Many owners of modern refrigeration units, looking inside the freezer, you notice a small plastic element resembling a tube or stick. This item often goes unnoticed, and sometimes even causes confusion: what is it there for and is it a defect?
In fact, this plastic tube plays an important role in the operation of the No Frost system. It connects the internal temperature sensor to the evaporator, which is hidden behind the back wall of the chamber. Without this element, correct operation of the automation would be impossible, since the sensor must read real cold indicators, and not the air temperature inside the freezer.
In this article we will look in detail at how exactly this system works, why it is important not to damage the tube and how it can be used to speed up defrosting. Understanding the principle of operation No Frost will help you extend the life of your household appliances.
The design and operating principle of the heat removal system
Refrigerators with the system No Frost are more complex than their counterparts with a drip defrosting system. In them, the evaporator, where the refrigerant is directly cooled, is hidden behind a plastic panel on the back wall of the freezer. Air circulates through special channels, cooling the products.
The plastic stick you see is part of capillary tube. Inside it there is a special liquid or gas that reacts to changes in temperature. One end of this tube is fixed to the evaporator itself (behind the wall), and the second, visible to you, is freely accessible or fixed to the inner surface.
The end of the tube in the freezer is connected to a thermostat or electronic sensor. When the temperature at the evaporator drops to the set value, the sensor sends a signal to the compressor to turn off. If the sensor were just hanging in the air of the freezer, it would react with a delay, and the food could freeze.
⚠️ Attention: Never try to tear off or bend this tube with force. It may be filled with refrigerant or sensitive liquid inside. Damage to the seal will lead to failure of the entire thermoregulation system.
Thus, the visible part is only the “tail” of a complex heat exchange system. It ensures accurate readings, which is critical for maintaining food freshness and saving energy.
Using a stick for faster defrosting
One of the most useful functions of this element is the ability to quickly defrost the refrigerator. Although the No Frost system assumes automatic removal of moisture, once every year and a half it is recommended to carry out a complete defrost for hygienic treatment and removal of ice, which can still accumulate in hard-to-reach places.
There is a proven life hack that uses this very tube. If you need to quickly defrost the freezer, you can insert a plastic stick into the cavity (if it is hollow and open at the top) or press a heating pad with warm water tightly to its end. Heat through the walls of the tube will quickly be transferred to the hidden evaporator.
This allows you to melt the ice on the evaporator much faster than if you simply leave the door open. The ice begins to melt evenly over the entire area of the heat exchanger, and not just from the surface.
- 🌡️ Heat is transferred directly to the cold source, bypassing the air gap.
- ⏱️ Defrosting time is reduced by 2-3 times compared to natural thawing.
- 💧 Water flows into the standard drainage without spilling along the bottom of the chamber.
However, you should be careful. The water in the heating pad should not be boiling water, so as not to melt the plastic itself or create a sharp temperature difference that is dangerous for the metal of the evaporator. The optimal temperature is 40-50 degrees Celsius.
Diagnostics of faults through a capillary
The visible part of the capillary tube can serve as an indicator of the state of the system. Experienced professionals sometimes use it for initial diagnosis. If the refrigerator has stopped freezing, but the compressor is working, the state of this zone may indicate the reason.
For example, if the tube is covered with frost along its entire length right up to the exit from the wall, this may indicate lack of refrigerant or problems with circulation. In normal mode, only the hidden evaporator should freeze, and not the external elements.
You can also sometimes try to clean the drain hole through this channel if it is clogged with ice or debris. To do this, use a thin soft wire or a special brush, carefully inserting it into the hole where the tube goes (if the design allows it).
| Symptom | Possible cause | Action |
|---|---|---|
| The tube is frozen outside | Tightness failure or lack of freon | Call a technician to check the circuit |
| The tube is warm when the compressor is running | Faulty compressor or thermostat | Check electrical circuit |
| Water inside the tube | Moisture got in during washing or defrosting | Blow with air, dry |
| Crack in the plastic | Mechanical damage | Replacing the sensor or repairing the case |
Diagnostics through external signs is only the first step. If you notice strange behavior of the tube, it is better to contact a specialist.
⚠️ Attention: If you find that oil is oozing from or around the tube or you can hear gas hissing, immediately unplug the refrigerator and ensure the room is ventilated. This is a sign of depressurization of the freon circuit.
