The situation when the refrigerator compartment becomes suddenly warm, food begins to deteriorate, and in the freezer the ice lies in a monolith, causes bewilderment and panic. This is a classic symptom that often misleads equipment owners, because it seems illogical that the same device functions halfway. In fact, in modern models, especially with the system No Frost, the refrigerator and freezer compartments have a common circulation of cold, but different temperature control points.
If the upper part has stopped cooling, this means that cold air does not physically reach the evaporator in the upper compartment or the sensors are transmitting incorrect signals to the control module. This problem cannot be ignored, since compressor it can run idle, trying to achieve the specified parameters, which leads to its overheating and expensive repairs.
In this article we will analyze in detail the mechanics of the process, consider typical malfunctions from a banal blockage to a refrigerant leak, and We will determine what actions you can take on your own, and when it is better to call a specialist. Understanding the operating principle of your model Indesit, Beko or LG will help save time and money.
The operating principle and distribution of cold in the chamber
To understand the nature of the breakdown, you need to understand the physics of the refrigeration unit. Most modern refrigerators use a single-circuit system, where the cold is generated in one place - the evaporator, which is usually hidden behind the back wall of the freezer. From there, cooled air is forced by a fan into the refrigeration compartment.
Circulation of air masses is carried out through special channels laid inside the case. If the upper chamber does not freeze, it means that one of the stages of this cycle is broken: either the air is not cooled, or does not enter the upper part, or the system “thinks” that the cold has already been reached. In dual-circuit systems (where there are two compressors), the situation is simpler - there is a separate circuit responsible for the top, and its failure indicates a problem in this particular unit.
The key element here is damper (damper). This is a mechanical curtain that opens and closes at the command of the electronics, regulating the flow of cold air. If the damper is stuck in the closed position, the freezer will operate normally, freezing food, and the cold simply will not flow into the upper compartment.
⚠️ Attention: In models with the system No Frost an attempt to forcefully open a frozen the flap can lead to breakage of the plastic gears of the mechanism. Do not use physical force without first defrosting.
It is also worth considering that some budget models use a drip system, where the cold is distributed due to natural convection. In such cases, leaking seals or improper loading of food can block the natural flow of air, creating “heat pockets” in the upper part.
Natural causes and operating errors
Before diagnosing a serious breakdown, it is worth eliminating factors that do not require the intervention of a technician. Often the reason lies in a banal violation of operating rules or a temporary failure. For example, if you have just loaded a large amount of warm food into the refrigerator, the system may not be able to cope with a sharp jump in temperature.
One of the most common reasons why the top does not freeze is overload with products. If you pack the shelves too tightly and block the vents, cool air won't be able to circulate. In such cases, even a working fan is powerless, since the flow is physically blocked.
- 📦 Layout violation: Products lie close to the back wall, blocking the outlet of cold air.
- 🧊 Icing of channels: In the No Frost system, rare defrosting leads to overgrowing of air ducts with ice.
- 🔌 Electronics failure: A short-term power surge could “hang” the control module.
Check whether the refrigerator door is pressed by a foreign object or piece packaging. Even a minimal gap results in a constant flow of warm, moist air, which condenses and freezes, blocking the system. Make sure that thermostat is not accidentally set to the minimum value.
If you find that food is frozen to the shelves or walls, and ventilation is impaired, try unloading the chamber by 20-30%. Leave some space at the back wall. Often this simple action restores normal operation without calling a specialist.
Technical faults: sensors and thermostats
If operating errors are excluded, attention should be switched to electronic components. In modern refrigerators, defrost sensors and thermostatsare responsible for the temperature. If the sensor that controls the temperature in the refrigerator compartment fails and shows a falsely high temperature, the compressor may not turn on or do not work long enough.
In models with electronic control, a problem with evaporator sensoris often encountered. It tells the control unit when to start and end the defrost cycle. If it is “lying,” the system may think that the evaporator is still warm and does not start the fan to supply cold to the upper chamber, although the freezer has already reached minus.
Diagnostics of the sensors requires a multimeter. It is necessary to “ring” the element for resistance at different temperatures. A discrepancy between the readings and the passport data indicates the need for replacement. This is a common problem in refrigerators Samsung and LG after 5-7 years of operation.
How to check the sensor without a multimeter?
Only the device will give the exact answer, but indirectly a malfunction can be suspected if the refrigerator behaves chaotically: it freezes heavily, then stops, or an error appears on the display (for example, code F5, F6 or similar, depending on the brand).
It is also worth checking the integrity of the wiring going to the sensors. Vibration of the compressor and temperature changes over time can lead to chafing of the insulation or oxidation of contacts in the connectors, which breaks the control circuit.
Problems with the defrosting system (No Frost)
The system No Frost (or Low Frost) eliminates manual defrosting, but adds components that can break. If the top does not freeze, and the fan in the back of the freezer is humming, but there is no cold, the drainage or air supply channels may be clogged. An ice plug in the channel is a frequent enemy.
Key elements of the defrost system, the failure of which is blocked by cold:
- ❄️ Defrost heating element: If it burns out, the evaporator becomes overgrown with a “fur coat” that blocks the channels.
