The situation when a two-chamber refrigerator suddenly stops cooling the upper compartment, while the freezer continues to operate normally, is one of the most common complaints from owners of household appliances. You open the door, expecting to see cold, and there is food at room temperature, while in the freezer everything is frozen solid. This is a classic symptom of a refrigerant circulation problem or a malfunction in the temperature control system.
Such a malfunction cannot be ignored, as it can lead to damage to a large number of products and further, more expensive compressor repairs. Unlike situations where the refrigerator does not turn on at all or hums but does not freeze anywhere, here the system is partially functional, which narrows the range of potential causes. Most often, the problem lies in a freon leak, a clogged capillary tube, or a failure of the thermostat.
Before calling a technician or disassembling the unit, it is necessary to conduct an initial diagnosis to understand the scale of the problem. There is no need to panic: in many cases, repairs are possible on your own or require replacing an inexpensive element such as a thermostat or sensor. However, an accurate understanding of the physics of the process will help you avoid unnecessary expenses and correctly formulate the task for a specialist.
The principle of operation of a two-chamber cooling system
To understand why the cold disappeared in the main chamber, you need to understand exactly how it works cooling cycle in modern models. Double-compartment refrigerators typically use a single compressor to push the refrigerant, but the evaporators can be separated or combined into a single system with different temperature zones. In models with the system No Frost cold air is forced by a fan from the freezer into the refrigerator through special channels.
If the fan stops or the damper that regulates the air flow is stuck in the closed position, the cold simply does not enter the upper compartment. In simpler models with a “crying” evaporator, the refrigerant passes through a long circuit, first cooling the freezer and then rising. If there is little freon in the system, it is only enough for the first stage - freezing, and it no longer reaches the top in the required state of aggregation.
It is important to distinguish between types of cooling, since the troubleshooting algorithm depends on this. In Low Frost or classic drip systems, the problem may be freezing of the evaporator itself, which stops giving off cold.
How does the defrost cycle work?
In No Frost systems, the heating element is periodically turned on, which melts the ice on the evaporator. If the heating element burns out, the ice blocks the air supply channels, and the cold stops flowing into the refrigerator compartment, although the compressor hums properly.
Refrigerant leakage: the most common reason
The most likely reason that the refrigerator only freezes in the freezer is a banal one. freon leak. The refrigerant circulates in a closed circuit, and if a microscopic hole appears in the tubes or connections, the gas gradually evaporates. It becomes insufficient to create the pressure necessary to cool the large volume of the main chamber.
Leak symptoms appear gradually. At first, you may notice that the refrigerator began to work longer, the cycles of switching on became more frequent, and local areas of frost appeared on the back wall or, conversely, it became completely dry and warm. In this case, the compressor can work almost without interruption, trying to reach the set temperature, but to no avail.
⚠️ Attention: Self-filling the refrigerator with freon is prohibited and dangerous. This requires a vacuum pump, a pressure gauge station and precise knowledge of the type and weight of the refrigerant indicated on the technical plate.
Leaks are often located in the foamed part of the housing (internal circuit) or in the area of the door seal where the heating circuit passes. It is almost impossible to determine the location of the fistula visually without special equipment and ultraviolet illumination, unless dye is added to the system.
Clogged capillary tube and compressor operation
The second most common cause is clogged capillary tube. This is a thin copper channel in which a sharp drop in refrigerant pressure occurs and its evaporation. Over time, oil oxidation products, paraffin or moisture can accumulate inside the system, which turns into an ice plug.
When the tube becomes clogged, the compressor continues to pump freon, but circulation is disrupted. The pressure in the condenser increases and the pressure in the evaporator decreases. As a result, a freezer that is closer to the beginning of the cycle or has a separate circuit can still freeze while the main chamber remains warm. In such conditions, the compressor operates with overload and can become very hot.
A blockage can be diagnosed by the following signs:
- 🌡️ The condenser (grid at the back) is only partially or unevenly hot.
- 🔇 The compressor runs louder than usual or makes a metallic sound clanging.
- ❄️ The evaporator in the freezer is unevenly covered with frost, often only at the tube inlet.
To eliminate this problem, it is necessary to flush the system with nitrogen under high pressure and replace the filter-drier. This is a complex procedure that requires opening a sealed circuit.
