The situation when refrigerator compartment stops maintaining a low temperature, while the freezer compartment continues to operate normally, is a classic sign of a malfunction of the cooling system. This phenomenon often takes owners by surprise, because visually the compressor is humming, the light is on, but the food on the top shelf begins to deteriorate. This stratification of temperature conditions indicates that cold is generated, but is not delivered in the required volume to the upper section.
In most cases, the problem lies not in a complete breakdown of the unit, but in a disruption in the circulation of the refrigerant or a malfunction of the control electronics. Modern two-chamber models, be it Indesit, Atlant or LG, use a single cooling system, where the freezer is often the primary source of cold. If this chain is broken, the cold air simply does not reach the upper shelves, leaving them warm.
You should not panic right away, however, you cannot ignore the signal. Long-term operation of equipment in this mode can lead to compressor overload and more expensive repairs. Below we will analyze in detail the mechanics of the process, the main causes of failures and the algorithm of actions for diagnostics.
The principle of operation of a two-chamber refrigerator
To understand the essence of the problem, it is necessary to briefly consider the device refrigerant circulation. In classic "No Frost" and static type systems, cold is produced in the evaporator, which is most often located in the freezer. Then, using a fan or natural convection, the cooled air is supplied to the refrigerator compartment. If this process stops, the upper part remains warm.
The key element here is capillary tube the heat removal system. Freon, passing through the freezer evaporator, boils and takes away heat. After the compressor, it condenses in the condenser (grid at the back) and enters the system again. A violation at any stage after the freezer evaporator leads to the described symptom.
Why does the freezer work longer?
In some refrigerator models, the operating cycles are configured so that the main cold is stored in the freezer compartment and then distributed. If the air distribution system (dampers, channels) fails, the freezer continues to freeze “in reserve,” but no air enters the refrigeration section.
It is important to note that in models with one compressor and one cooling circuit, the breakdown is often systemic in nature. In 80% of cases, the cause is a blockage of the capillary pipeline or a freon leak in the refrigeration chamber circuit. This is a physical limitation that cannot be eliminated without the intervention of a technician.
The main reasons for the lack of cold in the upper chamber
There are several technical reasons why refrigerator compartment stops freezing. The first and most common is a refrigerant leak. Even a microscopic hole in the circuit means that the freon pressure is not enough to go through the entire cycle and cool the upper chamber. In this case, the freezer still maintains its temperature due to residual refrigerant or operating at maximum capacity, but the top is already warm.
The second reason is clogging of the capillary tube. In the oil and freon circulation system, over time, clots, paraffin plugs can form, or moisture can enter, which turns into an ice plug. This creates hydraulic resistance, and the refrigerant does not enter the evaporator of the refrigeration chamber in the required volume.
The third reason lies in the malfunction of thermostat or electronic control module. If the temperature sensor in the upper chamber “lies” and shows that it is already cold there, the compressor simply will not turn on to cool the upper compartment, although it may be warm in the freezer. Or, on the contrary, the system “thinks” that there is enough cold in the freezer and does not start a cycle for the upper compartment.
- ❄️ Freon leak due to corrosion or mechanical damage to the circuit.
- 🧊 Formation of an ice plug in the capillary tube due to moisture in the system.
- 🔧 Malfunction of the compressor, which does not create enough pressure.
- 🌬️ Breakdown of the blower fan (in No Frost systems), which does not drive air upward.
⚠️ Attention: If you hear that the compressor is running continuously without stopping, but there is no cold in the upper chamber, this is a sure sign of a leak or blockage. Do not leave the equipment in this mode for more than 2-3 days, so as not to burn the motor.
The system is worth mentioning separately No Frost. In such refrigerators, the cold is pumped by a fan through special channels. If these ducts become frozen or clogged with food, or if the damper that regulates air flow is broken, the upper chamber will remain warm. In this case, the freezer works properly, since the evaporator is located there.
Diagnostics: how to determine the type of malfunction
Before calling a technician, you can carry out an initial diagnosis. This will help you more accurately describe the problem to a specialist over the phone and get an idea of the cost of the work. First of all, pay attention to the operation of the compressor. If it turns on, runs for a while, turns off, and then turns on again, this is a normal cycle. If it hums constantly, this is a bad sign.
Check the back wall inside the refrigerator compartment. If it is covered with a “coat” of ice or, conversely, is absolutely dry and warm with the compressor running, these are different diagnoses. An ice coat may indicate problems with defrosting, and a dry, warm wall may indicate a lack of freon.
It is also worth listening to the sounds. A characteristic gurgling or hissing sound may indicate that there is freon in the system, but there is not enough of it, or it passes through a narrow blockage. Complete silence when the engine is running often indicates that the gas has completely evaporated.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor runs non-stop | Freon leak, blockage | High (needs a technician) |
| Ice on the back wall of the chamber | Faulty defrost system | Medium (replacement heating element/timer) |
| The refrigerator is silent, does not turn on | The compressor or start relay has burned out | High (replacement unit) |
| Heat only on the top shelf | Incorrect loading, damper failure | Low (setting) |
It is important to check the door sealing rubber bands. If the door of the upper chamber does not close tightly, warm air constantly enters there. The compressor will work hard, trying to cool the volume, but due to the constant influx of heat, the temperature will not drop to normal.
