The situation when you open the refrigerator door and see a light on, but there is room temperature inside, always causes panic. Food begins to spoil, there is a risk of a huge supply of food defrosting, and thoughts about expensive repairs are swarming in your head. However, the presence of light indicates that electrical network it is working, the socket is working, and voltage is supplied to the device. This is already half the solution to the problem, as it narrows the scope of troubleshooting.
Modern refrigerators, be it Indesit, LG, Atlant or Bosch, are designed on a similar principle, although they have their own design features. Failure of the cooling system when the lighting is running most often indicates a breakdown of one of the key components of the refrigerant circulation cycle or control system. Diagnostics It begins with analyzing the sounds that the unit makes and checking the temperatures in different chambers.
You should not immediately call a technician if you are not confident in your abilities, but An initial visual and auditory assessment is necessary. This will help the service manager more accurately give the preliminary cost of the work or even suggest a solution over the phone. In some cases, the reason lies in a banal electronics failure or improper operation, and not in a serious breakdown.
Primary diagnosis: listen and watch
The first thing you need to pay attention to is the sound of the compressor. If, when the door is open, you do not hear a characteristic hum, vibration or start click, it means that the motor is not receiving a start command or cannot start. In this case, the light is on because the lighting circuit is independent of the engine circuit, but the unit itself is “sleeping.”
The opposite situation, when the motor hums, but there is no cold, indicates problems with freon circulation or the operation of the fan. If the hum is intermittent, followed by clicks and attempts to start, which immediately stop, this is a sure sign of a malfunction of the start relay or the compressor itself. In modern models with the system No Frost it is also important to listen to the operation of the blower fan.
It is important to check whether air access is blocked. If food is placed close to the back wall or the ventilation holes are covered, the cold simply does not spread throughout the chamber. In such cases, thermostat may assume that the temperature is normal (if the sensor is located in a different place), and not turn on the compressor, or vice versa, the motor runs without stopping, but there is no effect due to circulation problems.
⚠️ Attention: If you smell burning or see sparking in the area of the compressor or wiring, immediately disconnect the device from networks. Further operation may lead to a fire or complete failure of the electronics.
Problems with the thermostat and temperature sensors
One of the most common reasons why the refrigerator stopped freezing is the exit from building thermostat (in mechanical models) or temperature sensor (in electronic ones). These elements are responsible for controlling the cold inside the chamber. If the thermostat is “stuck” in the “off” position or its contacts are oxidized, the command to start the compressor is simply not received, although there is electricity in the network.
In models with electronic control, control moduleis responsible for all processes, which reads readings from several sensors. If one of the sensors is lying or its circuit is broken, the control unit may go into protective mode or mistakenly believe that it is already cold enough in the chamber. Often in such cases, an alarm indication lights up on the display, but not always.
Checking the thermostat in mechanical refrigerators is possible at home. To do this, you need to find its location (usually inside the camera or outside on the body), remove the adjustment knobs and carefully remove the device. By ringing the contacts with a tester at different temperatures (cooling and heating), you can understand whether the circuit is closed. If the contacts do not respond to cold, the part requires replacement.
How to temporarily start a refrigerator with a faulty thermostat?
If the thermostat is mechanical and does not close the circuit, you can carefully close its contacts with a wire to test the compressor. But remember: this is a temporary measure! The refrigerator will freeze uncontrollably until you turn it off manually. Prolonged operation without a thermostat will lead to freezing of the evaporator and damage to the compressor.
Replacing sensors in electronic systems requires disassembling the inner lining of the chamber, which is not always convenient to do without experience. A sensor error often results in the compressor either not turning on at all or running without stopping, causing freezing products or, conversely, complete defrosting.
Malfunctions of the start relay and compressor
If the light is on, but the compressor is silent or makes short clicks, the problem may lie in start-up protection relay. This small device, placed on the motor housing, is responsible for starting the engine and protecting it from overloads. Inside the relay there is a coil and contacts that can burn or stick over time.
When the relay fails, the motor tries to start, hums for a few seconds, then there is a click and it goes silent. After some time, the cycle repeats. In this mode of operation compressor it will not last long, so you cannot operate the refrigerator in this condition. Replacing the relay is an inexpensive procedure and is often performed independently.
The most serious and expensive breakdown is the combustion of the compressor windings or its mechanical wear (wedge). If the motor hums, but does not start, and at the same time gets very hot, an interturn short circuit may have occurred. In this case, it is necessary replacing the compressorwhich requires calling a technician with equipment to evacuate the system and refill with freon.
- 🔌 Checking the relay: Remove the relay, shake it. If a ringing sound is heard inside (as if from broken glass), it means that the posistor or contacts are damaged and need to be replaced.
- 🌡️ Case temperature: When the compressor is running, its housing should be hot. If the motor is cold and does not hum, the problem is in the electrics or relay.
- ⚡ Current strength: Professionals check the strength of the starting current. If it is below normal, the winding may be broken.
Freon leakage and blockage of the capillary system
When the compressor operates continuously, hums, but there is no cold, and the condenser (grid at the back) remains only partially cold or warm, there is a high probability refrigerant leaks. Freon is a substance that circulates through the system, picking up heat. If it is absent or small, heat exchange does not occur and the temperature in the chamber does not drop.
