The situation when you open the refrigerator and find that there is ice and food frozen in the freezer compartment, and heat in the upper compartment or room temperature reigns, is one of the most common and alarming. This is a classic symptom of poor refrigerant circulation or a control system failure. Many users mistakenly believe that if the compressor is humming, it means the equipment is working properly, however, for full operation of two-chamber models, synchronization of all components is necessary.
In modern systems No Frost and classic models with drip defrosting, the reasons may be radically different. If you ignore the first signs, such as melted ice cream bars or condensation on the walls of the main chamber, you may encounter complete spoilage of the food. In this material, we will analyze in detail the mechanical and electrical causes of the malfunction so that you can understand the scale of the problem.
The first thing you need to do before calling a technician is to conduct an initial diagnosis. Often the problem lies not in a complex breakdown, but in a banal violation of operating rules or reset settings. However, if simple methods do not help, there may be serious damage to the circuit or failure of the compressor.
Symptoms and initial diagnosis of the problem
Before looking for the answer to the question of what exactly is broken, it is necessary to accurately determine the nature of the malfunction. Listen carefully to the operation of the unit: does the motor-compressor work constantly without stopping or, conversely, is silent? In models with one compressor and one cooling circuit, the cold from the freezer must be transferred to the upper chamber through special channels. If this does not happen, it means freon circulation the freon circulation is broken.
Pay attention to the temperature of the walls inside the refrigerator compartment. If they are dry and warm, while there is ice in the freezer, this indicates that the refrigerant is either not reaching the top, or its pressure has dropped critically low. It is also worth checking whether the emergency temperature indicator on the control panel is on, which often flashes red.
⚠️ Attention: If you notice swelling in the back wall of the refrigerator or a characteristic smell of chemicals, immediately unplug the appliance. This may indicate a leak of flammable refrigerant, which creates a risk of ignition.
To accurately understand the state of the equipment, it is important to distinguish models by type of control. In mechanical systems, the thermostat is responsible for regulation, while in electronic models (with a display), the control unit and sensors are responsible for the distribution of cold. A malfunction of one element in a complex circuit can cause upper chamber to stop cooling, even if the compressor is working properly.
Perform a simple test: defrost the refrigerator completely within 24 hours, unplugging it from the outlet. If, after turning it on, it starts to freeze normally in both compartments, but after a few days the problem returns, it means that there is ice plug a blockage in the system or a blockage in the capillary tube.
Refrigerant leak: the most common cause
The most likely reason why the freezer in the refrigerator works, but the top does not, is a banal freon leak. In dual-circuit systems, or models with one circuit but not enough gas, there is simply not enough refrigerant to cool the entire volume. The gas circulates in a circle: first it passes through the freezer, giving off some of the cold, and then it must go to the upper compartment. If there is little gas, there is not enough gas for the second stage.
Leaks often occur in places where pipes are soldered or due to corrosion of the evaporator, especially if you used sharp objects to chip the ice. It is difficult to visually notice a leak, since freon is colorless and odorless (although some modern types have a characteristic odor added by the manufacturer for safety). An indirect sign is a black coating on the compressor tubes or swelling of the inner wall.
If this occurs depressurization of the circuit, the compressor will work almost non-stop, trying to reach the set temperature, but to no avail. This leads to overheating of the motor and increased energy consumption. In such a situation, operation of the equipment is impossible without the intervention of a specialist.
Is it possible to refuel the refrigerator yourself?
Refilling it yourself with freon is extremely difficult and dangerous. Requires evacuation of the system, precise knowledge of the type of refrigerant and its quantity, as well as special equipment. An attempt to refuel “by eye” will lead to compressor failure.
It is important to understand that you cannot simply add gas to the system. It is necessary to find the leak, solder it and only then refill it. If this is not done, the new freon will also evaporate after a short time. Therefore, if a leak is suspected, calling a technician with a leak detector is mandatory.
Malfunctions of the thermostat and temperature sensors
In mechanically controlled refrigerators, the thermostat (thermostat) is responsible for turning the compressor on and off. This device measures the temperature in the evaporator or inside the chamber and closes or opens an electrical circuit. If the thermostat contacts are “stuck” in the open position, the compressor simply will not receive a signal to start, and the cold will stop being generated.
In models with electronic control (No Frost), the role of the thermostat is performed temperature sensors (NTC thermistors). They transmit data to the main control module. If the sensor in the refrigerator compartment “lies” and shows that it is already -5°C, although in fact it is +15°C, the module will not give the command to cool. As a result, the freezer can work according to its schedule, and the top will remain warm.
Often the problem lies in oxidation of the contacts or a break in the wiring going to the sensor. Vibration during compressor operation over time leads to chafing of wires or failure of soldering. Diagnostics in this case requires checking the circuit with a multimeter.
A symptom of a thermostat malfunction can also be a situation when the refrigerator does not turn on at all, or, conversely, works without breaks, freezing all food in the upper compartment in ice. Adjusting the thermostat knob in such cases does not have any effect.
Problems with the defrosting system (for No Frost)
If you have a refrigerator system No Frostthen the lack of cold in the upper compartment when the freezer is running often indicates a failure in the automatic defrosting system. In such models, cold air is forced by a fan from the freezer into the refrigerator through special air ducts. If these air ducts become clogged with ice, circulation stops.
Three main elements are responsible for the defrosting process: a heating element (heater), a defrost sensor and a timer (or electronic module). If the heating element burns out or the timer is stuck in cooling mode, the ice does not melt, but grows. Sooner or later, it will block the air supply channels, and the cold will stop flowing into the upper chamber.
Signs of such a malfunction are:
- ❄️ Severe freezing of the back wall in the freezer.
- 🔊 Lack of characteristic sound of the fan.
- 💧 The appearance of a puddle of water under the refrigerator (the ice melts and flows out without having time to evaporate).
In some cases, ice can block the damper itself that regulates the air flow. This mechanical obstacle prevents the cold flow from penetrating into the main volume. Defrosting for a day often helps to temporarily solve the problem, but without replacing the faulty element of the defrosting system, the ice will build up again.
Clogged capillary tube and ice plug
Another technical reason why the freezer works, but the top does not, is a clog in the capillary tube. This is a very thin tube in which throttling (a sharp drop in pressure) of freon occurs. If there is moisture or oil breakdown products in the system, they can freeze and clog the lumen.
The formed ice plug passes freon only into the freezer chamber, where the pressure is higher, but blocks its further movement into the evaporator of the refrigeration compartment. A characteristic sign is that the condenser (grid at the back) is heated only partially, and not over the entire area.
To eliminate this problem you need:
- 🛠️ Blowing the circuit with nitrogen under high pressure.
- 🔄 Replacing the filter-drier that retains moisture.
- 💉 In some cases, replacing the capillary tube itself.
This work cannot be done at home without specialized equipment. Independent attempts at cleaning can lead to rupture of tubes or damage to the compressor.
☑️ Symptoms of capillary blockage
Compressor malfunctions
Although the compressor is the “heart” refrigerator, its breakdown does not always mean complete silence. There is a concept called "turn-to-turn short circuit" or loss of performance. In this case, the motor hums and starts, but does not create enough pressure to pump freon through the entire circuit.