The situation when food freezes in lower chamber the refrigerator and melts in the top is a classic sign of a malfunction of the cooling system. For owners of two-chamber models, this is a serious signal that requires immediate attention, since ignoring the problem can lead to complete damage to inventory and expensive compressor repairs. Most often, the root of evil lies in a violation of the circulation of the refrigerant or malfunction of the automation.
You should not panic ahead of time, but you also cannot postpone diagnostics until later. In some cases, the problem is solved by simple defrosting, in others, the intervention of a specialist with a manometric manifold is required. Modern refrigerators are designed so that the cold is generated in one place (usually in the freezer), and then distributed throughout the entire volume. If this process is disrupted, the upper section, being removed from the evaporator, is the first to suffer.
In this article we will analyze in detail the mechanical and electrical reasons why upper chamber loses cold, and we will create an action algorithm for independently identifying the breakdown. Understanding the operating principles of your model Indesit, Atlant or LG will help save time and money when calling a specialist.
⚠️ Attention: If you smell burning wiring or see sparking when you plug in the device, immediately stop any diagnostic attempts and disconnect the device from the power supply. Further operation is dangerous to life.
Checking the operating mode and tightness
Before looking for complex technical faults, it is necessary to eliminate trivial operating errors. Often, users accidentally activate the Super Freeze (Super Freeze) mode, which causes the compressor to work hard, freezing food in the freezer, but blocking the supply of cold air to the upper compartment. Check the control panel and make sure that the snowflake indicator or the corresponding icon is on.
The second critical point is the tightness of the doors. If sealing rubber the upper door is worn, dirty or deformed, warm air constantly enters the chamber. The cooling system does not have time to compensate for the heat gain, and the temperature inside rises. This is especially noticeable in the summer, when the temperature difference between the street and the refrigerator is maximum.
- 🧊 Check whether the mode vacation or
Ecois set, in which the upper chamber can operate in a gentle mode. - 🚪 Inspect the magnetic tape around the perimeter of the door for tears, food crumbs or grease deposits.
- 🌡️ Make sure that the products do not lie close to the back wall, blocking the air circulation channels.
If a visual inspection did not reveal any violations, and the refrigerator continues to work incorrectly, we move on to deeper diagnostics.
Mechanical damage and freon leakage
One of the most common reasons why the upper chamber stops freezing is a refrigerant leak. In two-chamber refrigerators with one compressor, freon first passes through the freezer, cooling it, and only then enters the circuit of the main compartment. If a microcrack has formed in the system, there is not enough gas to complete the full cycle, and it simply does not reach the top.
A leak can occur as a result of corrosion of the evaporator tubes (especially if you carelessly defrosted the refrigerator with a knife) or due to manufacturing defects in welds. In models with a foamed evaporator (built into the body wall), repairs are complicated and require installation of an external circuit. Diagnostics Leaks require the use of a leak detector and professional equipment.
⚠️ Attention: Independent refilling of the refrigerator with freon without finding and eliminating the leak is a temporary measure, which will lead to repeated failure in a few weeks or months.
How to understand that a leak has occurred? Pay attention to the operation of the compressor. If it hums continuously without turning off, and the freezer operates weakly or normally, but there is heat in the upper compartment, this is a sure sign of shortage refrigerant. Also, on the rear grille of the radiator, blistering paint or traces of oil may be visible, which indicates a place of depressurization.
Why can’t you ignore the operation of the compressor without stopping?
Continuous operation of the motor without rest cycles leads to overheating of the windings and thermal breakdown. As a result, the burnt-out compressor will have to be replaced entirely, which is up to 70% of the cost of a new refrigerator.
Clogged capillary tube
The capillary tube is a thin copper channel through which liquid freon under pressure enters the evaporator. Its diameter is so small that even a microscopic particle of moisture, oxide or technical dirt can completely block the flow of refrigerant. As a result, the pressure in the system drops, and the cold ceases to be produced or distributed unevenly.
Clogging often occurs after improper defrosting, when moisture from the chambers penetrates into the system, or during unqualified repairs, when the craftsmen did not use nitrogen when soldering. The symptoms of a blockage are very similar to a leak: the compressor runs for a long time, the condenser (grid at the back) is warm only at the outlet of the compressor, and the rest of the part is cold.
To eliminate this malfunction you need:
- 🔧 Evacuating the system to remove moisture and air.
- 💨 Blowing the capillary tube with nitrogen under high pressure.
- 🔄 Replacing the filter-drier, which retains moisture and dirt.
This procedure can only be done by a specialist with a vacuum pump and a nitrogen cylinder. Attempts to “blow out” the system yourself with your mouth or a tire pump will only drive moisture deeper into the system, turning a simple blockage into a complex chemical reaction with the formation of acids.
