A sudden failure of refrigeration equipment always takes people by surprise, because it threatens damage to a large supply of food. When the unit stops freezing, makes strange sounds, or becomes covered with an ice crust, the owner needs to quickly navigate the situation. Initial self-diagnosis helps to understand the scale of the problem: whether an urgent call to a technician is required or whether the failure can be fixed on your own.
Modern models, be it Indesit, LG or Atlant, are equipped with complex electronics, but the basic principles of operation of the compressor and refrigerant remain unchanged. Understanding these processes allows you to avoid panic and unnecessary spending. In this article, we will analyze the main symptoms of malfunctions, methods for checking them and the tools that will be needed for accurate diagnosis.
Before starting disassembly, it is important to evaluate external signs: whether the light is on inside, whether the fan is working, whether there are puddles under the device. Initial visual inspection often provides more information than complex measurements. Ignoring simple steps can lead to aggravation of the breakdown, so act consistently and carefully.
Visual diagnostics and analysis of external signs
The first stage of troubleshooting should always be a thorough inspection without the use of tools. Pay attention to the condition of the rear wall where the capacitor is located. If the grill is black and hot, this is normal for a running compressor, but if it is icy or, conversely, at room temperature when the engine is running, this is a signal of a problem.
Check the rubber seals on the doors. Often the reason The refrigerator does not maintain temperaturelies in the loose fit of the door. The test with a sheet of paper is simple: press the sheet between the door and the frame around the entire perimeter. If the paper falls out or is pulled out without resistance, the seal requires replacement or adjustment of the hinges.
⚠️ Attention: If you find oily stains under the refrigerator or on the floor next to it, immediately unplug the appliance. This may indicate a leak of freon along with oil, which requires professional intervention.
Inspect the interior of the chambers for swelling of the back wall or the appearance of a “snow coat” in certain places. Localized ice formation often indicates problems with the defrost system or a clogged capillary tube. A uniform layer of frost throughout the evaporator is a sign of normal operation, while ice build-ups in one corner are a pathology.
Checking the electrical circuit and start relay
If the refrigerator is silent and does not make any sounds, there is a problem may be due to lack of power or failure of the start relay. First, make sure there is power in the outlet by connecting another device to it. If the network is working properly, but the equipment does not respond, you should check the integrity of the power cord and plug.
The starting relay is a small unit that supplies an impulse to start the compressor motor. If it breaks down, the compressor may hum, trying to start, but after a few seconds click and turn off. To check, remove the back cover, find the relay next to the compressor and gently shake it.
- 🔊 If a ringing or knocking sound is heard inside the relay, it means that the internal contact group is damaged and requires replacement.
- 🔌 Check the contacts for oxidation or melting - this is a common cause of a poor connection.
- 🧪 Test the windings with a multimeter: the resistance should be within the normal range specified in the technical documentation.
Replacing a relay is one of the simplest operations in repairing household appliances. However, it is important to select an exact copy of the part, since they differ in the type of compressor and power. An incorrectly selected relay can lead to rapid combustion of the motor windings.
Diagnostics of the thermostat and sensors temperature
The thermostat (thermostat) is responsible for turning the compressor on and off depending on the temperature inside the chamber. If the refrigerator runs continuously without turning off, or, conversely, does not start at all, this is the unit that needs to be suspected first. Modern electronically controlled models use air sensors instead of a mechanical thermostat.
To check the mechanical thermostat, it must be removed from the chamber (usually it is located under a plastic panel or inside the lamp shade). The thermostat contacts should close when the temperature drops. You can check this with a multimeter in continuity mode: when cooling (for example, by putting the sensor in the freezer for 15 minutes), the circuit should open or close depending on the design.
In models with the system No Frost defrost sensors often fail. If the evaporator is covered in ice and the fan is not blowing cold air, the sensor may “think” that defrosting is still in progress and prevents the compressor from starting. The electronic control module reads the readings of these sensors and blocks operation in case of discrepancies.
| Symptom | Probable cause | Check method |
|---|---|---|
| The refrigerator does not turn off | Faulty thermostat or freon leak | Close the thermostat contacts directly |
| The compressor does not start | Open circuit of the thermostat | Ring the contacts with a multimeter |
| Frequent on/off | Incorrect sensor calibration | Compare readings with a real thermometer |
| Error on display | Faulty air sensor | Check sensor resistance |
☑️ Checking the thermostat
Analysis of the operation of the compressor and motor
The compressor is the heart of the refrigerator, creating pressure for the circulation of the refrigerant. If the motor hums but does not start, or starts for a couple of seconds and stalls, the problem may be in the motor itself or in the starting winding. Overheating of the compressor housing (when it is impossible to touch it) indicates an overload or an interturn short circuit.