Features of care and cleaning of the sensor area
The area around the plastic tube is often clogged with crumbs, ice or mold, as condensation accumulates there. Regular cleaning of this area is necessary to maintain hygiene and correct operation of the sensor.
For cleaning, use a soft cloth soaked in a weak soda solution or a special household appliance cleaner. Do not use abrasive pads, which may scratch the plastic. Scratches will become a place for bacteria to accumulate.
If ice has accumulated in the hole in the tube, it must be carefully removed. You can use a hairdryer in cold air mode or just wait for it to thaw. Picking the ice with a knife It is strictly prohibited - there is a high risk of breaking through the evaporator wall.
☑️ Caring for the freezer
After cleaning, make sure that the sensor (if it is brought out in the form of a “fungus” at the end of the tube) fits tightly into place. If it hangs, the temperature readings will be incorrect and the refrigerator will work under overload.
Why you can’t ignore tube damage
Some users, having noticed a crack in a plastic tube, consider it a cosmetic defect. This is a dangerous misconception. As mentioned earlier, the working fluid of the thermoregulation system can circulate inside.
If the integrity is broken, the gas or liquid evaporates. The thermostat stops receiving signals about the evaporator temperature. As a result, the compressor may work continuously, trying to catch up with the cold, or, conversely, not turn on at all.
Consequences of ignoring the problem:
- ❄️ Freezing of food due to continuous operation of the compressor.
- 📉 Spoilage of food due to defrosting when turned off compressor.
- 💸 A sharp increase in electricity bills.
- 🔥 Compressor failure due to overheating.
If you notice damage, it is better to immediately order a replacement of the sensor or capillary tube at the service center. The cost of repairs at an early stage will be significantly lower than replacing a burnt-out motor-compressor.
Is it possible to seal a crack in a tube?
Self-sealing with ordinary glue or sealant is a temporary and risky measure. Most household adhesives do not withstand low temperatures and crack. In addition, you will not be able to restore the lost working fluid (gas/liquid) inside the system. Professional refueling and soldering are required.
Comparison of systems: where is such a stick found
You will not see this element in all refrigerators. Its availability depends on the type of defrosting system and unit model. Let's look at where exactly you should look for this part.
In older models with manual defrosting, the evaporator is located directly in the freezer compartment (often this is a ribbed panel). There are no hidden channels, and the sensor, if there is one, is attached directly to the wall or hangs in the air.
In modern models with Total No Frost or Frost Free such a tube is a standard design element. It can be made in the form of a thin white hose coming from the back wall, or be integrated into a plastic box.
Some premium models use wireless sensors or sensors built directly into the body without visible tubes, but this is rather the exception. Most mass-market refrigerators (Indesit, Samsung, LG, Bosch) use a classic design with a capillary.
⚠️ Attention: Characteristics and arrangement of elements may vary depending on the specific model and year of manufacture. Always check the manufacturer's instructions (manual) that come with your device before carrying out any manipulations.
Understanding what type of refrigerator is in your kitchen helps to properly care for it and quickly find the cause of malfunctions.
Frequently asked questions (FAQ)
Is it possible to cut off this stick if it interferes with placing pots?
Absolutely not. Cutting off the tube will break the seal of the thermoregulation system. The refrigerator will no longer detect the temperature correctly, which will lead to food spoilage and compressor failure. If the tube is in the way, try to redistribute the products or carefully (without force) change the angle of its inclination, if the design allows it.
Why does cold air blow from the tube?
In the No Frost system, cold air circulates through the channels. If the tube is part of an air duct (in some models it is hollow and serves to draw air to the sensor), then air movement through it is normal. However, if it blows strongly from there, check whether the dampers are knocked down.
How can you tell that the sensor inside the tube is faulty?
Main signs: the refrigerator “threshes” without stopping and makes a loud noise, or turns off for a long time and the food melts. The alarm indicator on the control panel may also light up. Only a master can carry out an accurate diagnosis using a multimeter.
Is it necessary to lubricate the tube with oil?
No, lubrication is not required and is even harmful. The sticky surface will attract dust and dirt, which will impair heat transfer and can lead to corrosion or damage to the plastic over time. The surface should remain dry and clean.
Can this tube be used to attach hooks?
Not recommended. Plastic may not support the weight, especially when frozen, it becomes brittle. In addition, pressure on the tube can be transferred to elements hidden inside. Use only standard fasteners on the walls of the refrigerator.