The situation when the refrigerator compartment stops maintaining a low temperature, while the freezer compartment continues to function normally, is a classic symptom for a wide range of models of household appliances. Users often experience that food in the upper compartment begins to deteriorate, condensation appears on the shelves, and the temperature indicators flash, signaling a malfunction. At the same time, frozen products in the lower section remain hard, which creates a false impression of the health of the unit as a whole.
Such asymmetry in operation indicates a violation of the refrigerant circulation or a malfunction in the temperature control system. Unlike a complete compressor failure, when heat appears in all chambers, here the problem is local in nature. Double-circuit system or features of cold distribution in models No Frost can be the key to understanding what exactly has failed inside the housing.
It is not important ignore the first signs of unstable operation, since long-term operation in this mode can lead to compressor failure or a complete leak of freon. Modern refrigerators equipped with complex electronics that try to compensate for the loss of cold, causing the motor to work for wear. Understanding the physics of the process will help you make the right decision: call a technician or try to fix the problem yourself.
⚠️ Attention: If you hear an unusual hum or clicking when you try to start the compressor, immediately unplug the device. Further work may lead to a short circuit or fire of the wiring.
The principle of operation and distribution of cold in different systems
To understand why heat appears in only one compartment, you need to understand the structure of your refrigerator. There are two main types of design: single-compressor and dual-compressor models. In single-motor units, the cold is produced in the evaporator, which is usually located in the freezer, and then supplied by fan or natural convection to the refrigerator compartment. If this flow is blocked, the upper part stops freezing.
In two-compressor systems, a separate cooling circuit is responsible for each chamber. Here, the situation when the freezer works, but the refrigerator compartment does not, indicates a problem solely in the upper chamber circuit. This may be a malfunction of the own compressor for the refrigeration compartment, a freon leak in this particular circuit, or a failure of the temperature sensor, which does not give a start command.
Particular attention should be paid to the system No Frost, where the absence of ice is ensured by constant circulation of dry air. Fan, defrost heater i defrost sensor —three pillars that ensure stability. If one of these elements fails, the ice plug can block the air supply channels, and the cold simply will not reach the grocery shelves, remaining in the evaporator area.
It is also worth considering the age of the equipment. Older models with a single compressor often used a design where cold air flowed downwards by gravity. If the seal of the door is broken or the seal in the upper part is damaged, warm air constantly flows in, and the system does not have time to cool it, although the freezer located below can maintain the temperature due to inertia.
Mechanical damage and refrigerant leakage
One of the most common reasons for the loss of cold in one of the chambers is a violation the tightness of the system. Freon is a working fluid that circulates through the tubes, taking away heat. If a microcrack forms in the circuit responsible for the refrigeration compartment, the gas gradually evaporates. The pressure drops and the refrigerant stops boiling at the required temperature, which is why cooling stops.
Leakage can occur in hidden places: under the insulation layer, in the foamed part of the housing or at the junction of the pipes. It is difficult to detect this visually, but there are indirect signs. For example, if you notice that the condenser grilles at the back have become cold or, conversely, only partially heat up, this is a sure sign of a lack of gas. Also, swelling may appear on the walls of the chambers, indicating corrosion of the metal from the inside.
⚠️ Attention: An independent attempt to solder the tubes or refuel the refrigerator without evacuation of the system will lead to rapid failure of the compressor. Freon requires professional equipment for injection.
In double-circuit systems, the leak is often localized in the evaporator of the refrigeration chamber, which can be built into the wall. If this element is damaged, repair often requires replacing the entire evaporator or installing an external mounted evaporator ("crying"), which is a labor-intensive procedure. If the system is single-compressor, then a leak in the external circuit (where the freezer is located) is less likely; if the cold remains there, most likely the problem is a clogged capillary tube.
How do craftsmen find a leak?
Experts use leak detectors that respond to the specific smell of freon, or immerse dismantled components in water, monitoring the release of air bubbles. The nitrogen pressure test method is also used, when gas is pumped into the system at high pressure and the drop in pressure gauge readings is monitored.
Clogged capillary tube and ice plug
The capillary tube is a thin copper channel through which liquid freon enters the evaporator. Its diameter is so small that even a microscopic particle of moisture, oil or filter breakdown products can cause blockage. As a result, the so-called hydraulic blockageappears. The compressor tries to push the refrigerant, it hums, but the circulation is disrupted and the cold does not enter the chamber.
Often the blockage is temporary and is caused by the freezing of moisture inside the tube. This happens if there is excess moisture in the system that was not removed during a previous repair or due to prolonged operation with the door open. An ice plug forms at the narrowest point, blocking the freon flow. A few hours after turning off the refrigerator, the ice melts and the appliance may start working again, but soon the problem repeats.
