The situation when freezer compartment properly freezes food, but the main interior is warm, as if in the room, causing confusion and panic. Many users immediately begin to look for new models, believing that the equipment has completely failed. However, in most cases, the problem lies in specific components of the cooling system, which can be repaired or adjusted.
Modern Atlant refrigerators, Indesit, Bosch and other brands are often built using similar refrigerant circulation patterns. An imbalance of temperatures between chambers is a classic symptom indicating a malfunction of thermoregulation, ventilation problems or a working gas leak. Understanding the physics of the process will help you quickly diagnose a malfunction.
In this article we will analyze in detail the mechanics of operation of single-compressor and double-compressor systems. You'll learn why evaporator ice may form unevenly and how this affects the overall temperature in the refrigerator. It is important not to ignore the first signs, since prolonged operation in emergency mode can lead to compressor failure.
The principle of operation of the No Frost and drip defrosting system
To understand why the cold has disappeared in one of the chambers, you need to understand how exactly the air circulates inside the device. In models with the No Frost system, the cold is generated in a hidden evaporator, usually located behind the back wall of the freezer. Then the fan forcibly drives cooled air through special channels into the refrigeration compartment.
If the fan stops or the channels become clogged with ice chips, the cold stops flowing to the upper part. In drip systems (Direct Cool), the evaporator is located directly on the rear wall of the fridge compartment. Here the problem most often lies in a violation of heat removal or insufficient compressor power, which does not have time to drive freon through the full cycle.
It is important to note the difference in the operation of the sensors. In two-chamber models, one thermostat can control the temperature in the freezer, ignoring overheating in the refrigerator compartment. This creates the illusion of serviceability until the food in the main chamber begins to deteriorate.
Modern electronics often control flaps that regulate air flow. If the damper mechanism is stuck in the closed position, cold air cannot physically enter the desired compartment. Diagnostics of such systems requires checking not only the mechanics, but also electronic module controls.
Freon leakage: the most common scenario
One of the main reasons why freezer continues freezing, but the refrigerator is warm, there is a partial leak of refrigerant. Freon circulates in a closed circuit: first it passes through the freezer, giving off part of the cold there, and then enters the main compartment. If the gas in the system becomes less than normal, there is simply not enough gas for the second stage of the cycle.
Visually this can manifest itself in the form of swelling of the rear wall or the appearance of oily spots at the site of breakdown of the tubes. If there is a freon leak, the compressor works almost non-stop, trying to gain temperature, which leads to its overheating and high power consumption. Long-term operation in this mode is dangerous for the engine.
Leaks often occur in the foamed part of the housing or at the junction of the tubes with the evaporator. Finding the leak on your own is difficult because it requires special equipment to detect the refrigerant gas. Attempts to simply “add gas” without eliminating the cause of the hole in the circuit will only give a temporary effect.
⚠️ Attention: Freon is odorless and colorless (except for some brands with an additive), so it is impossible to detect a leak by smell. If you hear a hissing sound, this is already a critical emergency situation.
To eliminate this malfunction, the technician pressurizes the system with nitrogen, finds the place of depressurization, seals it and refills the refrigerator with a new portion of refrigerant. The filling volume is strictly regulated by the manufacturer for each model.
Malfunctions of the compressor and start relay
The compressor is the heart of the refrigerator, creating pressure for the movement of freon. In dual-circuit systems or under certain operating conditions, one compressor may lose performance. When the piston group wears out, the compressor may hum, but not create enough pressure to pump freon into the second chamber.
Often the problem lies in starting relay. This small element is responsible for starting the engine. If the relay is “stuck” or burnt out, the compressor may not start at all or may start for a few seconds and stall with a characteristic click. In some cases, a faulty relay passes current, but the engine does not operate at full capacity.
Symptoms of a compressor failure are often accompanied by severe heating of the motor housing. If you touch the rear grille or the engine itself, and it burns your hand, but there is no cold, this is an alarming signal. It is also worth paying attention to the sound: a steady hum is replaced by an intermittent, metallic clang or complete silence.
Replacing a compressor is a complex technical procedure that requires evacuation of the system and precise soldering of copper tubes. DIY Repair this is only possible with professional tools and skills in working with refrigeration equipment.
Problems with the thermostat and temperature sensors
The thermostat (thermostat) is a device that commands the compressor to turn on or off depending on the temperature inside the chamber. If this device fails or its capillary tube has moved, the refrigerator may “think” that the cold has already been collected and does not turn on cooling for the main chamber.
In electronic models, they are responsible for control temperature sensors (thermistors). Their resistance changes with temperature changes, and the control module reads these readings. If the sensor “lies” or shows an open circuit, the system goes into emergency mode or incorrectly controls the dampers and fan.
Checking a mechanical thermostat is possible at home. To do this, you need to remove it, immerse the sensitive tube in cold water and ring the contacts with a tester. When the tube is heated in your hands, you should hear a click, indicating that the circuit is open.
