The sudden defrosting of food or the appearance of puddles under the refrigerator often takes people by surprise, causing them to panic. First of all, the owner of the equipment begins to listen to the unit, trying to understand whether the engine is running. Compressor It is the heart of the cooling system, and the safety of your food supply depends on its serviceability.
Understanding the operating principle and the ability to carry out initial diagnostics will help avoid unnecessary calls to the technician or, conversely, They will tell you that it is no longer possible to delay the repairs. In this article we will analyze all the available testing methods: from simple listening to the use of measuring instruments.
Modern models of refrigerators, be it Indesit, Bosch or LG, can operate almost silently thanks to inverter technology. Therefore, the absence of the usual buzzing does not always mean a breakdown, but this fact cannot be ignored.
Visual and auditory primary diagnostics
The first thing to do is go to the refrigerator and listen carefully. A working engine emits a smooth, low-frequency hum, which can be interrupted by the characteristic gurgling of refrigerant in the tubes. If the unit is silent and the chamber is warm, this is the first alarm signal.
However, silence can also be caused by the operation of electronics, which temporarily turned off the motor. In modern models with the system No Frost pauses between cycles can be quite long. Try placing your hand on the side wall or rear grille - if they are warm, then the cooling cycle has recently completed or is currently underway.
⚠️ Attention: If you hear a loud click, after which the engine tries to start, hums for a couple of seconds and clicks again, going silent - this is a sign of a malfunction of the start relay or the compressor itself. You cannot operate the equipment in this mode.
You should also pay attention to the indication on the display (if there is one). Many brands, such as Samsung or Electrolux, display error codes that directly indicate problems with the motor or temperature sensors.
Checking the thermostat and electrical circuit
Before sinning on an expensive one motor-compressor, it is necessary to exclude simpler reasons for its downtime. Often the problem lies in the control chain, which simply does not send a signal to start. The thermostat or electronic control module may be faulty.
First, check whether voltage is supplied to the outlet. It's a cliché, but often overlooked. If everything is in order with the socket, you can try to force the system to start by closing the thermostat contacts (in mechanical models). To do this, you need to remove the plastic handle of the regulator and carefully connect the wires going to it.
If after this manipulation the engine hums, then the problem was in the temperature sensor. If there is no reaction, the diagnosis continues deeper.
- 🔌 Check the integrity of the power cord and plug for melting.
- 🌡️ Make sure that the thermostat is not in the "Off" or "0" position.
- 💡 Inspect the light bulb inside: if it does not light up when opening the door, there may be a problem with the power supply to the entire refrigerator.
Diagnostics of the starting relay and engine protection
One of the most common reasons why compressor does not start is the failure of the starting relay. This small element is responsible for supplying a starting pulse to the motor winding. If the relay is “stuck” or burnt out, the motor will only hum or click quietly.
To check the relay, you need to remove the rear protective cover at the bottom of the refrigerator. There you will see a black cylindrical or rectangular element placed over the contacts of the compressor. Carefully remove it and shake it near your ear. If a ringing or knocking sound is heard inside, it means that the mechanical part is damaged and requires replacement.
It is also worth inspecting the contacts for carbon deposits or oxidation. In models Atlant and Stinol there are often relays that can be replaced without soldering, simply choosing an analogue according to the marking.
☑️ Checking the start relay
Do not forget about the thermal protection relay, which is often paired with a starting one. It opens the circuit when the windings overheat. If the compressor housing is hot and the relay is cold, perhaps it is the protection that is blocking the start.
Using a multimeter for an accurate check
For those who are friendly with technology, the most accurate diagnostic method is to test the windings motor with a multimeter. This method allows you to determine with a high degree of probability whether the motor is alive or has an open/short circuit.
First you need to remove the starting and thermal relay to gain access to the three contacts on the compressor. Switch the multimeter to resistance (ohms) measurement mode. Sequentially measure the resistance between each pair of contacts. Normal values usually range from 10–30 Ohms for the starting winding and 15–45 Ohms for the working winding.
