The situation when the refrigerator stops efficiently cooling food in the upper chamber is one of the most common and alarming for owners of household appliances. If you notice that top shelf has become warm, and food has begun to deteriorate faster than usual, this is a direct signal that the refrigerant circulation is disrupted or the defrosting system is malfunctioning. Ignoring the first symptoms can lead to a complete stop of the compressor, the repair of which will cost much more.
Before calling a technician, it is worth carrying out an initial diagnosis, since in 30% of cases the problem lies not in a breakdown of the unit, but in operating errors or improper installation. Modern models refrigerators, such as Indesit, LG or Atlant, are equipped with complex electronics that can block the start of the compressor at the slightest deviation in temperature. Understanding the principles of operation of your equipment will help save time and money.
In this article we will look in detail at why the upper chamber stops freezing, how to independently identify the malfunction and what steps to take to restore the functionality of the device. You will learn about the critical components of the system No Frost, features of the thermostat operation and signs of freon leakage. A competent approach to diagnostics will allow you to make the right decision on further actions.
Violation of operating rules and initial check
The most common, but common reason for the lack of cold from above is a banal violation of the rules for loading the chamber. If you tightly fill the top shelf with food, blocking access to cold air, then natural convection is disrupted. Cold air simply cannot sink down or be distributed evenly, creating “heat pockets” in the upper part. ventilation holes, then natural convection is disrupted. Cold air simply cannot sink down or distribute evenly, creating “heat pockets” at the top.
It is also worth checking whether you have just put hot food into the chamber. Evaporation of moisture and heat from the pan can throw off the sensor settings, causing thermostat to work idle. In some models, this causes a temporary failure, after which the system returns to normal, but it is better not to take risks.
⚠️ Attention: Never put hot or warm food in a running refrigerator. This creates a colossal load on the compressor and leads to the formation of an ice coat on the evaporator, which blocks air circulation.
Pay attention to the position of the refrigerator itself. If it is too close to the wall or cabinet sides, heat dissipation from the condenser is impaired. Overheating of the rear grille can cause the unit to wear out but not produce the desired temperature. Check the gap between the back wall and the furniture - it should be at least 5-7 cm.
The first step should always be complete defrosting. Even if you have a No Frostsystem installed, ice may have accumulated in the hidden channels of the air ducts. Unplug the appliance for 12–24 hours, leaving the doors open. This will help melt the ice plugs, which are often the reason why upper chamber stops cooling.
Malfunctions of the No Frost and airflow system
If after defrosting the problem returned after a couple of days, then the problem is in the mechanical or electrical part of the system automatic defrost. In refrigerators, cold is generated in the freezer compartment and then supplied by a fan to the refrigerator compartment. If this process is disrupted, the upper part (where the refrigerator compartment is usually located) stops receiving cold. No Frost The cold is generated in the freezer compartment and then blown into the refrigerator compartment by a fan. If this process is disrupted, the upper part (where the refrigerator compartment is usually located) stops receiving cold.
One of the main reasons is failure blowing fan. If the impeller does not rotate, cold air remains in the freezer, and there is stuffiness on top. You can check this by listening to the operation of the unit: there should be no characteristic noise of a working fan if it is broken.
- 🔌 Open circuit of the power supply: Check whether voltage is supplied to the fan motor; the contacts may have oxidized.
- ❄️ Freezing of the blades: The fan may jam due to ice if the defrosting system does not work correctly.
- ⚙️ Wear of the bearings: Over time, the motor shaft may become warped, which will lead to a stop of rotation.
The second important element is Defrosting heating element (heating element). Its task is to periodically melt the frost on the evaporator. If the heating element burns out, the evaporator becomes overgrown with ice, the channels are blocked, and the air stops circulating. It is difficult to notice visually; disassembly of the rear panel of the freezer is required.
How to check the defrosting heating element with a multimeter?
To check, you need to call the heating element with a multimeter in resistance measurement mode. The normal resistance of a working heating element is usually from 200 to 600 Ohms. If the device shows infinity (open circuit) or zero (short circuit), the element must be replaced.
The third component that often fails is defrost sensor (defrost timer or thermostat). He gives the command to turn on the heating element. If the sensor is “stuck” in the “cold” position, the heating will never turn on, and the ice ball will grow to a critical size, completely blocking the air channel.
Problems with the thermostat and temperature sensors
In classic two-chamber refrigerators (where there is no No Frost) for maintaining temperature answers thermostat. This is a mechanical or electronic device that reads the temperature in the chamber and turns the compressor on/off. If the thermostat is faulty, it may “think” that the chamber is already cold and not start the engine, although in fact it is warm there.
