The situation when the upper chamber refrigerator stops cooling food causes panic in any home cook, because this is a direct threat to the safety of the food supply. Often, owners notice the problem too late, when the meat has already begun to spoil, and ice has formed in the freezer or, conversely, everything has melted. In two-chamber models, a violation of the temperature regime in one compartment inevitably affects the operation of the entire system.
Modern units, whether reliable Bosch or popular Indesit, are designed so that the cold is distributed unevenly during failures. If you find that it is warm in the upper compartment, but everything is frozen below, or the temperature has risen everywhere, but in different ways, it is urgent to carry out an initial diagnosis. Ignoring the first symptoms can lead to costly repairs compressor.
In this article we will analyze in detail the mechanical and electrical causes of malfunctions so that you can understand the scale of the problem. You don't have to be an engineer to determine whether a professional needs to be called in or if the situation can be corrected yourself. The main thing is to act consistently and not ignore the obvious signs of breakdown.
The principle of operation of the cooling system and the distribution of cold
To understand why the upper chamber stopped freezing, you need to briefly refresh your memory of the basic principle of operation of the refrigeration circuit. The refrigerant (freon), circulating through the system, takes heat from the internal space and releases it to the environment through the condenser. In classic models without a system No Frost cold air, being heavier, sinks down, and warm air rises up, creating natural convection.
However, if it is warm in the upper compartment, this often indicates a violation of the refrigerant circulation or failures in temperature control. In models with one compressor the cold first enters the freezer compartment, and then, according to the residual principle, cools the refrigerator compartment. If there is little freon or the system is clogged, there is simply not enough cold for the upper tier.
In units with a system No Frost everything is more complicated: fans work here, which force air through the evaporator. If fan stopped or the air ducts are clogged, the cold does not physically enter the upper part of the chamber, even if the compressor is working properly and humming.
⚠️ Attention: In models with one compressor and one cooling circuit, the freezer compartment is always cooled more intensely. If the temperature in it is normal, but the temperature in the refrigerator is not, the problem almost always lies in the cold distribution system or control, and not in a complete leak of freon.
Understanding the structure of your refrigerator helps to narrow down the search. For example, in two-compressor models (a separate motor for each compartment), the problem is local: if the top does not freeze, it means that the upper circuit or its thermostat is faulty, and the lower one can work perfectly.
Malfunctions of the thermostat and temperature sensors
One of the most common reasons why the upper chamber does not cool is the failure of building thermostat (thermostat). This device is responsible for turning the compressor on and off depending on the temperature inside the chamber. If its contacts are stuck in the “off” position or it has lost sensitivity, the compressor simply will not start and the temperature will begin to rise.
In modern models with electronic control, the role of a mechanical thermostat is performed temperature sensors (thermistors). They transmit a signal to the control module. If the sensor is lying and shows that the chamber is already -20°C, although it is +10°C, the module will not give a command to cool. Replacing such an element often requires disassembling the internal panel.
Diagnostics of a mechanical thermostat is possible at home. It is usually located inside the refrigerator compartment or outside, near the compressor. If, when you turn the thermostat knob, you do not hear a characteristic click, and the compressor is silent, there is a high probability of its breakdown.
- 🔌 The absence of a click when turning the thermostat knob indicates a mechanical breakdown of the internal contacts.
- 🌡️ Distorted readings on the display (if any) may indicate a malfunction of the electronic sensor.
- ❄️ The compressor works without stopping, but the temperature does not drop - the thermostat is "stuck" in the "on" position, but does not control the cycle correctly.
It is important to note that in some models LG and Samsung sensors may cause an error, which can count by the blinking indicators. In this case, professional diagnostics with a multimeter is required to measure the resistance.
Problems with the compressor and start relay
Compressor is the heart of the refrigerator, and if it does not “pull”, the cold is not produced anywhere, but sometimes symptoms appear selectively. If the compressor turns on for a couple of seconds, makes a clicking sound and turns off, most likely the problem is in the start relay or the motor itself. In this mode, it does not have time to create the pressure necessary to circulate freon throughout the entire circuit, and the cold does not reach the upper chamber.
If the motor hums constantly without turning off, but the temperature in the upper compartment is higher than normal, this may indicate a loss of compressor performance. Mechanical wear of the piston group does not allow sufficient pressure to be generated. In this case, even a working circuit will not be able to properly cool the products.
The starting relay is a small block that is attached to the side of the compressor. This is what gives the starting impulse. If the relay is burned out, the compressor will not start. You can check it visually (presence of burning, melting) or “hearing” (no start click).
⚠️ Attention: If the compressor is hot to the touch, but does not start or works intermittently, do not try to start it repeatedly. This can lead to permanent burnout of the motor windings and expensive repairs.
In rare cases, the problem may be in the wiring going to the compressor. Oxidized contacts or a broken wire can interrupt the power circuit, causing the unit to operate incorrectly.
Refrigerant leak and clogged capillary tube
These two technical faults often go hand in hand in the list of reasons why the upper chamber does not freeze. Freon leak is a violation of the tightness contour. The refrigerant evaporates and there is not enough of it to complete the entire cooling cycle. As a result, the evaporator in the freezer is still cold, and the freon reaches the upper compartment either warm or not at all.
