Sudden An increase in temperature in the refrigerator compartment and the appearance of puddles on the floor is always stressful for the owner, because fresh food supplies are at risk. If your refrigerator periodically defrosts, this indicates a failure in one of the unit’s systems, be it the defrost system, circuit tightness, or compressor operation. Ignoring the first signs can lead to complete breakdown of expensive equipment and damage to all contents.
In this article we will analyze in detail the mechanics of the process: why equipment designed to store cold suddenly begins to behave like a heat gun. We will consider both simple operating errors that can be corrected in five minutes, and complex technical malfunctions that require the intervention of a technician. Understanding the principles of operation of your model will help save time and money. diagnostic equipment. Understanding how your model works can save you time and money.
Modern systems No Frost and drip refrigerators have different defrosting algorithms, but the essence of the problem often lies in similar elements. The critical factor is the downtime of the compressor: if it does not turn on for more than 4-6 hours, the temperature in the chamber is guaranteed to rise to room temperature. Let's figure out what exactly interrupts the cycle cooling.
Failures in the automatic defrosting system
The most common reason why the refrigerator periodically defrosts is the failure of defrosting system components evaporator. In units with technology No Frost ice on the heat exchanger should be regularly melted by the heating element, and water should drain into the drain pan. If this process is disrupted, the ice blocks air circulation and the cold stops flowing into the chamber.
The main suspect here is Defrost heating element. This is a nichrome spiral, which must heat up at the command of a timer or electronic module. When the coil burns out, the ice does not melt, a “fur coat” grows, and the fan stops moving air. As a result, the compressor works non-stop, trying to cool the chamber, but to no avail, until the thermal protection relay is triggered.
The second important element is defrost sensor (thermostat). It monitors the temperature of the evaporator and tells the control unit when to turn off the heating. If the sensor is “stuck” in the “heating off” position, the heating element will not start even at the timer command. In older models, the mechanical timer itself also often breaks down, which simply stops switching contacts.
⚠️ Attention: When checking the heating element with a multimeter, be sure to turn off the power to the refrigerator. The resistance of a working spiral is usually from 200 to 400 Ohms, depending on the power of the model.
For diagnostics, you will need to remove the back panel in the freezer and visually assess the condition of the evaporator. If it is covered with a thick layer of ice, and the heating element is cold when the defrost mode is on, there is a problem in the heating circuit.
- 🔥 The defrosting heating element: it burns out due to nichrome aging or corrosion.
- 🌡️ Temperature sensor: gives incorrect readings or breaks.
- ⏱️ Timer/Module: does not give a signal to start the defrosting cycle.
Don't forget about the drainage system. If the water drainage tube is clogged with debris or frozen at the bottom, the melt water does not drain away, but freezes at the bottom of the evaporator, forming an ice plug. Over time, this lump of ice blocks the air supply channels, and the refrigerator stops cooling, starting a cycle of defrosting the products inside the chambers.
Problems with the refrigerant and compressor
If the defrosting system is working properly, but the cold still disappears, it is worth checking the “heart” of the refrigerator - the compressor and the freon circulation circuit. Refrigerant leak is an insidious problem that can manifest itself precisely through periodic defrosting. The gas slowly escapes through microcracks, and its quantity is only enough for short-term cooling.
Symptoms of a leak often look like this: the refrigerator hums, works almost non-stop, but the temperature inside is rising. At some point, the compressor may shut down due to overheating or an electronic command, and rapid defrosting of the contents will begin. You can check this by touching the condenser grille from behind: it should be warm evenly.
The other extreme is compressor malfunction. The motor may start, hum for a few minutes, and then click and shut off. This indicates an interturn short circuit of the windings or jamming of the mechanism. In such cases, the equipment turns on rarely and for a short time, which physically does not allow maintaining a low temperature.
It is also worth mentioning a clogged capillary tube. If a plug of moisture or oil breakdown products forms in the circulation system, freon cannot circulate normally. The pressure at the compressor outlet increases, but there is no cold in the evaporator. Periodically, this plug may “release” and the refrigerator will start working, but soon the cycle will repeat.
| Symptom | Probable cause | The nature of the compressor |
|---|---|---|
| It hums, but does not get cold | Freon leak | Works without stopping |
| Clicks and turns off | Motor malfunction | Short cycles (5-10 min) |
| Hot condenser | System clogged | Operates with overload |
| Cools poorly | Lack of freon | Long operation |
Faults in electronics and sensors
Modern refrigerators such as Liebherr, Bosch or LG, are controlled by complex electronic modules. If the “brain” of the equipment malfunctions, it can send incorrect commands to the actuators. For example, the control module may “think” that the required temperature has already been reached in the chamber and does not turn on the compressor for hours.
Often the culprit is temperature sensor in the chamber itself. If it has moved out of place, stuck to the wall, or is simply lying, the readings on the board will be distorted. The electronics will receive a “too cold” signal and turn off the refrigeration, causing the food to defrost. Replacing such a sensor is a quick and inexpensive procedure.
