubes and electrical contacts. Proper preparation and adherence to the sequence of actions will help to avoid fatal mistakes that can lead to final equipment failure.
Diagnostics and preparation of the workplace
Before taking active steps, you need to make sure that the problem lies in the compressor. Often, symptoms resembling engine failure can be caused by a freon leak or a malfunctioning thermostat. If you hear a hum, but the cold does not come, or the engine tries to start and immediately clicks, a replacement will most likely be required.
The workplace should be organized taking into account safety requirements. You will need enough space around the refrigerator as the unit will have to be tilted. It is better to cover the floor with thick fabric or cardboard so as not to damage the floor covering and not to lose small parts.
⚠️ Attention: Before starting any work, be sure to disconnect the refrigerator from the power supply. Working with live electrical appliances is strictly prohibited and deadly.
To perform the task efficiently, you will need a set of tools. You should not try to replace the compressor using only pliers and a screwdriver - this will damage the tubes and make it impossible to further seal the system.
Necessary tools and consumables
The configuration of your workplace directly affects the success of the operation. The main tool for working with copper tubes is pipe cutter. Using a hacksaw is not recommended as it leaves chips that can clog the system and damage the new compressor.
You will also need a torch for soldering copper joints. In domestic conditions, propane-oxygen torches are often used, but for high-quality brazing, a higher temperature flame may be required. Don't forget to prepare solder and flux appropriate for the type of metal.
- 🔧 Set of wrenches and screwdrivers (phillips and flat)
- 🔥 Gas torch with cylinder and soldering kit
- ✂️ Pipe cutter and roller (for forming cones)
- 🧤 Protective gloves and safety glasses
Special attention should be paid to the vacuum pump and pressure gauge station. After installing a new motor, the system must be vacuumed to remove moisture and air. Without this step, the refrigerant will not work correctly, and acid will form inside the system, destroying parts.
Access to the compressor compartment
The process begins by gaining access to the bottom of the refrigerator. In most modern models, the compressor is located in a niche in the rear of the housing. You will need to remove the protective panel, which may be secured with latches or screws.
Carefully unscrew the fasteners and remove the cover. Under it you will see itself compressor, a capacitor (black coil on the back) and a start-up relay. Assess the condition of the wires and tubes visually: there should be no obvious traces of oil, indicating a leak, or melted insulation.
For ease of operation, it is better to move the refrigerator to the middle of the kitchen and provide access from all sides. If the model is built-in, it will have to be completely removed from the niche. This is a labor-intensive process that requires the help of a second person due to the weight and dimensions of the equipment.
☑️ Preparation for dismantling
Inspect the mounting of the motor to the frame. It is usually mounted on four shock-absorbing studs with rubber bushings. These elements dampen vibration. When dismantling, it is important not to damage them, although in case of severe corrosion, the rubber gaskets often have to be changed.
Disconnecting the electrical contacts
The next stage is working with the electrics. On the compressor housing there is a start-up relay and a thermal relay. They are put directly on the terminals of the motor windings. You need to remove them carefully, having previously photographed the connection diagram.
Disconnect the wires going to the relay. In some models they can be twisted into a bundle and secured with plastic clamps. Cut the clamps and free the wires so that they do not interfere with further access to the tubes.
⚠️ Attention: Contacts may be oxidized. Do not use excessive force when removing the relay, so as not to break off the copper leads of the compressor, which are very fragile.
After removing the relay, check the condition of the contacts. If they show carbon deposits or traces of melting, this confirms an electrical fault. However, even if the relay is working properly, if the motor is jammed, it will burn out constantly, so they usually change the pair: motor and relay.
Marking of terminals
On most compressors, the terminals are marked as C (Common), S (Start) and R (Run). Mixing up the contacts when connecting a new motor can lead to instantaneous burnout of the winding.
Removing the copper tubes and removing the motor
The most crucial moment is disconnecting the copper tubes. There are two of them on the compressor: one suction (thicker) and one discharge (thinner). Never bite them off with side cutters or saw them off without preparation.
