Situation, when freezer compartment continues to properly freeze food, while the main compartment is warm, this is a classic scenario for the breakdown of modern refrigeration equipment. The owner of the equipment is faced with a paradox: the compressor is humming, the freezer is working, but in the upper compartment the temperature rises above the permissible values. This is not just discomfort, it is a direct threat to the safety of fresh food, meat and dairy products.
The reasons for this imbalance lie in the features refrigerant circulation and operation of the defrost system. Unlike older models, where the cold was distributed differently, modern units use complex temperature control algorithms. If you notice that the refrigerator does not freeze, but the freezer is functioning, this indicates that the problem is local in nature or is associated with a violation of heat exchange, and not with a complete loss of freon.
Ignoring the first symptoms can lead to failure of an expensive compressor or complete replacement of the heat exchanger. In this material, we will analyze in detail the technical aspects of the operation of refrigeration systems, list the most likely malfunctions and suggest what steps need to be taken for diagnosis. Understanding the operating principles of No Frost or Static Cooling will help you quickly identify the source of the problem.
⚠️ Attention: If you hear a sharp click followed by silence, or, conversely, the motor hums continuously without stopping, immediately turn off the device from the network. Prolonged operation in emergency mode can lead to a fire in the wiring or the wedge of the piston group.
Principles of cold distribution in modern systems
To understand the nature of the malfunction, it is necessary to briefly consider how the cooling system is designed. In most modern models, cold is generated precisely in the evaporator area, which is most often located in the freezer compartment or behind the rear wall of the upper compartment. Fan pumps cold air through special channels into the refrigerator compartment. If this process is disrupted, a temperature imbalance occurs.
In systems No Frost the circulation of air masses plays a key role. The air passes through the evaporator, is cooled and supplied to the chamber. If the vents are clogged or the fan fails, the cold simply does not reach the main compartment. In static systems (Direct Cool), the refrigerant passes through tubes hidden in the walls, and a violation of the tightness of the circuit or a clogged capillary tube leads to the fact that the freon boils only at the beginning of the circuit (in the freezer), without reaching the refrigeration compartment.
It is important to distinguish between types of temperature control. In two-compressor models, each compartment is responsible for its own independent unit. If you have exactly this type of equipment, then the problem most likely lies in the thermostat or start relay of a specific refrigerator compressor. In single-compressor models, which are more common, one motor serves both circuits, and a malfunction in the distribution of refrigerant affects both compartments, but manifests itself in different ways.
Malfunctions of the defrost system and freezing of the evaporator
One of the most common reasons why the refrigerator has stopped freezing when working freezer, there is a malfunction of the defrost system. In units with technology No Frost, ice inevitably forms on the evaporator. Periodically it must thaw thanks to the heating element (heating element). If this process does not start, the ice coat grows and tightly blocks the ventilation ducts.
As a result, the fan continues to circulate air, but it cannot pass through the ice plug to the shelves of the refrigerator compartment. The user hears the motor running, sees frost in the freezer, but the main chamber is warm. Over time, ice can block the fan itself, resulting in a characteristic hum or crackling sound. Diagnosis of this problem often requires partial disassembly of the rear panel of the freezer.
The main elements of the defrost system that fail include:
- 🔥 defrost heating element — the heater coil burns out and the ice stops melting.
- 💧 Defrost sensor - incorrectly reads the temperature and does not give a command to turn on the heating.
- ⏱️ Timer or electronic module - "forgets" to start the defrost cycle at the right time.
- 🌡️ Thermal fuse - burns out when overheated, breaking the circuit power supply to the heating element.
To temporarily solve the problem, it is often recommended to completely defrost the refrigerator. To do this, you need to disconnect the device from the power supply, empty the chambers of food and leave the doors open for at least 24 hours. Only long-term defrosting will allow the ice in the hidden channels to completely melt and drain.
⚠️ Attention: Do not try to speed up the defrosting process by using a hairdryer, hot water or an ice knife. Mechanical damage to the plastic panels or evaporator tubes will lead to freon leakage, which is a complex and expensive repair.
