The situation when the upper chamber of the refrigerator stops cooling food, while the freezer continues to freeze “like a beast,” is one of the most common and at the same time confusing problems. Users are often at a loss, believing that if the equipment makes sounds and freezes at least partially, then “everything is fine” with it or, conversely, that it is completely broken. In fact, such a scenario indicates specific malfunctions in the refrigerant circulation system or temperature control.
In most modern models, especially those equipped with the system No Frost, food is cooled not due to a separate evaporator in each chamber, but due to the forced injection of cold air from the freezer. If this process is disrupted - the damper is closed, the fan is stopped or the channel is clogged with ice - the upper chamber turns into a regular cabinet. Understanding the physics of the process allows you not to panic and carry out initial diagnostics yourself before calling a technician.
It is important to note that ignoring primary symptoms can lead to damage to a large number of products and complicate repairs. Modern double-circuit systems they require careful attention, since the failure of one automation element blocks the operation of the entire unit. In this article we will analyze in detail the mechanical, electrical and operational causes of the malfunction.
The principle of operation of the No Frost system and cold distribution
To understand why the cold disappeared in the main chamber, it is necessary to briefly consider the design of a typical of a refrigerator with a No Frost system. In such units, the evaporator, where freon boils and takes away heat, is located hidden, usually in the back wall of the freezer. Cold air is forced by a special fan through the air ducts into the refrigerator compartment.
If the freezer is working properly, this means that the compressor, condenser and the evaporator itself are functioning normally. The problem is localized in the cold “delivery” zone. The key elements here are temperature regulator damper and the circulation fan. The damper opens at the command of the thermostat, letting in cold air, and closes when the temperature is reached.
⚠️ Attention: If you hear that the fan is humming, but no air is flowing, or, conversely, there is silence, do not try to disassemble the back panel of the camera without defrosting. There may be an ice plug inside, which, due to mechanical impact, will damage the plastic or heater.
In models with one compressor and one refrigerant circuit (the so-called Full No Frost or combined system), imbalance is often associated with loss of tightness or blockage capillary tube, but in the case of a working freezer, it is often the air flow mechanics that are to blame.
Freezing of the air supply duct and ice plug
One of the most common reasons why the refrigerator does not cool is the banal freezing of the air duct. This occurs when the evaporator defrost system fails. Normally Defrost heating element turns on periodically, melting the ice on the evaporator, and water flows into the drain. If the heating element is burned out, the defrost temperature sensor is “lying” or the timer is jammed, ice builds up.
Sooner or later, the ice blocks the channel through which cold air should flow into the upper chamber. As a result, the fan circulates air inside the freezer, but the cold does not reach the food in the refrigerator. Visually, this can manifest itself as a “fur coat” on the back wall of the freezer or, conversely, a completely dry surface in the absence of cold.
To diagnose this condition, complete defrosting of the unit is often required. It is necessary to unplug the refrigerator and leave it with the doors open for at least 24 hours. This time is needed for the ice plug in the hidden channels to completely melt.
- 🧊 Sympath 1: After defrosting, the refrigerator started working normally, but after 1-2 weeks the situation repeated itself (indicates a breakdown of the defrosting system).
- 🔇 Symptom 2: The fan operates intermittently or makes a grinding noise (the blades could have touched frozen ice).
- ❄️ Symptom 3: On the back wall of the refrigerator compartment, drops of water are visible or, conversely, a dry “coat” in one corner.
If the equipment started working after defrosting, but the problem soon returned, it means that the components of the defrosting system need to be replaced: Heating element, defrost sensor or timer. Operating the refrigerator in constant “wear and tear” mode without defrosting cycles will lead to failure of the compressor.
☑️ Actions if you suspect an ice block
Faulty temperature control damper (Damper)
A damper (or damper) is a mechanical or electronic “door” that meters the amount of cold air flowing from the freezer into the refrigerator compartment. It is controlled by an electronic module based on the readings of temperature sensors. If the damper is stuck in the closed position, the cold simply does not reach the products.
In electronic models, the damper is a servo drive with plastic gears. Over time, the lubricant dries out, or the gears break, and the mechanism stops responding to commands. In simpler models, the damper can be controlled by a thermosyphon, which also tends to fail.
You can check the operation of the damper by listening to the characteristic click when changing the temperature settings in the menu (if there is one) or when turning it on for the first time. If you hear the hum of the damper motor, but the damper itself does not move, it means that the mechanical part is damaged.
⚠️ Attention: Do not try to forcefully open the damper with your finger or a screwdriver. At low temperatures, plastic becomes brittle and breaks easily, and repairing the drive will cost more than replacing the entire assembly.
Often the cause of jamming is condensation, which freezes in the damper mechanism. This is especially true for models where the door seal is already worn out and allows warm, moist air to pass through, settling in the damper area.
Problems with the evaporator fan
The fan is the “heart” of the air circulation system in No Frost refrigerators. It is he who drives air masses through the evaporator and further along the channels. If the fan stops, cold heavy air remains at the bottom of the freezer and does not rise into the upper chamber.