Use a pipe cutter to make an even cut at a distance of 10-15 cm from the compressor housing. After cutting the tubes, residual gas will escape from the system. Be prepared for a hissing sound. Do not inhale refrigerant vapors - they displace oxygen and can be toxic.
The compressor is now held in place only by mounting bolts or studs. Unscrew them with the key. The motor is heavy, so hold it with your hand so that it does not fall to the floor and damage the floor or its own parts.
| Connection type | Tube diameter | Tool | Feature |
|---|---|---|---|
| Suction | 6-8 mm | Pipe cutter | Comes from the evaporator |
| Discharge | 4-6 mm | Pipe cutter | Goes to the condenser |
| Filling station | 3-4 mm | Pliers | Soldered, cut |
| Fasteners | - | Key 10-12 | Rubber bushings |
When removing the old motor, used compressor oil may leak out of it. It is black and has a specific smell. Immediately dispose of it in a closed container, without pouring it onto the floor or down the drain.
Installation of a new compressor and soldering
Installation of a new unit is carried out in the reverse order of dismantling. First of all, secure the motor to the frame by putting on new rubber shock absorbers. Then proceed to soldering the tubes.
Clean the ends of the copper tubes from oxides and burrs. Place the tubes onto the fittings of the new compressor. The gap should be minimal, but the tube should fit freely. When soldering, use solder containing silver for greater joint strength.
Heat the connection with a torch evenly, without holding the flame at one point for too long, so as not to burn through the thin wall of the tube. When the copper heats up, touch the joint with solder - it should melt and flow into the gap under the action of capillary effect.
After soldering, allow the joints to cool naturally. Do not cool them with water or compressed air, as a sharp temperature change can cause microcracks in the metal.
Evacuating and charging with refrigerant
Simply replacing the motor and soldering the tubes is not enough. There is air and moisture left in the system, which are strictly unacceptable. To remove them, connect the pressure gauge station and vacuum pump to the service connection.
The vacuum process takes from 30 minutes to an hour, depending on the power of the pump and the length of the circuit. The pressure should drop to a deep vacuum. This allows the moisture remaining in the system to boil away at low pressure.
After evacuation, close the valve and turn off the pump. If the pressure gauge needle remains in place, then the system is sealed. Now you can refill refrigerant (freon) in accordance with the markings on the refrigerator label.
⚠️ Attention: The type of refrigerant (R134a, R600a, R12) must strictly correspond to the one for which the refrigerator is designed. Using the wrong gas can lead to an explosion (in the case of R600a) or ineffective operation.
Refueling is carried out with the compressor turned on, monitoring the pressure using a pressure gauge and the current consumption of the motor using an ammeter. After reaching the nominal values, the service tube is sealed.
Why can’t you just add freon?
If there was air in the system, simple refilling will not help. Oxygen will react with the oil, forming an acid that will corrode the compressor from the inside in a couple of months.
Frequently asked questions (FAQ)
Is it possible to replace a compressor without soldering?
There are so-called piercing valves and couplings, but their use is considered temporary measure. For reliable and durable operation of the refrigerator, hard soldering is necessary, ensuring complete tightness of the circuit.
How much does it cost to replace a compressor with a specialist?
The cost consists of the price of a new motor, the cost of the refrigerant and the work of a specialist. On average, this is a significant part of the price of a new refrigerator, so it is often more advisable to think about buying new equipment if the old one is more than 10 years old.
Why does a new compressor get hotter than the old one?
Modern motors often operate at higher housing temperatures for energy efficiency purposes. However, if only the upper part heats up or a knocking sound is heard, this may indicate a defect or incorrect installation.
Does the system need to be flushed when replacing the motor?
If the old compressor burned out (“clogged” or short-circuited), carbon or acidic residues could remain in the system. In such cases, professionals recommend purging the system with nitrogen or installing a filter drier to protect the new unit.