Leaks often occur in places where tubes are soldered, in the foamed part of the housing (evaporator) or in the condenser due to corrosion. It is difficult to notice a leak visually; sometimes you can see oily spots on the tubes - these are traces of oil that comes out along with the gas. Diagnostics requires the use of a leak detector or soap solution, but often the leak site is hidden in the insulation.
Another reason - Clogged capillary tube. The circulation system has a very thin tube that can become clogged with oil breakdown products or moisture (when moisture freezes, an ice plug forms). If clogged, freon cannot circulate, the pressure in the system drops, and the cooling capacity disappears. In this case, the compressor also works without stopping.
| Symptom | Probable cause | Nature of motor operation | Temperature condenser |
|---|---|---|---|
| The refrigerator does not freeze | Freon leakage | Works without stopping | Cold or barely warm |
| No cold, you can hear gurgling | Clogged capillary | Works without stopping | Hot only at the outlet |
| Periodic on/off | Thermostat malfunction | Rarely turns on or does not turn on | Complies with operating cycles |
| Buzzes and clicks | Failure of the relay/compressor | Start attempts | Does not heat up |
Failures in the No Frost system and fan operation
In refrigerators with the system No Frost cold is generated in one compartment (usually the freezer) and distributed by a fan throughout the entire volume. If you hear that the compressor is running, but the main chamber is warm, and the freezer is cold little or not at all, the fan may not be working. The reasons for the fan stopping can be different: freezing of the blades due to frozen ice, a breakdown of the fan motor or broken wiring. Some models have a defrost sensor that blocks the fan if sludge has formed on the evaporator. Also, the fan motor itself often fails. Another problem with the system is a malfunction of the defrost system. If the defrost heating element, timer or defrost sensor breaks, the evaporator becomes covered with ice. Ice blocks the air supply channels, and the cold stops flowing into the chambers. From the outside it may look like a running refrigerator (the motor is humming), but inside it is warm. After some time, the ice may melt and water will flow onto the floor. fan.
The reasons for a fan stopping can be different: freezing of the blades due to frozen ice, breakdown of the fan motor or broken wiring. Some models have a defrost sensor that blocks the fan if sludge has formed on the evaporator. It also often fails on its own. fan motor.
Another problem with the system No Frost — malfunction of the defrost system. If the defrost heating element, timer or defrost sensor breaks, the evaporator becomes covered with ice. Ice blocks the air supply channels, and the cold stops flowing into the chambers. From the outside it may look like a running refrigerator (the motor is humming), but inside it is warm. After some time, the ice may melt and water will flow onto the floor.
- ❄️ Ice: Check the back wall of the freezer. If it is covered with a thick layer of ice or a snow coat, the defrosting system does not work.
- 🌀 Air sound: If the system is working properly, you should hear a slight noise of escaping air. If there is silence, the fan is stopped.
- 🧊 Defrosting: Try to defrost the refrigerator completely (24 hours). If it starts working after turning it on, there is a problem in the defrosting system.
⚠️ Attention: Do not try to pick out the ice with a knife or sharp objects! You can damage the evaporator, which will lead to an instant leak of freon and expensive repairs with welding.
Electronic control module and wiring
In modern models, the "brain" is electronic control module. If it fails, the refrigerator may behave unpredictably: the light is on, the display may light up (or go out), but no cooling commands are received. The cause may be power surges, moisture or manufacturing defects.
Often the problem lies not in the board itself, but in oxidation of contacts or broken wires. Vibration during compressor operation over time leads to chafing of wires or loosening of connections in connectors. This is especially true for wires going to door sensors and thermostats.
Diagnostics of the module requires special knowledge and equipment. You can visually inspect the board for burnt tracks, swollen capacitors, or traces of burning. However, even if the board looks intact, this does not guarantee its serviceability. Often a flashing or replacement of the entire assembly is required.
☑️ Actions if electronics are suspected
Frequently asked questions (FAQ)
Is it possible to store products in a non-working refrigerator, if it simply does not freeze?
It is strictly not recommended. If the temperature inside rises above +5...+6°C, active proliferation of bacteria begins. Products may look normal but become hazardous to health. It is better to move them to another place or use them to a minimum.
How long does it take to defrost the refrigerator to check the No Frost system?
It takes at least 24 hours for the ice in the hidden channels and on the evaporator to completely thaw. Defrosting for 2-3 hours is often insufficient, and after turning on the problem returns within a day.
Why did the refrigerator start working after defrosting, but after a week it stopped again?
This is a classic sign of a malfunction of the defrosting system (the heating element, timer or sensor burned out). Ice had accumulated again and blocked the air passages. Replacement of faulty elements of the defrost system is required.
Is it dangerous to change the starting relay yourself?
Replacing the relay is safe if you have disconnected the device from the network. This is a mechanical procedure: take off the old, put on the new. The main thing is to choose a relay with exactly the same markings as the original.
What to do if the compressor is hot, but does not start?
Most likely, the thermal protection has tripped or the compressor has jammed. Let it cool (several hours). If, after cooling down, when turned on, there is a buzzing and clicking sound again without starting, call a technician; the compressor is likely to be replaced.