The situation when the upper The refrigerator compartment stops cooling, while the freezer continues to operate normally, is a classic symptom of a malfunctioning No Frost system or a crying evaporator. This does not always mean that the unit is completely out of order, but it signals a disruption in the circulation of refrigerant or air inside the housing. The user often encounters the fact that the products in the main chamber begin to deteriorate, water appears on the shelves or, conversely, an ice crust forms, while in the freezer everything is frozen “to stone.”
The reasons for such an imbalance can vary from a banal clogged drainage channel to a serious freon leak in the evaporator. Modern two-chamber models, be it Indesit, Atlant or Beko, often use a single cooling system, where cold is generated in the freezer and forced or naturally transferred to the refrigeration compartment. If this process is disrupted, the temperature in the upper compartment begins to rise, reaching critical values.
In this article we will analyze in detail the mechanics of the operation of such systems, list the main breakdowns and tell you what actions you can take on your own and when you need to call a technician. Understanding the principle of operation will help you quickly diagnose the problem and avoid unnecessary diagnostic costs.
The principle of operation of two-chamber refrigerators
To understand why a temperature imbalance occurs, it is necessary to briefly consider the design of a typical household refrigerator. Most modern models use one compressor and one cooling circuit passing through both compartments. The refrigerant (freon) is compressed by the compressor, heated, passes through the condenser (grid at the back), cools and enters the evaporator. It is in the evaporator that freon boils and heat is removed from the chambers.
In systems No Frost the evaporator is usually hidden behind a plastic panel in the freezer. The fan drives cold air through the air ducts: some remains in the freezer, and some enters the refrigerator compartment through a damper. If the damper is stuck in the closed position or the damper motor is burned out, the cold simply does not reach the upper compartment.
In models with drip system (crying evaporator), cooling occurs due to natural convection or a separate evaporator in the upper part of the refrigerator compartment. Here, a common cause is freezing of the evaporator or a violation of the tightness of the circuit. It is important to note that in single-compressor models, a breakdown often affects both chambers, but at different rates of symptoms.
How does a dual-circuit system work?
In expensive models with two compressors or a Full No Frost system with two circuits, the chambers are independent. If you have just such a refrigerator, then the problem is localized strictly in the refrigeration chamber circuit: either the compressor burned out, or there was a leak in this particular circuit, or the thermostat/sensor of the upper compartment has failed.
Refrigerant leakage: the most common cause
One of the most likely reasons why it is warm in the refrigeration chamber, but in The freezer is cold, there is a partial leak of freon. This occurs due to microcracks in aluminum evaporators (especially in models with a foamed circuit) or corrosion of the condenser tubes. When the amount of gas in the system drops, its pressure is not enough to go full circle and cool the evaporator of the refrigerator compartment.
Freon simply does not reach the upper compartment, condensing and evaporating completely in the freezer. As a result, the freezer operates as usual (or even overloaded), and the temperature in the refrigerator gradually rises to room temperature. This process can last from several days to a couple of weeks until the user notices that the milk has turned sour and the meat has become soft.
⚠️ Attention: If you find an oily stain under the refrigerator or on the back wall, this is almost guaranteed to indicate a leak along with the compressor oil. It is impossible to fix this on your own; soldering and refilling are required.
Diagnostics of a leak requires special equipment. The technician checks the pressure in the system, pressurizes the circuit with nitrogen and looks for the location of damage. Leaks often occur in the sealing areas of the tubes or in the “crying” evaporators, which are located inside the foam insulation of the housing. In such cases, repairs can be complex and expensive, sometimes requiring the installation of an external evaporator.
Compressor malfunctions: working with one chamber
The compressor is the “heart” of the refrigerator, ensuring the circulation of the refrigerant. In some cases, especially in older models or when worn out, the compressor may lose its performance. It continues to hum and create pressure, but its power is not enough to pump freon through the entire cooling circuit.
In such a situation, there is only enough gas for the first section of the cycle - the freezer. The refrigerant simply does not reach the refrigerator compartment in the required volume and at the required pressure. It is also possible that one of the valves inside the compressor (discharge or suction) does not work correctly, which upsets the pressure balance in the system.