☑️ Compressor diagnostics
Malfunctions of the thermostat and sensors
If everything is in order with the physical side of freon circulation, the problem may be in the “brains” of the refrigerator - the control system. Thermoregulator (thermostat) or electronic temperature sensor are responsible for turning off the compressor when the desired cold is reached. If the sensor in the refrigerator compartment “lies” and shows that it is already -10°C, the compressor simply will not turn on to cool the top, although it may be warm in the freezer.
However, in our case (the freezer is working, the top is not), the opposite situation is more common: the sensor is faulty mechanically or electrically, and the system does not receive signal about lack of cold in the upper compartment. In electronic models with a display, this will be indicated by an error code, which can be found in the instructions for the model Indesit, Atlant or LG.
Mechanical thermostats, which are a box with a lever inside the chamber, may lose the seal of the bellows. In this case, they require complete replacement. You can check them by closing the contacts directly: if the refrigerator then starts to freeze in both chambers, then the regulator is faulty.
Problems with defrosting in the No Frost system
In refrigerators with a system No Frost the lack of cold in the upper chamber when the freezer is running often indicates a failure in the defrosting system. If the heating element, timer or defrost sensor fails, the evaporator in the freezer becomes covered with ice. This ice blocks the operation of the fan, which should drive cold air upward.
Visually it may look like this: the freezer freezes very hard, food freezes to the shelves, but it is warm in the refrigerator compartment. An ice coat blocks the air ducts. Sometimes you can hear the fan trying to start, but the ice interferes with the blades, making a cracking or humming sound.
To solve the problem, you often need to completely defrost the refrigerator within 24 hours with the doors open. If, after switching on, the problem recurs after 1-2 weeks, it means that one of the elements of the defrost system (heating element, sensor, timer) requires replacement.
Comparative table of symptoms and solutions
To quickly navigate possible faults, it is convenient to use the summary table. It will help to weed out unlikely options and focus on the main thing.
| Symptom | Probable cause | Difficulty of repair | Necessary equipment |
|---|---|---|---|
| The compressor does not turn off, the top is warm | Freon leakage | High | Vacuumator, freon, burner |
| Humming, clicking, no cold top | Capillary clogged | High | Nitrogen, filter drier |
| The refrigerator does not turn on at all | Thermostat is faulty | Low | Multimeter, new thermostat |
| Frost only at the tube inlet | Lack of refrigerant | Medium | Pressure gauges, freon |
As can be seen from the table, most serious problems require the intervention of a professional. You can replace the thermostat yourself or carry out defrosting, but you shouldn’t get into a sealed circuit without experience.
What can you do yourself before the technician arrives
If you find a problem, do not rush to disassemble the back cover. There are a number of actions that will help facilitate diagnosis or temporarily save the situation. First, defrost the refrigerator completely. Unplug it, remove all food and leave it with the doors open for at least a day. This will prevent the formation of an ice plug in the capillary or channels.
Secondly, check the tightness of the door. If the seal is worn out or the door is warped, warm air constantly enters and the compressor cannot cope, creating the illusion of a breakdown. Also make sure that the food in the refrigerator compartment does not block the cold air outlets.
⚠️ Attention: Do not use sharp objects to chip ice inside the compartments. A puncture in the evaporator will lead to an immediate release of freon and will require expensive welding or replacement of the entire unit.
If, after defrosting and checking the tightness of the doors, the situation has not changed, and the compressor operates continuously, most likely, professional repairs will be required with evacuation and refilling of the system.
Frequently asked questions on the topic (FAQ)
Is it possible to operate a refrigerator if it does not freeze the upper chamber?
Short-term - yes, if you transfer perishable foods to the freezer or use them immediately. However, prolonged operation of the compressor idling (without shutting down) will lead to its overheating and eventual combustion of the windings, which will make repairs economically unfeasible.
How much does a repair cost if the cold in the refrigeration chamber has disappeared?
The cost depends on the reason. Replacing a thermostat or sensor is inexpensive. If it is necessary to search and eliminate the leak followed by refilling with freon, the price will be much higher, since this is a labor-intensive process that requires special equipment.
Why did the refrigerator start working normally after defrosting, but after a week stopped working again?
This is a classic sign of either a clogged capillary tube (the ice plug thawed and then formed again), or a system malfunction defrosting in No Frost models (the heating element or timer burned out, the ice again blocked the air channels).
Does the room temperature affect this problem?
Yes. If the room is too cold (below +10°C), the refrigerator may not turn on or freeze poorly, since the temperature difference is not sufficient for the thermostat to work correctly. In a hot room, the compressor may not be able to cope with the heat flow.