Owners of refrigeration equipment are often faced with a situation where heavy ice forms inside the chamber, interfering with normal operation. If you notice that rear wall your unit is covered with a thick layer of frost or ice, this indicates a violation of the defrosting cycles. In refrigerators Pozis, as in other equipment with a system No Frost or drip defrosting, such a failure requires immediate intervention.
Ignoring the problem can lead to failure of the compressor or damage to door seals due to inflating the chamber with ice. It is important to understand that freezing is not just a cosmetic defect, but a symptom of a malfunction defrost systems or a violation of the tightness of the circuit. Let's look at the main technical reasons why this happens and methods for eliminating them.
⚠️ Attention: Before starting any diagnostic or repair work, be sure to disconnect the refrigerator from the power supply. Working with electrical appliances under voltage is dangerous to life.
The principle of operation of the defrost system in Pozis refrigerators
To understand the causes of icing, it is necessary to briefly consider the operating algorithm of the unit. In models Pozis with the system No Frost the evaporator is hidden behind the rear panel of the freezer. The fan circulates cold air, and periodic switching on Defrost heating element melts the ice on the evaporator. The water flows into the drainage tray and evaporates.
If this cycle is disrupted, the water stops being removed and freezes, turning into a block of ice. This process is controlled by an electronic module or mechanical timer, which receives signals from temperature sensors. A failure in the control circuit leads to the fact that the refrigerator begins to freeze continuously, ignoring the need to defrost.
In drip models (“Crying Wall”), the principle is different: moisture condenses on the back wall of the refrigerator compartment and flows down. If the wall has turned into an ice monolith, it means that the heat exchange is disrupted or the thermostat does not turn off the compressor in time. Temperature conditions in such cases it goes astray, the products can freeze.
Failures of sensors and thermostats
One of the most common reasons why the back wall freezes is failure defrost sensor. This small element controls the temperature of the evaporator. If it “lies” and shows that the evaporator is warm, the control module does not turn on the heater. As a result, the ice does not melt and grows with each cycle.
Also, the culprit may be itself thermostat (thermostat). Old models Pozis have mechanical thermostats, the contacts of which stick over time. The compressor works non-stop, freezing out all the moisture from the chamber. In modern models, an electronic sensor is responsible for this, which also requires checking the resistance with a multi-meter meter.
- ❄️ Defrost sensor: usually located on the evaporator tube, at temperatures below 0-10 degrees it should open the circuit or change the resistance.
- 🌡️ Thermostat: regulates the duration of operation of the compressor; if it breaks down, the refrigerator hums continuously.
- 💻 Control module: less often, but it happens that the “brains” of the refrigerator stop sending a signal to defrost.
Diagnostics of these elements requires skills in working with with a multimeter. It is necessary to “ring” the sensors in cold and heated states. If the readings do not change or the circuit is broken, the part must be replaced. It is important to use original spare parts or high-quality analogues, since the response parameters may differ for different models.
Problems with the heater (heating element) of the evaporator
If the sensors are working, but ice continues to accumulate, it is worth checking Defrosting heating element. This is a nichrome coil enclosed in a metal tube that directly heats the evaporator. Over time, the spiral may burn out, especially if there have been power surges in the system.
Checking the heating element is carried out by visual inspection and ringing. Visually, there should be no swelling, black spots or breaks on the tube. When measuring resistance, a working heating element should show a value within the normal range (usually from 200 to 800 Ohms, depending on the power). If the device shows “infinity” (break), the heater has burned out.
⚠️ Attention: Replacing the heating element requires complete defrosting of the refrigerator within 24 hours. Trying to remove the back panel with ice can lead to damage to plastic parts or tubes.
Sometimes the cause is not the heater itself, but the oxidation of the contacts at the place where it is connected. In conditions of high humidity inside the chamber, the wires can oxidize, and the current simply does not reach the heating element. In this case, it is enough to clean the contacts or replace the terminals. However, if the heating element itself burns out, the only help is replacing the unit.
How to check the heating element correctly?
To check, disconnect the wires from the heater. Switch the multimeter to resistance (ohms) measurement mode. Touch the leads of the heating element with the probes. If there are numbers on the screen (for example, 350 Ohms), the heating element is intact. If one or zero, the heating element is faulty.
Clogged drainage system
Even if the defrosting system works perfectly, the water must go somewhere. For this purpose, there is drainage holelocated at the bottom of the rear wall (in the refrigerator) or under the evaporator (in the freezer). If this hole becomes clogged with crumbs, mold or ice, the water has nowhere to go.