Signs of problems with the compressor may be:
- 🔊 The compressor works continuously, without turning off, trying to gain temperature.
- 🔥 Compressor housing may be excessively hot or, on the contrary, cold.
- 💧 The condenser (grid at the back) is heated only partially or unevenly.
- 📉 The temperature in the freezer may be slightly higher than normal (for example, -10°C instead of -18°C).
If the compressor is out completely out of order, it can hum, click (the starting relay is activated) and not start, or it can start for a few seconds and stall. In this case, the refrigerator will not freeze anywhere. However, the “sluggish” operation of the compressor is an insidious defect that disguises itself as normal for a long time.
Problems with the defrost system (for No Frost)
In No Frost refrigerators, the evaporator defrost system plays a critical role. Over time, a coat of ice builds up on the evaporator. Periodically (usually every 8-12 hours) it turns on Defrost heating elementwhich melts this ice. If one of the elements of this chain breaks, the ice stops melting and completely blocks the channels through which the fan should drive cold air into the fridge compartment.
It may be cold in the freezer, since the evaporator is located there, but the air flow into the upper chamber is blocked by an ice plug. The fan hums, but no air passes through. After a few days, the ice can reach the fan itself, blocking its blades, after which the sound will change or disappear.
The main elements of the defrost system that fail:
- ❄️ defrost heating element - burns out and stops heating.
- 🌡️ Defrost sensor (thermostat) —does not “see” the ice and does not give a command to turn on the heating element.
- ⏱️ Defrost timer (or electronic module)—does not switch the “cooling/defrost” modes.
For diagnostics, you need to defrost the refrigerator manually for 24 hours (unplug from the network with the doors open). If, after complete defrosting, the refrigerator started working normally and the cold entered the chamber, but after 1-2 weeks the problem returned, this is a 100% malfunction of the defrosting system.
Clogged capillary tube
The capillary tube is a very thin copper pipeline that serves as a choke in the cooling system. It is here that a sharp drop in freon pressure occurs, due to which it boils and cools the evaporator. The diameter of this tube is a fraction of a millimeter, so it is extremely sensitive to contamination.
The cause of the blockage may be moisture that entered the system during poor-quality repairs, or oil and metal oxidation products accumulated over years of operation. If the tube becomes clogged, freon cannot circulate fully. The pressure rises before the blockage, and then drops. As a result, the evaporator in the refrigeration chamber stops receiving cold agent.
Symptoms of a blockage are often confused with a freon leak, since the external manifestations are similar: the freezer freezes, but the chamber does not. However, if clogged, the compressor may operate more quietly or, conversely, overheat, and the condenser will be hot only in the first part. Only a specialist can make an accurate diagnosis by feeling the temperature of the tubes and analyzing the pressure.
Removing the blockage requires purging the system with nitrogen under high pressure, replacing the filter-drier and refilling with freon. This is a complex technical procedure that requires evacuation of the system.
Malfunctions of the thermostat and sensors
The refrigerator electronics control the temperature using sensors (thermistors) or mechanical thermostats. If the temperature sensor in the refrigerator compartment “lies” and shows the control module that it is already cold there (for example, -5°C instead of the real +10°C), the compressor simply will not turn on or will turn off too early.
In mechanical models, the thermostat is responsible for this. If its bellows tube has lost its tightness or the calibration has gone wrong, the contacts may not close. In modern electronically controlled models (LG, Samsung, Whirlpool), defrost sensors or air temperature sensors often fail.
Modern refrigerators often have a self-diagnosis function. If the sensor breaks down, error codes or flashing indicators may appear on the display. However, not all sensor faults are displayed on the screen. Some models, when the signal from the sensor is lost, go into emergency mode, where the compressor operates on a timer, which can lead to insufficient cooling of one of the chambers.
