The situation when a refrigerator with a system No Frost suddenly stops freezing always takes you by surprise. Products begin to deteriorate, and condensation or ice crust appears on shelves where there should not be any. The owner of the unit is immediately faced with the question of why the equipment designed to get rid of ice itself became a victim of icing or, conversely, stopped cooling.
Unlike old drip models, where the reason often lay in clogged drainage, in systems No Frost the mechanics are more complicated. Here fans provide air circulation, and a whole complex of sensors and heaters is responsible for defrosting the evaporator. If one of the elements of this circuit fails refrigerator compartment or the freezer stops performing its function.
Before calling a technician or looking for a new unit, it is necessary to carry out an initial diagnosis. Often the problem lies in small things that you can fix yourself in a matter of minutes. However, there are also serious technical malfunctions that require the intervention of a professional s refrigeration equipment. Let's figure out what exactly could happen to your device.
Primary diagnosis and simple causes
The most commonplace, but often ignored reason is a violation of the chamber seal. If sealing rubber the door is worn out, torn or simply dirty, warm air constantly enters the chamber. The compressor tries to compensate for the heat, working without interruption, but in the end the system No Frost cannot cope with the volume of moisture, and the temperature inside rises.
It is also worth checking the temperature settings. An accidental electronic failure or childish pranks could change the parameters. For most models, the optimal temperature in the main chamber is considered to be from +3 to +5 degrees, and in the freezer - about -18 degrees. If you see the value -6°C in the freezer, this is clearly not normal.
⚠️ Attention: If the compressor runs continuously for more than 24 hours and the temperature does not drop, this is a sure sign of either a refrigerant leak or a serious malfunction of the defrost system. Do not leave the equipment in this mode for a long time so that the motor does not burn out.
Another important factor is the location of the products. In systems No Frost cold air circulates forcibly through special channels. If the shelves are packed to capacity, or the products lie close to the back wall, blocking the air duct openings, the cold simply does not enter the main part of the chamber.
Malfunctions of the defrost system (Defrost system)
The heart of the system No Frost is the automatic defrosting mechanism. Unlike the drip system, the evaporator is hidden behind a back panel in the freezer. Frost grows on it, which should periodically burn out thanks to Defrost heating element. If this process is disrupted, the ice block blocks the fan, and the cold stops flowing into the chambers.
The key element here is defrost timer or the electronic control module. It is he who gives the command to turn on the heater. If the timer is stuck in cooling mode, the heating element will never turn on, and the evaporator will become covered with ice. In modern models, this is responsible for electronic controller, which is more difficult to diagnose without a special tester.
- 🔥 TEN defrost - heating element that can burn out and stop heating.
- 🌡️ Defrost thermostat —a sensor that turns off heating when a certain temperature is reached can “lie.”
- ⏱️ Timer —a mechanical or electronic switch for the operating modes of the compressor and heating element.
Diagnostics of these elements requires partial disassembly of the freezer. It is necessary to remove the back plastic panel, get to the evaporator and check the integrity of the heater circuit with a multimeter. The resistance of a working heating element is usually several hundred Ohms. If the device shows a break (infinity), the part must be replaced.
How to understand that the problem is in the defrost system?
If you removed the back panel in the freezer and saw that the evaporator is completely covered with ice or snow, and the fan does not spin or hums, stuck in the ice, the problem is 100% in the defrost system. The compressor may work properly, but the cold simply does not pass through the ice plug.
Problems with air circulation and fan
The main difference No Frost from other systems is the presence of a fan (fan motor). It drives cold air from the evaporator throughout all chambers of the refrigerator. If the fan stops, the freezer may be cold, but the temperature in the upper compartment will quickly rise to room temperature.
The reasons for the fan stopping may vary. The most common is freezing of the blades due to a malfunction of the defrost system, which was mentioned above. Ice blocks rotation, the motor hums, but does not spin. The second reason is the failure of the fan motor itself. The third is a break in the wiring going to it.
To check the operation of the unit, you need to open the freezer door. In many models, when the door is open, the fan should stop (the limit switch is activated), but if you press the limit switch artificially, it should start working. If you hear a hum, but there is no rotation, you need to lubricate the bushings or replace the motor.
⚠️ Attention: Do not try to rotate a jammed fan by force. This can lead to bushings breaking or motor windings burning out. First, make sure that there is no ice on the blades.
