The situation when the refrigerator defrosts by itself always takes you by surprise. You open the door, and instead of the usual cold you feel warm, and the food begins to melt. This is not just discomfort, it is a direct threat of spoilage of food supplies. Why is this happening? Most often, the problem lies in the malfunction of the main components of the unit, such as the compressor, thermostat or heat removal system.
Do not panic ahead of time. Sometimes the reason is trivial and lies in improper operation or a minor malfunction that you can fix yourself. However, in some cases, the intervention of a professional with equipment for refilling freon is required. In this article we will analyze in detail all the possible reasons why the refrigerator stops freezingand tell you what to do first.
It is important to understand that ignoring the first signs of a malfunction can lead to expensive repairs. If you notice that frost has disappeared on the walls of the chamber and the products have become soft, you need to carry out diagnostics. We will consider both simple everyday errors and complex technical breakdowns typical of modern models Indesit, LG and Bosch.
Faults of the thermostat and temperature sensors
One of the most common reasons why the refrigerator defrosts is the failure of the thermostat. This component is responsible for maintaining the set temperature inside the chambers. If thermostat is broken, it may not send a signal to the compressor to turn on, and the unit simply stands idle. As a result, the temperature gradually increases, and the defrosting process begins.
In models with electronic control, air sensors are used instead of a mechanical thermostat. Their task is to read the temperature and transmit data to the control module. If the sensor “lies” or its circuit is broken, the system may “think” that the cold is sufficient and does not start the cooling cycle. Checking these elements requires a multimeter and certain skills.
Symptoms of a malfunctioning thermostat often appear cyclically: the refrigerator can be silent for a long time, and then suddenly work at full capacity, or vice versa. In some cases, simply adjusting the thermostat knob helps, but if this does not help, the part must be replaced.
You can follow a simple procedure to diagnose a mechanical thermostat. You need to remove the regulator handle and carefully remove the bellows tube from the chamber. If a click is heard when placing the tube in the cold (for example, in the freezer for 15 minutes), it means that the device is working. The absence of a click indicates the need for replacement.
Problems with the compressor and start relay
The heart of any refrigerator is the compressor. It is he who drives the refrigerant through the system, providing cooling. If compressor it buzzes, but does not start, or is silent at all, defrosting is inevitable. Often the problem lies not in the motor itself, but in the start-up relay, which protects the windings from overloads.
When the relay fails, it cannot supply the necessary impulse to start the engine. You may hear a characteristic click, followed by a hum, and then a click again - the engine is trying to start, but cannot. In this situation, the refrigerator defrosts completely because the cooling cycle does not begin.
⚠️ Attention: If you hear a loud clicking and humming noise, followed by silence, immediately unplug the appliance. Continuing attempts to start may lead to burnout of the compressor windings, which will require replacement of the entire unit.
Modern inverter models, such as Samsung or LG, use an inverter control unit instead of a conventional relay. Its diagnosis is more complicated and requires checking the output voltage. If the inverter is faulty, the compressor will not receive the required rotation speed and will not start.
It is also worth paying attention to the condition of the motor windings. If the compressor overheats greatly (its temperature exceeds 90 degrees), an interturn short circuit may have occurred. In this case, independent repair is impossible; replacement of the motor and vacuum pumping of the system are required.
Freon leakage and clogged capillary tube
Refrigerant (freon) is the working fluid that transfers heat from the chamber to the outside. If a microcrack has formed in the circuit, the gas gradually evaporates. The pressure in the system drops and freon ceases to effectively cool the evaporator. As a result, the refrigerator works almost non-stop, but does not produce cold, and the food begins to deteriorate.
Another common problem is a clogged capillary tube. Oil oxidation products or moisture may accumulate in the circulation system, which turns into an ice plug. This blocks the flow of refrigerant. The compressor tries to push gas, hums, but there is no circulation, and defrosting becomes a fact.
It is difficult to visually diagnose a leak, since freon is colorless and odorless. However, indirect signs can be:
- 🔥 Strong heating of the condenser grille at the rear only in the upper or lower part.
- 💧 The appearance of oily spots near the compressor or in places where the tubes are soldered.
- 🔇 The compressor works almost non-stop, trying to dial up temperature.
- ❄️ The evaporator in the freezer is covered with frost unevenly or does not cool at all.
To eliminate the leak, you need to find the location of the damage, solder it, replace the filter drier and fill the system with new gas. This is a job for a master with professional equipment. Trying to find a leak or solder pipes on your own without skills and tools is dangerous and ineffective.
Is it possible to refill a refrigerator yourself?
Theoretically, it is possible if you have a cylinder with freon and a manifold station. However, without evacuation of the system (removing moisture and air), the new freon will mix with the remnants of the old gas and air, which will lead to rapid breakdown of the compressor due to the formation of an acidic environment.
Failure of the No Frost system
Owners of refrigerators with the system No Frost often face a situation when the unit defrosts due to defrost cycle failure. In such models, the evaporator is hidden behind a plastic panel, and the frost that freezes on it is periodically removed by a heating element (heating element). If this mechanism breaks, ice blocks the air channels.