How to check a defrost heating element with a multimeter?
To check, you need to get to the heating element, remove the terminals from it and “ring” with a tester in resistance measurement mode. If the device shows infinity (one or OL), it means that the spiral is broken and the heating element requires replacement. Normal resistance is usually between 200 and 400 ohms.
Problems with the compressor and start relay
The compressor is the heart of the refrigerator, creating the pressure necessary to circulate the refrigerant. In single-compressor models, a decrease in motor performance can lead to a situation where the pressure is only enough to cool the freezer chamber located closer to the outlet of the compressor, and the freon reaches the refrigeration compartment not cold enough.
A common cause is wear of the motor-compressor. The piston group loses compression over time. The engine hums, trying to build up pressure, but cannot create a sufficient temperature difference in the secondary circuit. Also, the problem may lie in start-up protection relay. If the relay contacts are burnt or the mechanism is stuck, the compressor may not start the first time or work intermittently, which disrupts the cooling cycle.
Diagnostics of the compressor requires a professional approach, since it is necessary to measure current consumption and pressure in the system. However, you can carry out the initial inspection yourself:
- 🔊 Listen to how the motor starts: with a quiet hum or with a loud click and buzz.
- 🔥 Check the temperature of the case: the compressor should be warm, but not hot.
- ⚡ Pay attention to electricity consumption: the old motor may "waste" more light, working in vain.
If the compressor runs constantly without turning off, this is a sure sign that it cannot reach the set temperature in the refrigerator compartment. In such cases, the thermostat constantly requires cold, and a worn-out unit is physically unable to provide it in full.
Clogged capillary tube and refrigerant leak
Refrigerant circulation in the system occurs under high pressure through a very thin capillary tube. The diameter of its internal channel is a fraction of a millimeter. Even a microscopic particle of moisture that has turned into an ice plug, or a piece of oxidized metal can block the freon flow. In this case, the gas boils in the evaporator of the freezer compartment, but does not reach the evaporator of the refrigerator compartment.
Freon leakage is another critical problem. Refrigerant can escape through microcracks in the foam circuit, which are formed due to corrosion or vibration. If there is a partial leak, the amount of gas is only sufficient for the first cooling circuit (freezer). A characteristic sign of a leak is the absence of heating of the capacitor grid at the back of the device or its uneven heating.
The symptoms of a blockage or leak are often similar, and an accurate determination requires evacuation of the system and refilling with new gas. It is impossible to eliminate these faults on your own without special equipment (vacuum pump, pressure gauge station, scales).
| Symptom | Capillary clogged | Freon leakage | Compressor malfunction |
|---|---|---|---|
| Temperature in the freezer | Normal or slightly above normal | Above normal, food is melting | Above normal, the cycle is broken |
| Temperature in the refrigerator compartment | Warm, like in the room | Heat, no cooling | Heat, insufficient cold |
| Compressor operation | Works constantly or cyclically | Works constantly, without turning off | Humming, but does not start or running quietly |
| Condenser heating (rear) | Hot to the point of blockage | Barely warm or cold | May be hot |
Failure of electronics and sensors
Modern refrigerators are crammed with electronics. It is often responsible for the distribution of cold solenoid valve, which switches freon flows between the circuits of the freezing and refrigerating chambers. If the valve is stuck in the “freezer only” position or its control coil is burned out, cold will stop flowing into the upper compartment.
Temperature sensors also play an important role (thermistors). If the sensor in the refrigerator compartment fails and sends a false signal to the control module that “it’s already cold there,” the controller simply will not turn on the supply of refrigerant or fan to this compartment. A sensor error can be caused by oxidation of the contacts, a broken wire, or failure of the element itself.
Diagnostics of the electronic control unit (module) is complex and requires checking the output voltages. Often module failure occurs due to power surges in the network. Visually, swollen capacitors or traces of burning may be visible on the board, but often the malfunction is hidden.
Mechanical damage and operating errors
The reason does not always lie in complex technology. Sometimes x