Water accumulates in the pan, freezes and gradually rises up, forming ice on the back wall and bottom of the chamber. This is a common problem that can be easily overlooked. In the freezer, the drainage often freezes from the inside, forming an ice plug in the tube.
☑️ Cleaning the drainage
For cleaning, you can use a soft wire twisted into a bundle, or a medical syringe with warm water. Do not use sharp metal objects to avoid piercing the channel and damaging the insulation. After cleaning, it is recommended to pour a little warm water into the hole to make sure that it flows freely into the tray above the compressor.
Tightness failure and problems with the seal
Foreign air is the main enemy of the refrigerator. If sealing rubber band the door is worn out, dirty or deformed, warm, moist air from the room constantly enters the chamber. The humidity rises sharply, and the defrosting system simply does not have time to remove all the water.
You can check the tightness in a simple way: clamp a sheet of paper between the door and the body in different places around the perimeter. If the paper pulls out too easily or falls out, there is no seal in that area. It is also worth inspecting the rubber itself for cracks and adhering dirt.
In addition, the cause may be a misalignment of the door due to loose hinges. If the door is skewed, it will not fit tightly even with the seal intact. In this case, it is necessary to adjust the hinges or replace seal. Constant operation of the compressor in an attempt to cool the incoming warm air also contributes to increased freezing.
Fault diagnosis table
For convenience, we systematize the main symptoms and probable causes in a table. This will help you quickly figure out which node requires attention first.
| Symptom | Probable cause | Check method | Difficulty of repair |
|---|---|---|---|
| Ice only on the evaporator (behind the panel) | The heating element or defrost sensor is faulty | Ringing with a multimeter | Average |
| Ice on the back wall of the refrigerator compartment | Thermostat is stuck or the drain is clogged | Visual inspection, drain check | Low |
| The refrigerator hums without turning off | The circuit is leaking or freon is leaking | Checking the door fit, inspecting the pipes | High |
| Water on the floor under the refrigerator | Clogged drainage channel | Blowing or flushing with water | Low |
Rare causes: freon leakage and errors electronics
Sometimes the problem lies deeper. If refrigerant circulation occurs in the system freon leak, the compressor will work continuously, trying to gain temperature. In this case, the evaporator may become covered with uneven ice (“fur coat”), and the rear wall with an ice crust. This requires calling a technician to find the leak and refill it.
In models with electronic control, the board itself may fail. Power surges in the network could damage the triac that controls the heating element. In this case, the board may visually look intact, but it will stop giving commands to defrost. Electronics diagnostics are complex and require special knowledge.
The human factor is also worth mentioning. If you put a hot pan in the refrigerator or left the door open for a long time, the system could go into emergency mode or simply not cope with the volume of moisture. In this case, complete defrosting within 24 hours is sufficient.
⚠️ Attention: Technical characteristics and location of components in Pozis refrigerators may vary depending on the year of manufacture and model. Always check the technical documentation of the specific device.
Prevention and proper care
To avoid the reappearance of ice, it is important to follow the operating rules. Do not load food into the chamber that is warmer than room temperature. Keep the drainage hole clean and regularly (once every six months) check the integrity of the seal.
Do not fill the refrigerator with food to capacity. Air circulation must be free. If you notice the first signs of icing, do not wait until the ice turns into a block. Timely defrosting and checking the water drainage will extend the life of your Pozis for many years.
Regular washing of the internal surfaces and ventilating the chamber also helps maintain an optimal level of humidity. Remember that a working refrigerator operates silently (as much as possible) and does not require frequent manual defrosting.
Why does ice appear only after defrosting after a short time?
Rather In total, the main defect was not eliminated. Either there is a blockage in the drain, or the defrost sensor is faulty. It is also possible that the refrigerator did not have time to dry completely before turning it on, and the residual moisture quickly froze.
Can you use a hair dryer to speed up the defrosting of ice?
You can use a hair dryer, but with great caution. Do not direct the hot jet at one point of the plastic for a long time, it may become deformed. It is strictly forbidden to chip off the ice with a knife or screwdriver - there is a high risk of puncturing the evaporator, after which repairs will be economically unfeasible.
How often do you need to defrost the Pozis No Frost refrigerator?
The No Frost system involves automatic defrosting. However, once every 6-12 months it is recommended to carry out a complete manual defrosting for hygiene, washing and checking the drainage system. This will help avoid the accumulation of bacteria and odor.
What to do if, after replacing the heating element, ice appears again?
It is necessary to check the entire circuit. Perhaps it is not the heating element that is faulty, but the sensor that does not give the command to turn it on. Or the problem is in the control module. Also check whether the back panel is tightly assembled - if there are cracks, cold air can bypass the chamber, disrupting circulation.