In models with inverter compressor the inverter board itself can create problems. It regulates the rotation speed of the motor, and in the event of power surges or an internal defect, it can block starting. In this case, the refrigerator may not respond at all to attempts to turn on or operate in emergency mode.
⚠️ Attention: Electronic modules are sensitive to power surges. Using a network stabilizer can extend the life of the control board and prevent false alarms.
Diagnostics of electronics requires special knowledge and often connection to the service connector to read error codes. However, you can visually check the board for the presence of swollen capacitors or traces of burning.
- 🔌 Control module: burnt tracks or relays.
- 📉 NTC sensors: resistance change outside the norm.
- 🔋 Indication block: failures in transmitting commands from buttons.
How to reset an electronics error?
In many models, to reset an error, you need to press and hold a certain combination of buttons (for example, “Defrost” and “Temperature”) for 10-15 seconds, or briefly disconnect the power from the network. Look for the exact combination in the instructions for your model.
The influence of seals and chamber tightness
It would seem that what an elastic band on the door can do? But it is precisely seal that ensures the tightness of the internal volume. If it is torn, dried out or simply dirty, warm, moist air from the kitchen constantly enters the chamber. The refrigerator does not have time to cool it, the moisture condenses and freezes, and the food begins to deteriorate.
You can check the tightness with a simple test with a sheet of paper. Clamp the sheet with the door around the entire perimeter. If the paper is pulled out easily, without resistance, it means that the seal does not fit in this place. Problems especially often arise in the corners of the door or in the hinge area.
It is also worth checking whether the door itself is warped. If the refrigerator is not level or the hinges are loose, the door may not close completely. In models with Total No Frost loose fit leads to rapid fouling of the evaporator with ice, which again brings us back to problems with air circulation.
Regular washing of the seal with warm water and soap helps maintain its elasticity. Once every six months, it is recommended to lubricate the rubber with silicone grease to prevent drying out and cracking of the material.
☑️ Checking the seal
Operation errors and external factors
The reason is not always a breakdown. Sometimes the refrigerator becomes defrosted due to improper handling. For example, loading hot food into the chamber sharply increases the temperature and humidity inside. The cooling system wears out, and sensors may not read data correctly, which leads to failures in the work cycle.
The location of the equipment also plays a role. If the refrigerator is placed close to a wall or in a niche without gaps for ventilation, the condenser overheats. Heat transfer efficiency drops, the compressor runs longer, and at some point the protection system turns off the unit to prevent a fire. After cooling, it will turn on again, but the cycle will be disrupted.
Frequent and prolonged opening of doors, especially in hot weather, also contributes to temperature disturbances. Humid air quickly saturates the chamber, and even a working refrigerator may not be able to remove excess heat and moisture, which leads to the formation of ice and a temporary increase in temperature.
⚠️ Attention: Do not install the refrigerator near heat sources (radiators, ovens) or in direct sunlight. This creates a critical load on the cooling system.
In addition, using the “Super Freeze” mode for longer than necessary (more than 24-48 hours) can lead to the fact that the refrigerator will not go into normal mode, but will operate at maximum capacity, which will ultimately cause a failure or defrost due to overheating of the components.
Algorithm self-diagnosis
Before calling a technician, try to carry out the initial diagnosis yourself. This will help you more accurately describe the problem to a specialist or, perhaps, resolve the issue yourself. Start with a visual inspection and listening to the operation of the unit.
First of all, defrost the refrigerator completely (for at least 12 hours, preferably for a day). This is necessary to eliminate the influence of ice jam. If after switching on the cold appears and remains stable for several days, the problem was in the defrost system or a blockage. If the cold disappears quickly again, look for a leak or a compressor malfunction.
Pay attention to sounds. Loud humming, gurgling, clicking, or complete silence from the compressor are all important diagnostic signs. Also check if the light inside is on when the door is closed (sometimes the door sensor gets stuck and the light stays on constantly, heating the chamber).
If you find that the compressor is hot, but does not start, or you hear a burning smell - immediately unplug the device. Further operation may lead to a fire or complete failure of the motor.
FAQ: Frequently Asked Questions
Why does the refrigerator defrost at night when it is not opened?
This may be due to the scheduled defrost cycle, which in some models is set for night time, or to surges voltage in the network that interferes with the operation of the electronic module. It is also possible that during the day the load on the network is high, and the compressor cannot start, and at night it tries to compensate for the heat.
How long do food remain safe when defrosted?
In a closed chamber of a full refrigerator, food remains cold for up to 4-6 hours. In a fully loaded freezer, this period can reach 12-24 hours. If the temperature inside has risen above +4°C for more than 2 hours, it is better to dispose of meat and dairy products.
Is it possible to use a refrigerator if it is periodically defrosted?
For a short time - yes, if you control the temperature of the products. However, constant temperature changes are harmful to the compressor (water hammer when starting) and lead to food spoilage. Operating in this mode is a temporary solution until repair.
Why does the refrigerator take a long time to get cold after defrosting?
If you defrosted it for less than 12 hours, water or ice could remain inside in hidden cavities. It is also possible that air remains in the system (if there was a leak) or oil has entered the circuit. Normally, cold should appear after 1-2 hours of operation.