The situation when the refrigerator stops freezing in the upper compartment, but in the lower compartment, on the contrary, everything freezes or the temperature remains normal, is one of the most common and frightening for the owner of household appliances. Temperature violation in the freezer compartment jeopardizes the safety of food, requiring immediate intervention. Users often mistakenly believe that the problem lies in the compressor, but statistics from service centers tell a different story: most often the defrost system or refrigerant leak is to blame.
In two-chamber models with the No Frost system, cold air is forced from the freezer into the refrigerator compartment through special channels. If this flow is blocked by ice or the fan stops working, the top chamber stops cooling. In models with a weeping system (drip), a violation of freon circulation or a breakdown of the thermostat also leads to the fact that evaporator does not reach the desired temperature. It is important not to panic, but to consistently check the symptoms before calling a technician.
Further actions depend on how long ago you noticed the problem and how the device behaved before. Is the engine humming? Can you hear the sound of the fan running? Has there been any extraneous noise or, conversely, has there been suspicious silence? Answers to these questions will help you narrow down the troubleshooting and understand whether complex repairs with replacement of parts are required or simple defrosting is sufficient.
Primary diagnostics and visual inspection
Before disassembling the unit, it is necessary to carry out basic diagnostics. Often the reason that the upper chamber does not work is trivial: violation of operating rules. Check whether it fits snugly sealing rubber on the door. If it is dirty, damaged, or simply not completely closed, warm air enters the chamber, which the cooling system does not have time to remove.
Pay attention to the temperature indicators, if there are any on the case. In some models electronic control module it can signal a specific error by flashing lights. It is also worth listening to the operation of the compressor: if it works without stopping, this is a sure sign that the temperature in the chamber does not reach the set values, and the automation is trying to compensate for the loss of cold.
⚠️ Attention! If you notice that the back wall of the refrigerator compartment is completely covered with a thick layer of ice or a “coat”, and the food on top is not cooling, this is a classic sign of a broken defrost cycle. Do not try to chip the ice with a knife - this may lead to a breakdown of the circuit.
The visual inspection also includes checking the internal space for obstructing objects. Sometimes food lying close to the back wall blocks the outlets of the cold air supply channels. In this case, the circulation is disrupted, and the cold simply does not reach the upper shelves.
Problems with the defrost system (No Frost)
In refrigerators with a No Frost system, the main reason for the lack of cold in the upper compartment is a malfunction of the automatic defrosting system. Defrost heating element, temperature sensor (defroster) and timer (or electronic module) must operate in a strict loop. If one of the elements fails, the evaporator located behind the rear panel of the freezer becomes overgrown with ice.
Ice blocks the operation of the fan, which drives cold air into the refrigerator compartment. As a result, the fan either stops due to freezing of the blades, or simply spins the air inside the freezer without letting it flow to the top. Diagnosis of this problem requires removing the back panel in the freezer compartment to visually assess the amount of ice on the evaporator.
The defrost sensoritself often fails, which stops sending a signal to turn on the heater, or the heating element burns out. In models with a mechanical timer, the mode switching mechanism itself may jam. In such cases, the refrigerator operates in freezing mode constantly, accumulating ice, but not switching to defrosting mode.
☑️ Diagnostics of the No Frost system
To replace elements of the defrost system, it is often necessary to completely defrost the refrigerator within 24 hours. This is necessary to remove all the ice from hard-to-reach channels, otherwise the new part may quickly fail or the problem will persist.
Refrigerant leakage and problems with the compressor
If the defrost system is working properly, but there is no cold, there is a high probability of a freon leak. Refrigerant circulates in a closed circuit, and when If its tightness is broken, the pressure drops. In two-chamber refrigerators, this often manifests itself specifically: first, the upper chamber (or freezer, depending on the design) stops freezing, and then the temperature in the main compartment also rises.
If freon leaks, the compressor may work longer than usual or turn on for short periods of time with long pauses, trying to gain temperature. The condenser (the grill at the back or the sides) may feel lukewarm or cold to the touch when it should normally be hot. Also a sign of a leak is swelling of the inner wall of the refrigerator in the place of the foamed evaporator.
| Symptom | Probable cause | Action |
|---|---|---|
| Compressor is hot, condenser is cold | Freon leak or capillary blockage | Call a technician to find a leak |
| The compressor does not turn on | Faulty start relay or thermostat | Checking the electrical circuit |
| A gurgling sound is heard | Residual freon in the system | Evacuation and refilling required |
| The engine hums, but does not start | Compressor jammed | Replacing the compressor |
It is impossible to fix the leak and refill the refrigerator yourself freon without special equipment (vacuum pump, pressure gauge station, scales). Attempts to simply “add gas” without searching and soldering the leak will only lead to a temporary effect and damage to the compressor.
