A sudden stop in the operation of household appliances often becomes an unpleasant surprise, especially when perishable goods remain in the chamber products. Refrigerator is a complex unit in which electrical, mechanical and thermodynamic processes are interconnected. Understanding which components are subject to wear will help you quickly navigate the situation and make the right decision about calling a technician or doing it yourself.
Statistics from service centers show that most breakdowns can be predicted by characteristic sounds or changes in the operation of the system. Compressor, thermostat, The evaporator and defrost system are the main elements that require attention. Ignoring primary symptoms, such as rare engine starts or the appearance of ice, often leads to costly restoration of the unit.
In this article we will analyze in detail the main types of malfunctions, their causes and diagnostic methods. You will learn to distinguish simple problems that can be solved in five minutes from complex technical failures that require the intervention of professionals.
Temperature violations and cooling problems
The most obvious and alarming problem is the lack of cold in the cells. If you notice that food in main compartment or the freezer has begun to deteriorate, first check the thermostat settings. Sometimes users accidentally set the mode to minimum, thinking that the equipment is faulty. However, if the regulator is positioned correctly, but there is no cold, the reason lies deeper.
A frequent cause of insufficient cooling is refrigerant leak (freon). In normal condition, the system is sealed, and gas circulates around the circuit for years. But metal corrosion, vibration or manufacturing defects can lead to microcracks. If there is a freon leak, the compressor can work continuously, trying to gain temperature, but cold is not produced. This is a critical moment, since prolonged operation of the engine for wear and tear without stopping can lead to its combustion.
Another scenario is the formation of a “snow coat” or ice plugs in the cold exhaust channel. This is typical for systems No Frostwhere the defrost cycle is broken. The defrost heating element may have burned out, or the temperature sensor has failed, causing the evaporator to become overgrown with ice and stop passing air into the chamber.
⚠️ Attention: If you hear a hissing sound when opening the door or see oily spots under the unit, this may indicate a violation of the tightness of the circuit. Do not try to seal the tubes yourself - professional sealing and vacuuming of the system is required.
Diagnostics of temperature problems often requires measuring the pressure in the system and checking the tightness of the circuit using special equipment. You can only visually inspect the back wall yourself and listen to the operation of the motor.
Malfunctions of the compressor and start relay
The heart of any refrigerator is compressor. It is this that creates the pressure necessary for the circulation of the refrigerant. If the motor hums but does not start, or, conversely, turns on for a couple of seconds and clicks when it turns off, the problem most often lies in the start-protection relay. This device protects the motor windings from overloads and helps it start.
When the relay fails, the contacts burn out and the current stops flowing to the starting winding. As a result, the compressor hums, trying to move, but the thermal release opens the circuit. Replacing a relay is a relatively simple procedure, accessible even to beginners, if you know the model of your unit, for example Indesit or Atlant.
A more serious situation is an interturn short circuit in the windings of the compressor itself or its mechanical wear. In this case, the unit may become very hot, make a metallic knock, or operate with increased noise levels. Repairing such a unit is not economically feasible; usually a complete replacement of the compressor is required.
- 🔊 Humming without starting: a sign of a faulty start relay or jammed piston group.
- 🔥 Extreme heating of the case: indicates motor overload or problems with condenser ventilation.
- ⚡ Knocking out plugs: short circuit in the wiring or breakdown of the winding on the case.
- 🔄 Cyclic operation: the motor turns on and immediately turns off - a symptom of burning out the starting winding.
Before changing it, it is necessary to exclude other causes, such as power surges or a malfunction of the thermostat.
Problems with the defrost system and ice freezing
In refrigerators with the system No Frost ice should not form in the visible part of the chamber. If you see freezing, it means that the evaporator defrost process is disrupted. The system consists of several key elements: a timer (or electronic module), a defrost heating element, a defrost sensor and an evaporator temperature sensor.
Most often it burns out itself Defrost heating element. It is a tube or coil that heats up at certain intervals, melting the ice on the evaporator. You can check its integrity with a multimeter - the resistance should be in a certain range. If the circuit is broken, the ice does not melt, the channels become clogged, and the cold stops flowing into the chamber.
The defrost sensor (defrost) also often fails. It should open the heating element circuit when the ice has completely melted. If it is “stuck” in the open state, the heating element will never turn on. If it does not open the circuit, the heating element will heat constantly, which can lead to food spoilage.
⚠️ Attention: When defrosting the refrigerator manually, never use sharp objects to chip ice. Damage to the evaporator will lead to an immediate leak of freon and expensive repairs.
Sometimes the problem lies in a clogged drain hole. Water from melted ice should drain into a special container on the compressor. If the tube is clogged with debris or mold, water accumulates and freezes, forming an ice plug.
☑️ Diagnostics of the No Frost system
Malfunctions of the thermostat and sensors
The thermostat (thermostat) is the “brain” that decides when to turn on and when to turn off the compressor. In older models this is a mechanical device with a bellows, in new ones there are electronic sensors (NTC thermistors). If the thermostat is faulty, the refrigerator may either not turn on at all or work without interruption, freezing all contents.