Often the problem lies in the capillary tube thermostat itself, which could have become dislodged or lost contact with the evaporator. In this case, the sensor reads the temperature incorrectly. In electronic models, they are responsible for this sensors, which can provide erroneous data to the control board.
| Symptom | Possible cause | Check method |
|---|---|---|
| The refrigerator does not turn on | The thermostat is faulty (open circuit) | Close the thermostat contacts directly |
| Works without stopping | Thermoregulator is “stuck” when turned on | Temperature measurement in the chamber (will be below normal) |
| Periodic failures | Oxidation of contacts or broken wiring | Visual inspection and “ringing” of the chain |
If you have a two-compressor unit, then a separate motor is responsible for the upper chamber. If it does not start, but the light in the chamber is on, then the problem may be in the start relay or the windings of the compressor itself. In such cases, a click is often heard, followed by silence or a buzzing sound that turns off.
Refrigerant leakage and problems with the compressor
The most unpleasant reason why the upper part does not freeze is freon leak. The refrigerant circulates in a closed loop: first it passes through the freezer compartment (where the temperature is lowest) and then through the refrigerator compartment. If there is not enough gas in the system, it is only enough to cool the first section of the circuit (the freezer), and it simply does not reach the top.
Signs of a freon leak are quite typical. The compressor can work almost non-stop, trying to gain temperature, but there is no effect. At the same time condenser (the grill at the back) may be barely warm or cold, although normally it should be hot. Swelling of the side walls of the refrigerator may also be observed.
⚠️ Attention: Self-filling the refrigerator with freon is prohibited and dangerous. This requires special equipment, evacuation of the system and precise knowledge of the type of refrigerant (R134a, R600a). An attempt to refuel “by eye” will lead to compressor failure.
Another reason is clogged capillary tube. An ice or oil blockage may have formed in the system, which physically prevents refrigerant from entering the upper part of the circuit. This is often accompanied by a whistling sound in the area of the filter drier. This can only be treated by purging the system with nitrogen and replacing the filter by a technician.
If the compressor hums, clicks, but does not start, the starting relay may have burned out or an interturn short circuit in the motor windings. In this case, the upper chamber will also remain warm, since refrigerant circulation does not occur at all.
Failures in the operation of the electronics and control module
Modern refrigerators, such as Bosch, Siemens or Samsungare controlled by an electronic module. This is the “brain” of the device, which receives signals from sensors and controls the compressor, fans and heating elements. If moisture gets on the board (for example, when washing the floor or defrosting) or a power surge occurs, it could fail.
Symptoms of a control module failure are varied: the refrigerator may turn on and off randomly, blink indicators, make beeps, or simply not respond to buttons. Often in such cases, the upper chamber does not freeze because the board “does not see” the cooling command or does not supply voltage to the corresponding node.
- 💡 Burnt elements: On the board, capacitors may swell or burn out tracks.
- 🌊 Oxidation of contacts: Moisture causes corrosion of connectors, disrupting transmission signals.
- 🔄 Software failure: Rarely, but there is a software failure that requires flashing the module.
☑️ Electronics diagnostics
Diagnostics of electronics requires special knowledge and tools. If you are not confident in your abilities, it is better to contact the service. Replacing a module is an expensive procedure, but often necessary to restore the functionality of the equipment.
When you need to call a technician: critical situations
Despite the desire to save money, there are situations when independent repairs can lead to permanent breakdown of the device. If you have defrosted, checked the tightness of the door closure and the position of the thermostat, but the cold did not appear, most likely there is a technical problem.
It is especially dangerous to ignore signs of a refrigerant leak or problems with the compressor. Running the engine without enough coolant or oil will cause it to overheat and seize. Repair in this case will cost 2-3 times more than a timely call to a specialist.
It is also worth calling a technician if you hear unusual sounds: loud knocking, grinding, hissing or whistling noise. These sounds indicate mechanical problems inside the unit that cannot be solved without disassembly and special tools.
Is it possible to temporarily use a refrigerator if it does not freeze on top?
It is absolutely forbidden to use a refrigerator with a faulty upper chamber to store perishable foods (meat, milk, fish) - you risk getting food poisoning. You can temporarily store vegetables, fruits, unopened canned food or drinks that do not require strict temperature conditions there. However, it is not recommended to operate the equipment in this mode for a long time, since the compressor is overloaded.
Why does only the freezer freeze in a two-chamber refrigerator?
This is a classic symptom of a freon leak or a clogged capillary system. The refrigerant does not reach the refrigeration chamber circuit. Also, the reason may be a malfunction of the damper (in the No Frost system), which blocks the supply of cold air from the freezer upwards.
How long should defrosting last to remove the ice plug?
For the ice to completely melt in the hidden channels of the air ducts and on the evaporator, the refrigerator must stand unplugged from the network with the doors open for at least 12 hours, or better yet, a full 24 hours. Using a hairdryer or boiling water to speed up the process is prohibited, as this can damage the plastic and seals.
What should you do if, after defrosting, the refrigerator started working, but after 3 days it stopped again?
This means that the automatic defrosting system (heating element, timer, sensor) is not working. Ice accumulated again and blocked the channels. It is necessary to call a technician to diagnose and replace faulty elements of the No Frost system.