To diagnose a blockage, technicians often use the method of tapping or heating the entry point of the capillary tube into the evaporator. If, after short-term heating, a characteristic sound of passing gas is heard (“whispering”), it means that the plug has been temporarily removed. However, to completely solve the problem, it is necessary blowing the system nitrogen and replacing the filter-drier, which is precisely designed to trap moisture.
| Symptom | Probable cause | Characteristic sign |
|---|---|---|
| The refrigerator hums, but does not freeze | Clogged capillary tube | The condenser is hot only at the compressor |
| The freezer is working, the top is warm | Freon leak in the refrigerator circuit | Bloating of the wall or traces of oil |
| Periodic on/off | Malfunction of the thermostat | No click when turning the regulator |
| Ice on the back wall | Malfunction of the defrost system | Increasing "fur coat" even in No Frost |
Faults of the defrost system in No Frost refrigerators
If you have a model with the system No Frostthen the absence cold in the upper chamber when the freezer is running is often associated with a violation of the evaporator defrost cycle. In such refrigerators, a fan drives air through an evaporator hidden behind a plastic panel. If the defrost heating element is burnt out or the timer is jammed, the evaporator becomes overgrown with ice, which blocks the air channels.
The air simply stops circulating, remaining in the freezer area, and does not enter the refrigerator compartment. Visually, this may manifest itself in the fact that the back wall in the refrigerator compartment does not cry, but remains dry and warm, while barely noticeable warm air may blow from the ventilation holes. Sometimes you can hear the fan trying to work, but the ice interferes with the blades, making a cracking sound.
To check, you need to get to the evaporator. To do this, remove the back panel in the freezer compartment (or in the refrigerator compartment, depending on the design). If you see a thick layer of ice blocking the radiator honeycombs, it means that the defrosting system did not work. It is necessary to check the integrity of Heating element, defrost sensor and fuse. Often it is enough to replace one of these elements to restore circulation.
☑️ Diagnostics of the No Frost system
It is worth noting that in some models the electronic control module is responsible for defrosting. If the triac that controls the heating element burns out on the control board itself, then mechanically replacing the elements in the chamber will not help. In this case, repair or replacement is required electronic board, which is a more expensive procedure.
Problems with the thermostat and temperature sensors
The thermostat (thermostat) is a device that closes and opens electrical circuit of the compressor depending on the temperature in the chamber. If it is faulty, it may “think” that it is already cold in the refrigerator and not give the command to turn it on. Double-compartment refrigerators often have two thermostats: one for the freezer and one for the refrigerator compartment. Failure of the upper thermostat leads to exactly the problem described.
Modern models use electronic sensors (thermistors) instead of mechanical thermostats. Their resistance changes with temperature, and this data is read by the control module. If the sensor “lies” or has an open circuit, the electronics blocks the start of the compressor or fan. The error is often recorded in memory, and fault codes may light up on the display, for example F1, E2 or flashing indicators.
You can check a mechanical thermostat by closing its contacts directly. If the refrigerator started working after that and started freezing, the reason has been found. It’s more complicated with electronic sensors: you need to “ring” them with a multimeter at different temperatures and check the readings with a resistance table for a specific model. Incorrect readings, even by 10-15%, can disrupt the controller’s operating algorithm.
⚠️ Attention: Technical characteristics of sensors and error codes are unique for each brand. What is normal for Liebherrmay be a critical error for Indesit. Always check the technical documentation.
Failures in the operation of the electronic control module
The electronic “brain” of the refrigerator coordinates the operation of all components. Voltage surges in the network, moisture ingress, or simply natural wear and tear of components can lead to malfunctions. In this case, mechanically serviceable components (compressor, fan, heating element) do not receive voltage. The module can supply voltage to the freezer compartment, but block the supply of current to the refrigerator compartment circuit.
Often such failures are accompanied by chaotic display behavior: all the lights blink, temperature settings are reset, or the device behaves unpredictably. Repairing the module requires the qualifications of a radio engineer. It is necessary to check the power switches, capacitors and board tracks for microcracks or traces of burning.
Sometimes the problem is solved by a simple reboot. Disconnecting the refrigerator from the network for 15-20 minutes allows you to reset errors in the controller’s memory. If after switching on the operating mode returned to normal, it means that the failure was a one-time failure caused by a power surge. If the problem returns, an in-depth diagnosis of the electronics is required.
Frequent questions and answers (FAQ)
Is it possible to continue to operate the refrigerator if the upper chamber does not freeze?
Short-term operation is possible, but not recommended. The food in the refrigerator compartment will quickly deteriorate, and the compressor will work in increased mode, trying to reach the set temperature, which will lead to its overheating and eventual breakdown. It is better to temporarily transfer the food to another place.
Why did the refrigerator work after defrosting, but a week later the problem recurred?
This is a classic sign of a capillary tube being clogged with moisture or a malfunction of the defrosting system. Defrosting removes the ice plug temporarily, but the cause (moisture in the system or a burnt heating element) does not go away. Professional repairs are required with replacement of the filter-drier or defrost elements.
How much does the repair cost if you need to refill with freon?
The cost consists of the price of the refrigerant, the work of the technician and the cost of the visit. Depending on the region and model of the refrigerator, refilling and leak detection can cost from 30% to 60% of the cost of a new budget refrigerator. The exact price will be announced only after diagnostics.
Is it possible to replace the thermostat yourself?
If you have a mechanical thermostat and have the skills to work with tools, yes. It is important to choose the right analogue according to the temperature range of operation. In electronic models, replacing sensors requires disassembling the case and often reflashing or configuring the module, which is best left to the pros.