☑️ Primary diagnostics of electronics
Table: Comparison of symptoms of main breakdowns
For ease of diagnosis, we systematized the main symptoms of malfunctions. Please note that an accurate diagnosis requires a professional examination, but the table will help narrow down the search.
| Symptom | Freon leak | Capillary clogged | Defrost malfunction | Problem with the compressor |
|---|---|---|---|---|
| Freezer | Freezes, but weaker than usual | Freezes normally | Freezes normally | Freezes weakly or not freezing |
| Refrigerator compartment | Warm, food spoils | Warm, there may be ice on the back wall | Warm, no airflow | Warm |
| Compressor operation | Works non-stop | Works non-stop or with overheating | Works normally | Buzzes, clicks or is silent |
| Frost on the evaporator | Partial or absent | Uneven, only at the beginning | Solid block of ice | Absent or weak |
What you can do on your own and what you can’t
If you are faced with the problem described, do not panic. There are a number of actions that the user can perform safely, and a number of tasks that require specialist intervention. The main rule: do not try to disassemble a sealed circuit or change the compressor without skills and equipment.
What you can do yourself:
- 🧊 Complete defrosting. Unplug the refrigerator for 24 hours (preferably a day) with the doors open. This will eliminate the “snow coat” and ice plugs in the channels.
- 🧹 Cleaning the drainage. Check the hole for water drainage in the refrigerator compartment (usually at the bottom of the back wall). Clean it with a brush or soft wire.
- 🔌 Checking the power supply. Make sure that the plug is firmly seated in the socket and the voltage in the network is stable.
What to do ABSOLUTELY DON'T:
- 🚫 Pick around the evaporator. In No Frost models, the evaporator is often made of aluminum. One careless blow with a knife when chipping ice will pierce the tube, and the freon will instantly evaporate. Repair will become economically unfeasible.
- 🚫 Turn on the “heaters.” Do not heat the back wall with a hairdryer or boiling water to speed up defrosting. A sharp temperature change can damage the plastic and seals.
- 🚫 Change the freon yourself. This requires vacuuming the system. The remaining air and moisture will kill the compressor in a few months.
⚠️ Attention: If after 24 hours of defrosting the refrigerator turned on and began to freeze normally in both chambers, but after 1-2 weeks the problem repeated itself, this is a malfunction of the defrosting system (heating element, sensor, timer). This will not work on your own, you need a master.
Repairing the cooling system is a set of measures that requires precision. For example, replacing a compressor requires not only soldering, but also the selection of an analogue with similar characteristics (power, refrigerant, oil type). Using an unsuitable compressor will lead to rapid breakdown of the entire system.
How much does the repair cost?
The cost consists of the work of the technician, the cost of spare parts (heating element, sensor, compressor) and consumables (freon, oil, solder). Replacing a heating element is usually inexpensive, while replacing a compressor or fixing a leak in a foamed casing can cost up to 50-70% of the price of a new refrigerator.
Frequently asked questions (FAQ)
Why did the refrigerator work after defrosting, but a week later it stopped again?
This is a classic sign malfunction of the automatic defrost system. Ice has again accumulated on the evaporator and is blocking the air passages. Most likely, the defrost heating element, defrost sensor or timer has burned out. Diagnostics with a multimeter is required and replacement of the faulty element.
Is it possible to continue to operate the refrigerator if it is warm in the chamber?
For a short time - yes, but not recommended. The compressor will work hard, trying to gain temperature, which can lead to overheating and burning of the windings. In addition, food in a warm chamber will quickly spoil. It is better to turn off the device before the technician arrives.
How to understand that a freon leak has occurred?
Indirect signs: the compressor does not turn off, the refrigerator is warm inside, the condenser at the back is only partially warm or cold. Only a specialist can accurately determine a leak using a leak detector or nitrogen pressure testing.
Does the position of the temperature regulator affect the operation of the refrigerator?
Yes. If the regulator is set to minimum (slight cold), the chamber may be warmer than normal. Try switching it to maximum. If after 2-3 hours the temperature has not changed, the problem is technical, and not in the settings.
Is it worth repairing an old refrigerator or buying a new one?
If the refrigerator is more than 10-12 years old and the compressor needs to be replaced or a leak in the housing (foamed part) needs to be repaired, it is often more economical to buy new equipment. Repairs in such cases can account for the majority of the cost of a used appliance.