Situation, when the freezer continues to freeze food properly, but the main compartment of the refrigerator suddenly becomes warm, this is familiar to many owners of household appliances. This is a classic symptom that immediately indicates a refrigerant circulation problem or a malfunction in the temperature control system. Users often mistakenly believe that since the compressor is humming and the freezer is working, then everything is fine with the unit, but this is a dangerous misconception.
Ignoring the problem at an early stage can lead to complete damage to the products in the main compartment and further failure of expensive components, such as compressor. In modern models with a No Frost or drip defrosting system, the reasons may vary significantly, but the principle of operation of the refrigeration circuit remains the same for most brands, be it a Indesit, Atlant or LG.
In this article we will analyze in detail the mechanical and electrical reasons for this temperature imbalance. You will find out why freon the supply to the main compartment evaporator stops and which parts require immediate replacement. Understanding the physical processes occurring inside the case will help you make the right decision: call a technician or try to fix the problem yourself.
The principle of operation of a two-chamber refrigerator and the role of the refrigerant
To understand why there is heat in one compartment and cold in the other, it is necessary to briefly consider the pattern of movement of the refrigerant. Most dual-compartment models use a series evaporator connection or a system with one common evaporator located in the freezer compartment. Cold air is blown by a fan through special channels into the main compartment. If this flow is disrupted, the temperature in the upper chamber begins to rise.
The key element here is refrigerantwhich, circulating through the tubes, takes heat from the chambers. In systems with No Frost the fan and damper system are responsible for the distribution of cold. If the fan stops or the damper is stuck in the closed position, the cold simply does not reach the food in the refrigerator, remaining only in the freezer.
⚠️ Attention: Attempts to independently open a sealed circuit to refill freon without special equipment and a license are prohibited by the legislation of many countries and can be dangerous for health.
It is important to distinguish between designs: in old models of the “crying” type, the evaporator is often located in the upper part, and the cold falls down by natural convection. In more modern units this process is forced. Malfunction of any element of the chain - from the defrost sensor to the damper motor - leads to the problem described.
Freon leakage: the most common diagnosis
The most likely reason that the freezer is freezing and the refrigerator is warm is partial refrigerant leakage. When the amount of freon in the system decreases, it is only enough for the first section of circulation - the evaporator of the freezer. The refrigerant simply does not reach the main compartment, as it completely evaporates ahead of time.
Leaks often occur in places where pipes are soldered or in the foamed part of the case due to corrosion. It is impossible to notice this visually, since freon is a colorless and odorless gas. An indirect sign may be that the compressor works almost non-stop, trying to gain temperature, but the condenser (grid at the back) remains barely warm or cold.
Long-term operation of the compressor in underload mode or, conversely, overheating due to an attempt to compensate for the lack of freon leads to its rapid wear. Therefore, if signs of a leak are detected, it is necessary to stop using the equipment as soon as possible.
To confirm the diagnosis, a pressure gauge station is required. The technician pierces the process fitting, checks for the presence of pressure and, if there is none, looks for a leak using a leak detector or nitrogen. After eliminating the hole, the system is evacuated and filled with new gas strictly according to the weight indicated on the nameplate.
Clogged capillary tube: ice or mud plug
The second most common cause of circulation problems is clogged capillary tube. This thin copper tube connects the condenser and evaporator, creating the necessary throttling (pressure drop). If a plug forms inside, freon cannot pass further than the freezer.
Clogs are divided into two types: ice and mud. An ice plug occurs due to moisture entering the system, which freezes at the narrowest point of the capillary. A mud blockage is the result of the ingress of corrosion products, oil or debris during poor-quality previous repairs. In both cases, the result is the same: the freezer works, the refrigerator does not.
How to distinguish a blockage from a leak?
If a blockage occurs, the compressor may operate cyclically or be very hot, and the condenser is heated unevenly (to the point of the blockage). When there is a leak, the compressor often runs non-stop and the condenser is cold. Only a master can make an accurate diagnosis.
Removing a blockage is a complex technical process. An ice plug can sometimes be “broken” by heating, but this is a temporary measure. A dirt blockage requires high-pressure nitrogen purging or replacement of the filter drier and part of the capillary tube. It is impossible to carry out this operation independently without a compressor and tools.
Malfunctions of the defrost system in No Frost refrigerators
In units with the system No Frost the problem often lies not in a leak, but in freezing of the evaporator. If the automatic defrost system malfunctions, ice builds up on the radiator in the freezer and blocks the channels through which cold air should flow into the upper chamber. Visually, it may be cold in the freezer, but there is no air circulation.