You can determine the condition of the windings by measuring the resistance between the contacts on the terminal block. The normal resistance of the working winding is usually 10-30 Ohms, the starting winding is 20-50 Ohms, and between the case and the windings the resistance should be infinite (for breakdown). If the multimeter shows zero or very low resistance between the winding and the housing, the compressor is broken into the housing and requires replacement.
⚠️ Attention: An attempt to start a faulty compressor directly, bypassing the relay, can lead to a short circuit and fire. Do not experiment with applying voltage to the windings without the appropriate skills.
It is also worth paying attention to the noise level. A dull hum is normal, but a metallic knock, rattle or vibration transmitted to the housing indicates mechanical wear of the internal parts of the motor. In such cases, repairs are often not economically feasible, and the installation of a new unit is required.
Is it possible to replace the compressor yourself?
Theoretically, yes, but this requires special equipment: a vacuum pump for pumping out the system, a torch for soldering copper tubes and a pressure gauge station for charging freon. Without these tools and skills, the sealing of the system will be broken, and the refrigerator will not work.
Searching for freon leaks and problems with the defrost system
If the compressor runs constantly, but there is no cold, or only partial ice is visible on the evaporator, there is a high probability of a refrigerant leak. Freon is odorless and colorless, so it is difficult to detect visually. Leaks often occur in places where tubes are soldered or in the foamed part of the body due to corrosion.
Defrosting system in refrigerators No Frost includes a heating element (heater), a timer or electronic module, and sensors. If the heating element is burnt out, the ice does not melt, the drainage hole becomes clogged, and the air stops circulating. You can check the heating element by dialing: if the resistance is infinite, the heating element has burned out.
- ❄️ Check the drainage hole: if the water does not go into the tray above the compressor, clean the channel with soft wire or a syringe with warm water.
- 🔥 Measure the resistance of the defrosting heating element - it should be in the range 200-400 Ohm.
- ⏱ Make sure that the defrost timer switches modes (for mechanical models).
It is important to note that a complete loss of freon requires not only searching for the leak, but also evacuation of the system before refilling.. You cannot simply “add” gas, since air and moisture will remain in the system, which will quickly damage the compressor. Therefore, if a leak is suspected, calling a technician is required.
Electronic errors and fault codes
Modern refrigerators are equipped with a self-diagnosis system. When a fault is detected, an error code appears on the display or the temperature indicator flashes. Deciphering these codes can significantly reduce the troubleshooting time. For example, code “Er FF” indicates a fan motor error, and code code “22E” indicates a communication problem between the main and display module. LG The "Er FF" code indicates a fan motor error, and the Samsung “22E” - to the problem of communication between the main and display module.
To access the service menu, sometimes you need to press a certain combination of buttons (for example, hold down “Freeze” and “Fridge” simultaneously for 5 seconds). In the service mode, you can see the current sensor readings in real time, which helps to identify “floating” faults that do not appear constantly.
Resetting the error does not always eliminate the cause. If the control module detects a critical failure, it can block the operation of the compressor until the failure is repaired. A reboot (disconnect from the network for 15 minutes) can only help in case of a software failure, but not a mechanical failure.
Frequently asked questions (FAQ)
Why does the refrigerator hum but not freeze?
Most often this indicates a freon leak or a clogged capillary tube. The compressor idles, trying to build up pressure, but the refrigerant is not circulating. It is also possible that the compressor itself may break down when it does not create enough pressure.
Is it possible to operate the refrigerator if the thermostat is broken?
For a short time - yes, if you close the contacts directly. However, in this case, the refrigerator will operate continuously, which will lead to deep freezing of food and icing of the chamber, as well as overloading the compressor. This is a temporary solution until you purchase a new part.
What to do if water appears inside the refrigerator?
First of all, check the drainage hole on the back wall. It could become clogged with crumbs or ice. Clean it with a special brush or soft wire. If there is water outside under the refrigerator, check the integrity of the water evaporation tray above the compressor.
How often should you defrost the refrigerator?
Models with manual defrosting require shutdown every 4-6 months when a layer of ice 5 mm thick forms. Systems No Frost i Full No Frost do not require manual defrosting, but preventive washing is recommended 1-2 times a year.