Freon leakage and compressor malfunction
If the defrost system and fan are working properly, but the refrigerator still does not freeze, the problem may be in the “circulatory system” of the unit. Refrigerant (freon) circulates through the tubes, taking away the heat. If a microcrack has formed in the circuit, the gas gradually evaporates. First, the refrigerator begins to freeze worse, then it stops completely, and the compressor works non-stop.
A freon leak is not a case where you can do it yourself. It requires searching for the leak, sealing, evacuating the system and refilling with new gas. Independent attempts to “fix” the refrigerator often lead to the final failure of the compressor, since along with freon, compressor oil also leaves the system. Failure of the compressor itself is also possible. The engine may hum, click, but not start, or start and immediately stall. This often happens due to interturn short circuit of the windings or jamming of the piston group. In this case, an expensive replacement of the unit is required. compressor oil.
It is also possible that the compressor itself may fail. The engine may hum, click, but not start, or start and immediately stall. This often happens due to interturn short circuit of the windings or jamming of the piston group. In this case, an expensive replacement of the unit is required.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor is silent, there is no light | No power, burnt out relay | Low |
| Buzzes, but does not freeze | Freon leak, capillary clogged | High (needs a technician) |
| Freezes only near walls | System malfunction No Frost | Medium |
| Clicks and turns off | Faulty compressor or start relay | High |
Electronics and temperature sensors
Modern refrigerators No Frost are stuffed with electronics. They are responsible for the temperature sensors (thermistors). There may be several of them: in the refrigerator, in the freezer, on the evaporator. If the sensor “lies” and shows that the chamber is already -20 degrees, although it is +10, the control module will turn off the compressor.
Sensors are checked by measuring their resistance at different temperatures. Typically, at room temperature the resistance is several kiloohms, and when cooled it increases. The resistance table for a specific model can be found in the service manual. Replacing the sensor is a simple procedure, but it requires precision.
In some cases, the culprit itself becomes control module. Power surges in the network can damage board elements. Symptoms can be chaotic: the refrigerator sometimes freezes, sometimes it doesn’t, indicators flash, settings get lost. Board repair requires soldering skills and knowledge of circuit design.
☑️ Electronics diagnostics
When defrosting is necessary and how to do it correctly
Even the system No Frost sometimes requires manual defrosting. If you haven't cleaned your refrigerator for a long time, or there was a power surge that interrupted the timer, ice could accumulate in hidden cavities. Complete defrosting is the first thing you need to do before calling a technician.
For proper defrosting, you need to completely unplug the refrigerator, remove all food and leave the doors open for at least 24 hours. A shorter time (for example, 2-3 hours) is often not enough to melt the ice deep in the air ducts and on the evaporator, where warm air from the room does not enter.
After defrosting, turn on the unit empty. If after a couple of hours it gains temperature and freezes normally, the problem was an ice jam. If the situation repeats after a week or two, it means that one of the elements of the defrosting system (heating element, timer, sensor) is faulty and needs to be changed.
⚠️ Attention: Never use a hairdryer, hot water or a knife to chip ice inside the chambers. A hairdryer can melt the plastic, and a knife can damage the evaporator tubes, which will lead to an immediate release of freon and expensive repairs.
FAQ: Frequently Asked Questions
Why does the No Frost refrigerator freeze only near the back wall?
This is a classic sign of a malfunction of the air circulation system. Most likely, the evaporator in the freezer is frozen, and the fan cannot drive the cold through the air ducts. Or the air supply channel is clogged. Defrosting and diagnostics of the defrosting heating element are required.
Is it possible to operate the refrigerator if it has stopped freezing?
For a short time - yes, if you are waiting for a technician. But if the compressor runs continuously, it can burn out due to overheating. It is better to turn off the device, defrost it and carry out diagnostics. You cannot store food in a warm place.
How much does it cost to replace a defrost heating element?
The cost consists of the price of the spare part (usually from 500 to 2000 rubles, depending on the model) and the cost of the technician’s work. Replacing it yourself is cheaper, but requires disassembly skills and working with a multimeter.
Why, after defrosting, did the refrigerator stop freezing again after a week?
This means that the reason has not been eliminated. Defrosting removed the effect (ice), but not the cause (faulty sensor, timer or heating element). The system will again accumulate ice and block operation. The defrost unit needs repair.