Cold air simply cannot enter the chamber, although the compressor is working properly. The freezer may be cold, but the refrigerator compartment may be warm. The main culprits of the failure:
- 💡 Burnout of the defrost heating element.
- 🕰️ Malfunction of the defrost timer or control module.
- 🌡️ Failure of the defrost sensor (defroster).
- 🚫 The drain hole is clogged, causing the water to not drain and freeze.
To check the system, it is often necessary to completely defrost the refrigerator within 24 hours. If after this the unit begins to freeze normally for a couple of days, and then stops again, then the problem is in the defrost cycle. Ice builds up again and blocks the channels.
In models Indesit and Ariston there is often a malfunction of the defrost sensor. It should open the heater circuit when the ice melts. If it is “stuck,” the heating element may heat up constantly (which is rare, but it happens) or not turn on at all. The sensor is checked by a continuity tester: at room temperature it should ring, and when heated it should open (or vice versa, depending on the type).
The influence of external factors and improper operation
The reason does not always lie in a breakdown. Sometimes the refrigerator defrosts due to user errors or external conditions. For example, if the unit is installed too close to a wall or heating appliances, air circulation around the condenser is disrupted. Heat transfer deteriorates and operating efficiency drops.
Another common reason is a door that is not tightly closed. If the sealing rubber is worn out, dirty, or the door is prevented from closing by a plate, warm air constantly flows inside. The compressor does not have time to compensate for heat loss, and the temperature rises. You can check the tightness using a sheet of paper: clamp it with the door and try to pull it out. If the sheet comes out easily without resistance, the seal requires replacement or cleaning.
⚠️ Attention: Installing the refrigerator in a niche without gaps or in a room with a temperature below +10°C (for example, on an unheated balcony) can lead to improper operation of the oil in the compressor and thickening of the lubricant, which will cause the unit to stop.
It is also worth checking the operating mode. If you have just loaded a large amount of warm food into the chamber, the refrigerator may work at high speed for a long time. During this period, it seems that it “does not freeze”, but in fact it simply cannot cope with the heat load. Give it time.
☑️ Checking the operating conditions
Diagnostics and table of symptoms
To understand why your refrigerator is defrosting, you need to carefully analyze the symptoms. Different breakdowns manifest themselves in different ways. Below is a table that will help narrow down your search.
| Symptom | Probable cause | Difficulty of repair | Necessary actions |
|---|---|---|---|
| The compressor is silent, there is no light no | No power, socket burned out, wiring faulty | Low | Check socket, cord, plug |
| Buzzing, clicking, won’t start | Faulty starting relay or compressor wedge | Medium | Replace the relay, check the windings |
| Works constantly, no cold | Freon leak or clogged capillary tubes | High | Call a technician to find a leak and refill |
| It freezes, but weakly, the cycles are short | The thermostat or sensor is faulty | Average | Replacing the thermostat |
| There is ice in the freezer, heat in the refrigerator | Clogged channels No Frost, defrost failure | Average | Thaw for a day, check the heating element and sensors |
When diagnosing, it is important to follow the sequence. Start with simple things: power supply, temperature settings, condenser cleanliness. If external causes are excluded, proceed to checking the internal components. Remember that the most common cause of complete defrosting while the compressor is running is a freon leak..
If you are not confident in your abilities, it is better not to risk it. Improper disassembly may damage the plastic parts or electrical parts. In models with electronics, such as Bosch or Siemens, an error in connecting sensors can damage an expensive control module.
Frequently asked questions (FAQ)
Why did the refrigerator defrost after the lights were turned off?
If the lights were turned off for a short time, food could begin to melt due to the fact that the door was opened to check the contents. Warm air speeds up defrosting. If there was no electricity for several hours, then this is a natural process. After turning on, give the refrigerator 2-3 hours to set the temperature without loading it with food.
Is it possible to use a defrosted refrigerator?
For a short time - yes, if the food is still cold. But you cannot operate equipment that does not maintain temperature. This will lead to food spoilage and increased load on the compressor, which will work hard trying to compensate for heat loss. This can permanently damage the motor.
How long does it take to defrost a refrigerator without electricity?
The time depends on the load and the ambient temperature. Complete defrosting takes from 4 to 24 hours. In No Frost models with good insulation, food can remain cold for up to 8-10 hours if the door is not opened. In older models with a crying evaporator, this process goes faster.
What to do if it is warm in the refrigerator and cold in the freezer?
This is a classic sign of problems with air circulation (in No Frost) or partial leakage of freon. Check if the air supply channel between the chambers is frozen. The fan that circulates cold air could also fail. In two-compressor models, one of the motors could fail.
How often do you need to defrost the refrigerator manually?
Models with a system No Frost there is no need to defrost, it is enough to wash it once every six months or a year. Old models with a “crying” wall require manual defrosting as an ice coat 5-7 mm thick forms, usually 1-2 times a year. Ignoring defrosting leads to increased energy consumption.