The reasons for the fan stopping can be different:
- 🔌 Open circuit: The wires going to the fan motor are broken (often frayed at the bend of the door).
- 🛑 Mechanical stop: The blades rested on frozen ice (see the section about the ice plug).
- ⚙️ Wear bearings: The fan bushings are worn out, the shaft is skewed, the motor hums, but does not spin or barely spins.
Diagnostics is simple: open the freezer (in some models you need to remove the plastic panel). When the freezer door is open, the fan should often stop (the door switch is triggered), but if you press the limit switch to simulate a closed door, the fan should start. If you can hear the sound of the compressor running, but the fan is silent, the problem is in it or in the control board.
Is it possible to temporarily operate a refrigerator with a non-working fan?
Theoretically, it is possible, but the cooling efficiency of the refrigeration chamber will drop to zero. Food in the freezer will freeze unevenly, and food in the upper compartment will begin to spoil. Long-term operation without air circulation can lead to overheating of the compressor, since heat exchange is impaired.
Reduced compressor performance and freon leakage
Although the question was about the situation when “the freezer is working,” it is important to understand the nuance: it can work worse than usual, but the user does not notice it until it deteriorates products in the upper chamber. If a micro-leakage occurs in the system refrigerant (freon) or the compressor has lost compression, the pressure is not enough to “break through” the entire circuit.
In two-chamber refrigerators with one compressor, the refrigerant first passes through the freezer chamber (where temperature is the lowest), and then through the refrigeration room. If there is a shortage of freon, it simply does not reach the second evaporator or the capillary of the upper chamber. As a result, the freezer is -10°C (instead of -18°C), and the refrigerator is +15°C.
Signs of a leak or loss of performance:
- 🌡️ Temperature mode: The freezer is freezing, but the food there is soft, not “stone-like.”
- ⏱️ Operating mode: The compressor works almost non-stop (around the clock), trying to gain temperature.
- 🔥 Heating condenser: The rear grill is hot only at the beginning (1/3 of the length) or, conversely, completely cold.
Unlike problems with ventilation, a freon leak cannot be eliminated on your own. You need to call a technician with equipment to find leaks, evacuate the system and charge it with new refrigerant.
Comparative table of symptoms and causes
For ease of diagnosis, we will summarize the main symptoms in a single table. This will help you quickly navigate the nature of the malfunction of your unit.
| Symptom | Probable cause | Difficulty of repair | Necessary actions |
|---|---|---|---|
| The freezer is working, but The refrigerator is warm, there is no ice | The damper (damper) is faulty | Medium | Replacing the damper |
| A hum is heard, there is no cold, there is ice on the walls | Frozen air supply channel | Low (defrost) | Defrost 24 hours, check the heating element |
| The compressor is humming, but there is no cold anywhere | Freon leak / Blockage | High | Call a technician |
| Fan does not spin, silence | Fan or door sensor burnt out | Medium | Replacing the fan |
| The refrigerator turns on and immediately turns off | Faulty starting relay | Low | Replacing the relay |
Analysis The table shows that more than 50% of cases when the freezer works, but the refrigerator does not, are associated with air circulation problems (ice, fan, damper), and not with a serious hardware breakdown.
⚠️ Attention: The repair difficulties indicated in the table are arbitrary. Replacing the compressor on your own or searching for a freon leak without professional equipment and skills is strictly not recommended and can lead to final breakdown of the unit.
Frequently asked questions (FAQ)
Why did the refrigerator start working after defrosting, but then stopped again a week later?
This is a classic sign of a malfunction of the automatic defrosting system. Most likely, the sensor that controls the temperature of the evaporator has burned out or failed. Ice accumulates again and blocks the channel. Diagnostics with a multimeter and replacement of the burnt element are required. Defrosting heating element or the sensor that controls the evaporator temperature has failed. Ice accumulates again and blocks the channel. Diagnostics with a multimeter and replacement of the burnt element are required.
Is it possible to use the refrigerator if the upper chamber does not work?
For a short time - yes, if you put the food in the freezer. However, prolonged operation in this mode is harmful to the compressor, since the thermal balance is disturbed. In addition, bacteria multiply in a warm chamber, which can lead to the appearance of an unpleasant odor, which is then difficult to remove from the entire system.
How to check whether the damper is working without disassembling the refrigerator?
It is impossible to completely check without disassembling it. However, you can indirectly judge by the sound: if there is a sharp change in the set temperature (for example, from +5 to +1), after 1-2 minutes a quiet click or buzzing of the damper servomotor should be heard. If there are no sounds at all, perhaps the damper does not receive a signal or is jammed.
Does the position of the refrigerator affect this problem?
Yes. If the refrigerator is tilted forward, the door may not close completely (even if it visually appears to be closed). This leads to a constant flow of warm air, freezing of the channels and stopping the supply of cold. Check the level of inclination and, if necessary, tighten the front legs.
What to do if the compressor is hot but there is no cold?
A hot compressor in the absence of cold (or weak cold) often indicates that it is running “idle” due to a freon leak or blockage in the system. This may also be a sign of a malfunction of the motor itself. In this case, you need to disconnect the device from the network and call a specialist.