Malfunctions of the defrost system (No Frost)
In refrigerators with the system No Frost or Full No Frost freezing of ice on the evaporator hidden behind a plastic panel is a normal process. However, this ice must be thawed regularly. A defrost system consisting of a heating element, a defrost sensor (thermostat) and a timer (or electronic module) is responsible for this process. If one of these elements fails, the ice coat grows and blocks the cold air supply channels to the upper chamber.
Visually this may not be noticeable, since the evaporator is hidden. An indirect sign is the presence of puddles under the refrigerator (water overflowing the drain pan) or a block of ice visible through holes in the freezer. In this case, the compressor may turn on less often, since the air sensor in the chamber shows normal, but the circulation is blocked by ice.
The main elements that require checking:
- Defrost heating element —a heating element that melts the ice. It is called by a multimeter for resistance.
- Defrost sensor - opens the heating element circuit when the ice has melted. It may “stick” when open.
- Defrost timer is a mechanical or electronic device that switches the “cooling” and “defrost” modes.
☑️ Diagnostics of the No Frost system
If you find that the evaporator is frozen, try defrosting the refrigerator completely (for 24 hours with the doors open). If after switching on the cold appears and is distributed normally, but after 1-2 weeks the problem returns, it means that the defrosting system is faulty and requires replacement of components.
Failures in the operation of the thermostat and sensors
The thermostat (thermostat) is the “brain” that commands the compressor to turn on or off, based on the temperature in the chamber. In older models it is a mechanical “twist” with a capillary tube, in new ones it is electronic sensors. If the thermostat is “lying” and sends a signal that it is already cold in the upper chamber, the compressor simply will not start.
In two-chamber refrigerators with one compressor, the thermostat is usually installed in the upper chamber. If its sensitive tube has moved or the device itself has failed, the refrigerator may not turn on for days. You can check a mechanical thermostat by closing its contacts directly: if the compressor starts working and starts to freeze, the problem is in the regulator.
In models with electronic control (LG, Samsung, Bosch), air sensors are responsible for the temperature. Their readings can be seen in service mode or on the display (in some models). A sensor error is often displayed as a code on the screen.
| Symptom | Probable cause | Action |
|---|---|---|
| The compressor does not turn on | Thermostat or starter is faulty relay | Replacing a thermostat or relay |
| Works without stopping | Freon leak or blockage | Diagnostics of a sealed circuit |
| It turns on rarely, in ice in the freezer | Failure of the defrost system (No Frost) | Checking the heating element and timer |
| Clicks, but no start | The starting relay has burned out or the compressor is stuck | Replacing a relay or compressor |
Problems with the fan and damper
In refrigerators with forced air circulation (No Frost), cold is pumped into the chambers by a fan. If the fan impeller is frozen or the motor is burned out, air stops flowing into the upper chamber, remaining in the freezer compartment. A characteristic hum or complete absence of fan noise when the compressor is running will indicate this problem.
Also, in some models (for example, Indesit or Stinol with a “crying wall” system) a damper is installed that regulates the air flow. It may jam in the closed position due to ice or a mechanical defect in the drive. In this case, the freezer operates in normal mode, and the upper chamber remains warm.
For diagnostics it is necessary:
- ❄️ Defrost the refrigerator to prevent freezing of the fan blades.
- 🌀 Check the free movement of the air duct damper (if there is one in structure).
- 🔌 Ring the fan motor winding for a break.
⚠️ Attention: When working with the fan, make sure that the refrigerator is unplugged. Rotating blades can cause injury, and moisture entering the electrical contacts during defrosting will cause a short circuit.
Frequently asked questions (FAQ)
Why is everything frozen in the freezer, but warm in the refrigerator?
This is a classic sign of a freon leak or capillary tube clogged. There is only enough refrigerant for the first circuit (freezer), and it does not reach the upper compartment. It is also possible for the air ducts to freeze in No Frost systems.
Is it possible to operate the refrigerator if the upper chamber does not freeze?
For a short time - yes, if you put perishable foods in the freezer. However, prolonged operation in this mode is harmful to the compressor, which may work non-stop, trying to gain temperature. This will lead to its overheating and failure.
How long does it take to defrost the refrigerator to check?
To completely defrost the hidden cavities of the evaporator and thaw the ice in the channels, you must keep the refrigerator turned off with the doors open for at least 24 hours. A shorter defrosting may not eliminate the ice jam.
What to do if after defrosting the refrigerator started working, but after a week it stopped working again?
This indicates a malfunction of the automatic defrosting system (the heating element, timer or sensor has burned out). Ice builds up again and blocks the channels. A call to a technician is required to replace defective elements of the defrost system.
Could the reason be in the electronic control module?
Yes, a “burnt out” compressor or fan control triac on the board, as well as errors in the firmware can lead to incorrect operation. However, mechanical causes (leakage, blockage) are statistically more common.