Three main elements are responsible for the defrosting process: Evaporator heating element, defrost sensor (defroster) and timer (or electronic control module). If the heating element burns out, the ice does not melt. If the sensor is faulty, the module “does not know” that it is time to turn on the heating. If the timer is broken, the defrost cycle simply does not begin.
☑️ Diagnostics of the No Frost system
To check this version, it is often enough to defrost the refrigerator manually for 24 hours (with doors open). If, after switching on, cold appeared in both chambers, but after 1–2 weeks the problem returned, the defrosting system is to blame. The burnt element needs to be replaced.
Problems with the thermostat and air damper
In some models, especially with two compressors or a complex air flow control system, the air damper is responsible for supplying cold to the main chamber. It is controlled by a motor and opens on command from a thermostat or electronic sensor. If the damper is stuck in the closed position or the motor that drives it burns out, the cold remains in the freezer.
Also the cause may be a malfunction of the thermostat (thermostat) itself. This device measures the temperature in the chamber and commands the compressor to turn on or off. If its sensing tube has moved or the contacts are stuck, the refrigerator may “think” that it is already cold in the chamber and not start the cooling cycle for the upper compartment.
In electronic models, control moduleis responsible for everything. A failure in its program or failure of the temperature sensor in the main chamber (NTC sensor) leads to the fact that the board does not supply voltage to the blower fan or damper. Diagnostics requires testing the sensors with a multimeter at different temperatures.
⚠️ Attention: When replacing a thermostat or sensors, it is important to use original spare parts or complete analogues with identical characteristics. Installing an unsuitable sensor will result in the refrigerator not operating correctly.
Table: Comparison of symptoms of main malfunctions
For ease of diagnosis, we offer a summary table that will help you navigate the possible causes of failure based on external signs.
| Malfunction | Compressor operation | Condenser temperature (rear) | Freezer status | Refrigerator compartment status |
|---|---|---|---|---|
| Freon leakage | Works without stopping | Cold or barely warm | Freezing slightly or normally | Warm, food spoils |
| Capillary clogged | Operates with overload or cyclically | Hot to the point of blockage, then cold | Freezing | Heat |
| Defrost failure (No Frost) | Operating in normal mode | Hot | Freezing, but there may be a lot of ice | Heat due to lack of airflow |
| Faulty damper | Working normally | Hot | Freezes perfectly | Warm, no air flow |
What you can do yourself and what you can do by a professional
If you find that the refrigerator is warm and the freezer is working, start with simple steps. First, check whether the food has blocked the airflow channels. Secondly, completely defrost the unit within 24 hours. This will eliminate ice blockage in the No Frost system. If after defrosting and restarting the problem returns after a couple of days, you cannot do without a specialist.
You can replace the thermostat yourself (if it is available and similar to yours), clean the drainage hole or replace the light bulb. However, any actions related to refrigeration circuit (soldering, refilling with freon, replacing the compressor) require a license, expensive equipment and special skills.
Attempts to “save” by calling a technician in the event of a freon leak often lead to the purchase of a new refrigerator, since unqualified intervention can finish off the compressor. Remember that high-quality repairs with a guarantee are always cheaper than buying new equipment.
Frequently asked questions (FAQ)
Is it possible to temporarily use a refrigerator if the freezer is working and it is warm in the main chamber?
For a short time - yes, food can be transferred to the freezer. However, continued operation in this mode is harmful to the compressor, which wears out. In addition, bacteria will quickly multiply in a warm chamber.
Why did the refrigerator work after defrosting, but after a week it stopped again?
This is a classic sign of a malfunction of the defrost system in models No Frost. Ice builds up again on the evaporator and blocks the channels. Replacement of the heating element, sensor or timer is required.
How much does refilling with freon cost and is it worth repairing an old refrigerator?
The cost depends on the region and model; usually repairs with refilling make up a significant part of the price of a new budget refrigerator. If the unit is more than 10–12 years old, it is often more advisable to consider purchasing new equipment, since the life of other components is also coming to an end.
Does the compressor hum louder than usual when there is a freon leak?
Not necessarily louder, but the nature of the operation changes. It can work continuously without shutting down. In some cases, with a strong leak, the sound may become duller or, conversely, a whistle may appear at the gas outlet (although it is difficult to hear).