Signs of a breakdown of a mechanical thermostat are often expressed in the absence of a characteristic click when turning the knob. There may also be a situation where the chamber does not cool down enough, but the motor does not start. In electronic models, sensor failure is usually indicated by an error code on the display, for example F1 or E2.
Replacing the thermostat requires care. The capillary tube of a mechanical sensor must not be kinked or damaged, otherwise the coolant inside it will escape and the device will stop responding to temperature. Electronic sensors are often changed in pairs, as their readings may diverge over time.
| Symptom | Probable cause | Action |
|---|---|---|
| The refrigerator does not turn on | The thermostat or sensor is faulty | Close the contacts to check |
| Works without stopping | Freon leakage or thermostat sticking | Check the pressure and replace the sensor |
| Severe hypothermia | Thermostat contacts are stuck | Replacing the thermostat |
| Short operating cycle | Incorrect calibration or leakage | Configuring or diagnosing the circuit |
For diagnostics, the exclusion method is often used: they temporarily connect a working sensor or close the circuit, observing the reaction of the compressor. This helps to determine exactly where the breakdown lies.
How to check a mechanical thermostat?
To check a mechanical thermostat, it must be removed from the housing. Immerse the sensing tube in ice water for 2-3 minutes. Then test the contacts with a multimeter. If the device is working properly, when cooling the contacts should open (or close, depending on the type), making a click. If there is no reaction, the part needs to be replaced.
Extraneous sounds and vibration during operation
The refrigerator should not be absolutely silent, but the nature of the sounds matters. A smooth hum of the compressor and a quiet sound of freon flowing through the tubes (gurgling) is considered normal. However, the appearance of knocking, grinding or whistling indicates problems.
The compressor itself can produce a loud knock if its internal suspensions or bearings have collapsed. It can also knock fan in the No Frost system if ice has frozen on its blades or dust has gotten into the bearing. A grinding sound often indicates that the circuit tubes are touching each other or the housing, transmitting vibration.
If the refrigerator begins to vibrate more than usual, check the installation of the legs. The unit must stand strictly horizontally. Sometimes vibration is caused by an incorrectly installed condenser grille at the rear or loose motor mounting bolts.
- 🔨 Metal clanging: often occurs when starting the compressor, a sign of wear on the motor suspension.
- 💨 Whistling: may indicate a freon leak through a microcrack under pressure.
- 🌀 Fan noise: icing or wear of the evaporator fan bearing.
- 📢 Humming: normal operating sound, if it has not become louder and sharper than usual.
Some sounds may be temporary. For example, after defrosting or first installation, the refrigerator may make more noise until the system returns to operating mode. But if the noise increases, you cannot ignore it.
⚠️ Attention: If you hear a sharp whistle, immediately unplug the device and ventilate the room. Although modern refrigerants are less toxic, the concentration of gas in a confined space with a large leak is undesirable.
Electrical faults and wiring problems
Modern refrigerators are full of electronics that are sensitive to voltage changes. Network surges can damage the control module (board) that controls all processes. Symptoms of board failure are varied: indicators do not light up, buttons do not respond, systems turn on and off chaotically.
Often the problem lies not in the board itself, but in the oxidation of the contacts. In high humidity environments (especially in the kitchen), the terminals can oxidize, causing poor contact. This leads to heating of the wiring, melting of the insulation and even a short circuit. Inspect the plug, socket and internal connections.
Also worth mentioning is the wiring problem inside the door. In two-chamber models, the wires to the light bulb and door sensor pass through the hinge. When the door is opened frequently, the wires break, which leads to the light not coming on or the control module “thinking” that the door is open and not starting the compressor.
A multimeter is needed to diagnose electrical circuits. The test begins with continuity of the power cord, then checks the integrity of the fuses on the board and the presence of voltage at the input to the control module.
Why does the refrigerator turn on and immediately turn off?
This could be caused by a tripped thermal compressor protection relay due to overheating, a faulty start relay, or a short circuit in the windings. Also, the cause may be a faulty thermostat, which gives an incorrect shutdown signal.
Is it possible to operate a refrigerator with a cracked shelf?
Technically it is possible, but it is unsafe. Glass can burst completely under stress and vibration, damaging food and internal components. In addition, a violation of the seal of the chamber (if the crack is through) will lead to moisture ingress and a violation of the temperature regime.
How often do you need to defrost a No Frost refrigerator?
The No Frost system does not require manual defrosting to remove ice, as this happens automatically. However, it is recommended to completely turn off the appliance at least once a year, wash and dry it to remove bacteria and check the drainage system.
What to do if there is a burning smell in the refrigerator?
Immediately unplug the appliance. A burning smell indicates overheating of the wiring, melting of the insulation or combustion of the motor winding. Operating in this condition may result in a fire. A technician needs to be called to inspect the electrical part.