Clogged capillary tube is a mechanical blockage of a narrow section of the pipeline with oil oxidation products or moisture (ice blockage). Freon cannot circulate, the pressure in the system drops, and cooling stops. Often, when there is a blockage, you can hear an unusual gurgle or whistle when the compressor is operating.
The symptoms of these problems are similar: the compressor runs for a long time or constantly, but there is not enough cold. On the back wall of the freezer, only partial “snow” or ice may appear only at the entrance of the tubes, and the rest of the surface remains warm.
| Symptom | Freon leakage | Capillary clogged |
|---|---|---|
| Operation compressor | Works without stopping | Works with overheating, may hum |
| Condenser (grid at the back) | Warm only at the beginning or cold | Hot, but no circulation |
| Evaporator | Partially covered with frost | Unevenly covered with frost |
| Sound | No noise | Possible gurgling or whistling |
It is impossible to eliminate these faults on your own. It is necessary to evacuate the system, search for a leak (often a foamed housing) or purge the circuit with nitrogen. This is a job for a master with equipment.
Is it possible to fill a refrigerator with freon yourself?
From a technical point of view, if you have equipment (a pressure gauge station, a vacuum pump, scales), this is possible. However, without finding the cause of the leak, refilling will only give a temporary effect. In addition, different types of freon (R134a, R600a) require different oils and procedures. R600a is explosive, so working with it requires special care and ventilation.
Failures in the No Frost system and fan
If you have a modern refrigerator with a system No Frostthen the lack of cold in the upper chamber when the compressor is running often indicates a problem with air circulation. The fanlocated in the freezer is responsible for this. It drives air through the evaporator and directs flows into the refrigeration compartment through special channels.
If the fan is frozen in an ice crust or its motor is burned out, cold air remains in the freezer, and only room air enters the upper compartment. As a result, everything in the freezer is frozen solid, and there is heat on top. The air ducts themselves are also often clogged with ice.
Another common problem with the system No Frost is a malfunction of the defrost system. If Defrost heating element, the timer or defrost sensor fails, the evaporator becomes overgrown with ice. The fan cannot break through the ice coat, and circulation stops. Outwardly, it may look like a normally working refrigerator that has simply stopped cooling.
- 🌀 Check whether the fan spins when the doors are opened (in some models it is visible).
- 🧊 The presence of a thick layer of ice on the back wall of the freezer when the fan is running indicates problems with defrost.
- 🔇 If the fan hums but does not spin, it may be jammed with ice or the bearing bushing has failed.
Diagnostics often require completely defrosting the refrigerator within 24 hours. If after turning on the problem went away for a week and then returned, the defrosting system (heating element, sensor or timer) is definitely faulty.
☑️ Diagnostics of the No Frost system
Mechanical damage and leakage
Sometimes the reason is trivial and lies in the violation of the seal of the chamber. If sealing rubber the door of the upper chamber is worn out, dirty or deformed, warm air constantly flows inside. The compressor tries to compensate for the heat, working for wear, but cannot cope with the volume.
It is also worth checking whether the drainage channel is frozen. If the condensation does not go away, it freezes and can block the access of cold air or, conversely, create excess humidity, which turns into ice jams. Mechanical damage to the housing, dents after transportation can also damage the internal tubes.
Improper operation, such as loading hot products or frequently opening doors, creates excess stress on the system. In combination with the (old) seal, this quickly leads to an increase in the temperature in the chamber.
⚠️ Attention: If you notice that the door does not fit tightly, do not ignore it. Even a small gap of 1-2 mm significantly reduces the cooling efficiency and leads to the formation of a “coat” of ice, which blocks heat transfer.
You can check the tightness in a simple way: hold a sheet of paper with a door and try to pull it out. If the paper is easily removed without resistance along the entire perimeter, it’s time to change the rubber band or adjust the door hinges.
Frequently asked questions (FAQ)
Why is everything frozen in the freezer, but warm in the refrigerator?
This is a classic symptom of a refrigerant circulation problem (lack of freon due to a leak) or a clogged capillary tube. It is also possible that in No Frost systems the air supply duct is frozen or the fan is broken. The compressor works, but there is not enough cold for the entire volume.
Is it possible to operate the refrigerator if the upper chamber does not freeze?
For a short time - yes, if you put perishable foods in the freezer. However, prolonged operation in this mode is harmful to the compressor, which will work non-stop, trying to gain temperature. This can lead to overheating and burning.
How long should the temperature be restored after defrosting?
Usually the refrigerator takes from 2 to 6 hours to reach operating temperature after complete defrosting and turning on. If more than 8 hours have passed and it is still warm in the upper chamber, then there is a technical malfunction.
Why did the refrigerator start working after defrosting, but a week later it stopped again?
This is a sure sign of a malfunction of the defrost system in No Frost models. Ice has again blocked the evaporator or air passages. The heating element, defrost sensor or timer needs to be replaced.
Does the amount of food in the chamber affect cooling?
Yes, but indirectly. An empty refrigerator loses cold faster when the door is opened. However, if there are too many products and they tightly clog the shelves, blocking the holes for air circulation (especially in No Frost), the cold will not be distributed evenly, and the upper part will become warmer.