- ⏱️ Defrost timer: A mechanical or electronic element that does not switch modes.
- 🔥 Thermal fuse: It burns out when the heating element overheats, opening the circuit.
When the evaporator is completely hidden under a layer of ice, the fan circulates air, but this air is not cooled, since heat exchange is disrupted by the ice crust. As a result, the freezer (where the evaporator itself is located) may be colder due to the proximity of the source, and warm air enters the upper compartment.
To solve the problem, it is often necessary to completely defrost the refrigerator within 24 hours with the doors open. If, after switching on, the problem returns after a week, it means that one of the elements of the defrost circuit is faulty and requires replacement.
☑️ Symptoms of a malfunction of the defrost system
Freon leak and problems with the compressor
The most serious reason why the top does not freeze is refrigerant leak. Freon circulates through a system of tubes. If micro-depressurization occurs (often in the foamed part of the case or in solder joints), gas becomes scarce. It is only enough for the first circuit (freezer), and it simply does not reach the second (refrigerator compartment), completely evaporating at the beginning of the journey.
Signs of a freon leak:
- 📉 Weak cooling: The freezer is working, but the food in it is soft, and at the top warm.
- 🔥 Hot condenser: The rear grill is only partially hot or, conversely, cold.
- 🔇 Quiet operation: The compressor operates almost silently or turns on for short periods.
Another possible reason is clogged capillary tube. The microscopic hole in the tube becomes clogged with oil breakdown products or moisture. The pressure in the system drops and the circulation of freon is disrupted. The symptoms are similar to a leak: the freezer is working, the refrigerator compartment is defrosting.
⚠️ Attention: Repairs related to finding leaks and refilling freon require special equipment and a license. Independent attempts to “add gas” can permanently damage the compressor.
In such cases, the technician pressurizes the system with nitrogen to find the location of the leak. If the tubes have rotted in the foamed part, sometimes you have to hang an external evaporator (weeping grille) on the back wall inside the chamber, which is an aesthetic compromise, but brings life back to the refrigerator.
Table: Comparison of symptoms and probable causes
For a quick diagnosis, use the following table. It will help narrow down the search for a fault before calling a technician.
| Symptom | Probable cause | Difficulty of repair | Can I do it myself |
|---|---|---|---|
| Warm at the top, warm at the bottom frost, no noise | Fan faulty | Low | Yes (replacement) |
| Warm at the top, compressor hot | Freon leak / Clog | High | No (requires a master) |
| Periodically turns off, warm at the top | Thermostat/sensor faulty | Medium | Yes (with a multimeter) |
| It hums, but there is no cold anywhere or weakly | The channels are clogged with ice (No Frost) | Low | Yes (defrost) |
| It’s cold only near rear wall | Air circulation is impaired | Minimal | Yes (rearranging products) |
Algorithm of actions and prevention
What to do if you encounter the problem described? Don't rush to buy a new refrigerator. Follow the step-by-step algorithm that will help localize the problem. First, do a complete defrost (at least 24 hours), even if you have No Frost. This will eliminate ice jams.
After turning on, listen to the operation of the fan. If it is silent when the compressor is running, the problem is in it or in its power supply circuit. Check temperature settings. Make sure that you have not turned on the “Super Freeze” or “Vacation” mode, which can block the operation of the refrigerator compartment to save energy.
Prevention of such problems is simple:
- Regularly (once a year) defrost the refrigerator completely.
- Monitor the condition of the door seals - they should fit tightly.
- Do not put hot foods inside.
- Clean the drainage hole (if any) from debris.
Remember that timely maintenance extends the life of the equipment. If simple methods do not help, and traces of oil are visible inside the chamber or a burning smell is heard, immediately unplug the device and contact a service center.
Why can’t you ignore the problem?
Operating a refrigerator with an incomplete cooling circuit (when the top does not freeze) causes the compressor to work without stopping. This leads to its overheating and burning of the winding, which is the most expensive breakdown, often unprofitable to repair.
Is it possible to use a refrigerator if the upper chamber does not freeze?
For a short time - yes, if you store products there that do not require deep cold, or move them to the freezer. However, continuous operation in this mode is dangerous for the compressor. It will work for wear, trying to compensate for heat leakage or lack of circulation, which can lead to its complete failure.
How much does it cost to repair if the upper chamber does not work?
The cost depends on the breakdown. Replacing the sensor or fan is relatively inexpensive. If leak detection, evacuation and refilling with freon are required, the price will increase 2-3 times. If the compressor burns out, repairs often become economically unfeasible for older models.
Why doesn’t the top freeze in a two-compressor refrigerator?
In such models, independent circuits are responsible for the refrigeration and freezer chambers. If the top does not freeze, then the problem is in the refrigeration chamber circuit: the second compressor, its start relay or thermostat could have failed. At the same time, the freezer works independently and properly.
How to understand that the defrost heating element has burned out?
Without a multimeter - only indirectly. Signs: an abundant “coat” of ice on the back wall inside the freezer, water flows out, and the upper chamber does not cool. An accurate diagnosis is made by testing the resistance circuit of the heating element.