If the device shows one (infinity) or zero, this indicates an open or short circuit. It is also critical to check the resistance between any pin and the copper tube or housing (to ground). Here the device should show infinity.
| Measurement parameter | Normal value | Symptom of malfunction |
|---|---|---|
| Starting winding resistance | 10 - 30 Ohm | Open (∞) or short circuit (0) |
| Resistance of the working winding | 15 - 45 Ohm | Open (∞) or short circuit (0) |
| Resistance to the body (ground) | Infinity (∞) | Any value (insulation breakdown) |
| Starting current (if current clamps are present) | Depends on the model (usually 3-6 A) | Significantly higher than normal |
⚠️ Attention: If you find a breakdown in the housing (the resistance between the contacts and the pipe is not infinite), further operation of the refrigerator is deadly! Such a unit can produce an electric shock through metal objects or the floor.
Analysis of the operation of inverter compressors
Owners of modern refrigerators LG, Samsung or Beko with inverter motors may encounter diagnostic difficulties. These units do not make the usual clicks when starting and stopping, since they do not turn off completely, but only change the rotation speed.
An inverter compressor can operate at very low speeds, creating a barely audible noise that is easy to miss in the background of the operation of household appliances. To understand whether it is working, place your hand on the side wall inside the chamber or on the grille at the back - you should feel a slight vibration and warmth.
Diagnostics of inverters with a multimeter in ohmmeter mode is often impossible, since they have three-phase motors with electronic control. The check is carried out through the self-diagnosis menu (combinations of buttons on the panel) or by measuring the voltage at the output of the inverter board.
If a refrigerator with an inverter stops cooling, and the diagnostics show an error in the control module, most likely the problem is in the inverter board or the temperature sensor itself, and not in the mechanical part of the motor.
Typical symptoms and table malfunctions
Summarizing the above, we can highlight the main scenarios for the behavior of the refrigerator that will help you navigate the situation. Silence does not always mean the death of the motor, and a hum does not always indicate its operation.
It is important to distinguish the nature of the sound. A steady hum is normal. Metallic clanging, whistling, or intermittent buzzing sounds are signs of mechanical failure or electrical problems.
The following is a table to help classify symptoms and suspected causes:
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| Silent, no light | No power in the socket, broken cord | Low |
| Clicks, but does not start | The starting relay is faulty or the piston is jammed | Medium / High |
| Humming constantly, without turning off | Freon leak, compressor wear, door not closing tightly | High |
| Works jerkily | Problems with the thermostat or control board | Medium |
If you observe a situation where the motor is running, but there is no cold, this may indicate a refrigerant leak or clogged capillary tube. In this case, the compressor itself compressor may be in good order, but the system needs to be refilled and cleaned.
When you need to call a technician
Independent diagnostics are good for understanding the scale of the problem, but do not always lead to successful repairs. If you find that the compressor is “broken” to the housing or there is no freon in the system, further actions require special equipment and licenses.
Replacing a compressor is a complex process that includes cutting copper tubes, soldering with new solder, creating a vacuum in the system and accurately charging the refrigerant. Without a vacuum pump and scales for freon, it is impossible to perform this work efficiently.
⚠️ Attention: Trying to replace the compressor yourself without the appropriate tools often leads to the new motor burning out after a few months due to residual moisture in the system or incorrect dosage of oil.
It is also worth contacting professionals if we are talking about complex electronic control boards in models Whirlpool or Haier. Diagnosing electronics requires circuitry and experience, and the cost of error is high.
In conclusion, regular refrigerator maintenance, including defrosting (if not automatic) and cleaning the condenser at the back, will extend the life of the compressor. Monitor the room temperature and do not place the refrigerator close to the wall to ensure proper ventilation.
Why is the compressor hot, but the refrigerator does not freeze?
This is a classic sign of a freon leak or a clogged capillary system. The compressor tries to pump gas, but there is no refrigerant circulation, so the heat is not removed, and the motor idles and overheats.
Is it possible to replace the compressor with an analogue of a different brand?
Theoretically, it is possible if the mounting dimensions, power and type of refrigerant are the same. However, it is better to install original spare parts or certified analogs recommended by the manufacturer of your model, for example, for Indesit compressors are often suitable. Aspera.
How long does a compressor last in a refrigerator on average?
The average service life of a high-quality compressor is 10–15 years. Inverter models can operate for up to 20 years or more due to the absence of constant starting loads.
Is it dangerous to repair a refrigerator yourself?
Yes, it is dangerous. Risks include electric shock (220V), soldering burns, and the possibility of refrigerant poisoning if the system is not opened carefully. The mechanical part of the compressor is under high pressure.