A common mistake is incorrect setting of the regulator. Users may accidentally set the minimum cooling power, which is enough for the freezer, but not enough for the main compartment in hot weather.
☑️ Diagnostics of the thermostat
Clogged capillary tube and ice plug
The capillary tube is the thinnest channel through which freon enters the evaporator under high pressure. The diameter of this channel is so small that even a microscopic particle of debris or frozen moisture can completely block the flow of refrigerant.
If clogged, freon cannot circulate throughout the entire circuit. It accumulates and freezes in front of the plug (usually this can be seen by swelling of the tube or local freezing), and then a vacuum goes through the system. As a result, the freezer can keep the cold for some time due to inertia, but the refrigeration compartment gets warmer.
Moisture in the system appears due to poor-quality filling or depressurization. At the point where the capillary narrows, the water freezes, forming an ice plug. A characteristic sign is cyclical operation: the refrigerator was working, the plug thawed - cold appeared, froze again - it disappeared.
Removing the blockage requires purging the system with nitrogen under high pressure and replacing the filter-drier. The filter retains moisture and mechanical impurities, and its replacement is required whenever the circuit is opened.
Why can't you ignore a blockage?
If you operate a refrigerator for a long time with a clogged capillary tube, the compressor works with overload, trying to push through the plug. This often leads to an interturn short circuit of the windings and combustion of the motor, which makes repairs economically unfeasible.
Faults in the defrost system (for No Frost)
In refrigerators with the system No Frost the proper operation of the evaporator defrost system is critically important. It consists of a heating element (heater), a timer (or electronic module), a defrost sensor and a thermal fuse. If any of these elements fails, the evaporator becomes covered with a “coat” of ice.
Ice blocks the operation of the fan and blocks the air supply channels. As a result, it is cold in the freezer (the frozen evaporator itself is located there), and cold air simply does not flow into the refrigerator. Outwardly, this may look like a swollen back wall in the freezer.
You can check the defrosting system visually by defrosting the refrigerator for 24 hours. If after complete defrosting the equipment worked normally, and a week later the problem returned, the diagnosis is confirmed. Most often, the heating element burns out or the defrost timer “sticks.”
It is also worth checking the drainage hole. If it is clogged with debris or ice, the water does not melt away, but freezes below, gradually blocking the path of air flow. Cleaning the drainage with soft wire or warm water often solves the problem.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor hums, but does not start | Faulty start relay or jammed compressor | Medium / High |
| There is cold, but poor cooling | Freon leak or capillary tube clogged | High (requires a technician) |
| Ice on the back wall of the freezer | The defrosting system is faulty (No Frost) | Medium |
| The refrigerator rarely turns on | Thermostat or sensor is faulty | Low / Medium |
Other reasons and external factors
The reason does not always lie in the breakdown of components. Sometimes operating conditions are to blame. For example, if the refrigerator is located close to the wall or in a niche without gaps for ventilation, heat exchange is disrupted. The compressor overheats and goes into protection, not having time to produce the necessary cold.
Damage to the sealing rubber on the door of the refrigeration chamber leads to a constant influx of warm, moist air. The system cannot cope with cooling a large volume of incoming heat, although a freezer whose door is opened less often can maintain temperature.
It is also worth checking the position of the air supply damper (if it is controlled by a mechanical slider inside the chamber). It could accidentally move to the "Minimum" position. In some models Samsung or LG the damper is controlled by a motor that could become jammed.
⚠️ Attention: Do not try to pick out the ice with a knife or sharp objects. A breakdown of the evaporator channel will lead to the immediate release of all freon and the entry of oil into the system, which will greatly increase the cost of repairs.
Check whether the chamber is not loaded too tightly with products. Air circulation must be free. If the products lie directly at the exit of the air channels, the cold physically cannot be distributed throughout the volume.
Frequently asked questions (FAQ)
Is it possible to continue using the refrigerator if there is no cold in one chamber?
Short-term operation is possible, but undesirable. If the cause is a freon leak, the compressor will wear out, which can lead to its complete combustion. If the problem is in the defrost system, the ice may damage the fan or plastic casing. It is better to turn off the equipment before the technician arrives.
How long does it take to defrost the refrigerator to check?
It takes at least 24 hours for the ice in the system to completely melt No Frost and evaporate moisture from hard-to-reach places. Defrosting for 2-3 hours is often not enough for the ice plug in the channels to completely disappear, which can lead to an erroneous diagnosis.
Why did the refrigerator start working after defrosting, but stopped again a week later?
This is a classic sign of a malfunction of the automatic defrosting system (the heating element, timer or sensor has burned out) or the presence of moisture in the system (freezes in capillary). Defrosting removes the symptom (ice), but does not cure the cause of its occurrence.
Is it possible to replace the thermostat yourself?
If you have a mechanically controlled refrigerator, replacing the thermostat is a procedure accessible to a person with basic skills. You just need to connect the contacts correctly and install the sensitive tube in its normal place. In electronic models, replacing sensors requires disassembling the case and skills in working with electronics.