Why can’t you ignore the operation of the compressor without stopping?
If the compressor works without interruptions, trying to gain temperature when freon leaks, it overheats. The oil in the compressor loses its properties, the valves become coked, and as a result, the expensive motor-compressor fails, requiring replacement of the entire unit.
Malfunctions of the thermostat and electronic module
In refrigerators with electromechanical control, the thermostat (thermostat) is responsible for turning the compressor on and off. This device measures the temperature in the evaporator or chamber. If the thermostat contacts burn out or the bellows tube loses sensitivity, the signal to turn on the compressor is not received and no cold is produced.
In models with electronic control (No Frost with display), the functions of the thermostat are performed by the temperature sensor, and the logic controls control module. Failure of the AIR (air) sensor or evaporator sensor can lead to the fact that the “brains” of the refrigerator will “think” that the temperature is normal and will not turn on the cooling.
Diagnostics of the thermostat in mechanical models is often carried out by elimination or direct replacement. To check, you need to close the contacts with wires: if the refrigerator starts working, it means the thermostat is faulty. In electronic models, it is necessary to test the sensors with a multimeter and check their resistance with the table of ratings for a specific model.
⚠️ Attention! When replacing a thermostat or sensors, it is important to correctly install the capillary tube or the sensor itself in the seat. Loose contact will result in incorrect temperature readings and improper operation of the refrigerator.
Freezing of air supply channels
A separate category of problems, typical for some refrigerator models (for example, certain series Indesit, Atlant or Beko), is the freezing of the transition channel between freezer and refrigerator compartments. Even if the No Frost system is working properly, moisture from food can condense in this narrow channel and turn into an ice plug.
As a result, cold air physically cannot penetrate into the upper compartment. Visually, this is manifested by the fact that everything in the freezer is frozen, but everything in the refrigerator is warm. Sometimes the plug can be seen by looking into the channel hole on the back wall of the refrigerator compartment.
To eliminate this problem, completely defrosting the refrigerator for 24 hours with the doors open is often sufficient. However, if the duct design requires a heater or damper, these should also be checked. In some cases, it is necessary to dismantle the internal panel of the refrigerator compartment to clean the channel.
Damage to the seal and loss of tightness
It would seem that a simple element - sealing rubber band - plays a critical role. If it does not fit tightly, warm, moist air constantly enters the chamber. The cooling system tries to cool it, which is why an increased amount of ice accumulates on the walls and the evaporator, which ultimately blocks the operation of the system.
You can check the tightness using a sheet of paper: clamp the sheet with the door around the perimeter. If the sheet is pulled out without effort or with jerks in different places, it means that the seal requires replacement or adjustment. Also, the elastic can become deformed over time, crack, or become contaminated with fat, which reduces its elasticity.
A temporary solution can be to heat the seal with a hairdryer (carefully, without overheating) to restore elasticity or to place a seal in places where there is a loose fit. However, if the rubber band is torn or severely deformed, the only help is replacing the seal a new one.
Frequently asked questions and answers (FAQ)
How long does it take to defrost a refrigerator if it does not freeze on top?
To completely defrost and thaw ice in hidden channels and on the evaporator, it is recommended to leave the refrigerator turned off with the doors open for at least 24 hours. A shorter defrosting may not completely eliminate the ice jam.
Is it possible to use the refrigerator if the upper chamber does not work?
You can use the refrigerator only temporarily if the lower chamber (freezer) is working normally. However, food in the upper compartment will quickly spoil. Long-term operation in this mode can lead to compressor failure due to increased load.
Why is it warm in the refrigerator compartment, but everything is frozen in the freezer?
This is a classic sign of a malfunction of the defrost system (the evaporator is clogged with ice) or a freon leak. In the first case, the fan does not drive air, in the second, there is only enough freon for the first circuit of the evaporator, it does not reach the second.
How to understand that the compressor has burned out?
If the compressor hums, tries to start, clicks and turns off, or it is hot, but absolutely silent and cold (does not vibrate), most likely it faulty The technician will make an accurate diagnosis after measuring the resistance of the windings.