Problems with the defrost system in No Frost models
In refrigerators with the system No Frost ("without frost"), the problem is the lack of cold in the upper chamber when operating freezer is often associated with a violation of the evaporator defrost cycle. The evaporator in such models is hidden behind a plastic panel. If the defrost heating element, defrost temperature sensor or timer (control module) fails, ice builds up on the evaporator.
This ice blocks the ventilation ducts through which cold air should enter the refrigerator compartment. As a result, the fan hums, the freezer freezes (since it is next to the evaporator), and the main chamber is hot. Over time, ice can block the fan itself.
You can diagnose this problem by carefully removing the back panel in the freezer (if the design allows) or noticing that after complete defrosting the refrigerator starts working perfectly, but after 1-2 weeks the problem returns. This is a direct sign of a malfunction in the defrost system.
It is necessary to check the following elements:
- 🔥 The defrost heating element —the evaporator could burn out and not heat up.
- 🌡️ Defrost sensor —could “stick” and not give a command to turn on heating.
- ⏱️ Defrost timer —mechanical or electronic failure of the mode switch.
⚠️ Attention: Do not try to pick out the ice with a knife or sharp objects! You can damage the aluminum evaporator or pierce the freon channels, which will turn a simple repair into a complex refilling and soldering.
Refrigerant leakage and system blockages
The most unpleasant reason is freon leak. Modern refrigerators often have foam evaporators, where the refrigerant pipeline is built directly into the wall of the case. Metal corrosion or manufacturing defects lead to microcracks. Freon evaporates, and its pressure is not enough for two circuits. The freezer, being the first on the path of the refrigerant, still freezes, but the gas does not reach the top.
Clogged system is also a common enemy. During operation, decomposition products may appear in the compressor oil, or moisture may enter the system. A plug forms at the exit from the capillary tube (where the narrowest cross-section is). It can be paraffin (from oil) or icy (from moisture).
Repair in such cases requires professional equipment. The technician must:
- Find the leak (often this requires removing the foamed part or installing a new external evaporator).
- Purge the system with nitrogen to remove the blockage.
- Vacuum the system, removing air and moisture.
- Fill the refrigerator the exact amount of freon indicated on the tag.
It is worth noting that if your refrigerator is more than 10-12 years old, and it has a breakdown of the evaporator in the foamed part, repairs may not be economically feasible. Installing an external “crying” evaporator inside the chamber will solve the problem, but will reduce the useful volume and worsen the appearance.
Failures in electronic control and thermostats
In modern models with electronic control (Electrolux, Bosch, Samsung) sensors and (control module) are responsible for the temperature. If the temperature sensor in the refrigerator compartment fails and transmits incorrect data (for example, that it is -10°C, although in fact it is +15°C), the module simply will not give a command to cool.
There may also be a failure in the control module program. The “brains” of the refrigerator may freeze or incorrectly distribute the compressor operating time between the circuits. In two-compressor models (where each chamber has its own motor), the problem is simpler: most likely, it is the upper compressor or its starting relay that has burned out, while the lower one continues to work.
To diagnose electronics, it is often necessary to test the sensors with a multimeter. The resistance of the sensor changes depending on the temperature. If the device shows a break or short circuit, the part needs to be replaced. In some cases, resetting the error helps by disconnecting the refrigerator from the network for 15-20 minutes.
☑️ Initial check before calling a technician
What you can do yourself and what you can’t
If you find a problem, your actions must be consistent. First, rule out simple reasons: check whether the food has blocked the air flow, whether the door closes tightly, whether the temperature is set correctly (if the regulator is set to minimum). Try to defrost the refrigerator completely, leaving it turned off with the doors open for 24 hours.
If after defrosting and turning on the refrigerator worked normally, but a week later the problem recurred, the problem is in the defrosting system (heating element, sensor, timer). You can fix this yourself if you have the skills to work with a multimeter and a screwdriver by purchasing spare parts according to the model.
However, if defrosting did not help, or the refrigerator does not turn on at all, or the compressor works without stopping - call a specialist. Independent soldering of pipes, refilling with freon or replacing a compressor requires a license and special equipment. Unprofessional intervention can lead to a fire or permanent breakdown of the unit.
⚠️ Attention: Freon, although not toxic in small doses, upon contact with an open flame (soldering) forms poisonous phosgene gas. Work on a sealed circuit must be carried out in a ventilated area in compliance with safety regulations.
FAQ: Frequently asked questions
Can I continue to use the refrigerator if the top does not freeze?
Short-term - yes, you can move the food downstairs or use a cooler bag. But you cannot use the equipment for a long time: the compressor will work for wear without rest, which will lead to its burnout. Food in the upper chamber may also deteriorate.
Why did the refrigerator start to freeze after defrosting, and then stopped again?
This is a classic sign of a malfunction of the defrosting system (in No Frost models) or the presence of moisture in the system (ice jam). The ice melted during defrosting and allowed the system to work, but during the next cycle it formed again and blocked the channels.
How much does it cost to repair if freon leaks?
The cost depends on the location of the leak. If the tube is accessible, repairs are inexpensive. If the breakdown is in the foamed part of the housing, the installation of an external evaporator (“crying shelf”) will be required, which increases the cost of work and materials. In older models, repairs can cost up to 50-60% of the price of a new refrigerator.
How to understand that the compressor has burned out?
If the refrigerator is silent, the light is on, the temperature regulator is spinning, and the motor does not start (no buzzing or clicking) - the compressor or start relay may have burned out. Also a sign may be a burning smell or broken plugs in the panel when turned on.