The situation when food freezes through in the freezer, but the main compartment is warm or the temperature is above normal, is one of the most common complaints from home appliance owners. This contradiction often confuses inexperienced users, since it is logical to assume that if cold is produced, it should be distributed evenly throughout the entire volume of the device. However, the design of modern units, especially models with the system No Frostimplies a complex scheme of air circulation and compressor operation.
Most often, the problem lies not in a complete stop of the cooling system, but in a disruption of heat exchange between compartments or failures in the electronics operating algorithms. Understanding the physical processes occurring inside the case will help you not to panic and correctly diagnose the problem before calling a technician. In this article we will analyze in detail the mechanical, electrical and software reasons for this behavior of the equipment.
It is important to note that ignoring the primary symptoms can lead to more serious consequences, including the failure of an expensive compressor or complete spoilage of food. Therefore, upon detecting a temperature imbalance, it is necessary to immediately carry out primary diagnostics. Below we will look at the main breakdown scenarios and how to fix them.
Principle of operation and distribution of cold
To understand why the temperature regime was disrupted, you need to briefly understand the structure of the refrigerator. In classic single-compressor models, the cold is produced in the evaporator, which is most often located in the freezer. Then, using a fan or natural convection, the cooled air is moved into the refrigerator compartment. If this process is disrupted, a situation arises when freezer works in normal mode, and the upper compartment is warm.
In systems No Frost a special fan is responsible for circulation. It forces air through the evaporator and directs flows into different chambers through special channels and dampers. If the fan stops or the channels are blocked by an ice plug, the cold stops flowing into the main compartment, remaining localized in the evaporator area. In drip systems (“crying” refrigerator), the role is played by the correct operation of the thermostat and the absence of obstacles to the natural movement of air masses.
The key element here is not only the generation of cold, but also its transport. Any breakdown in the “evaporator - fan - channels - damper” circuit leads to the problem described. Modern models can be equipped with two evaporators, but even they often use one compressor, and a failure in air flow control causes an imbalance.
Checking the thermostat and temperature sensors
One One of the first reasons why the compressor may not turn on often enough or work incorrectly is a malfunction of the thermostat. This component is responsible for reading the temperature inside the chamber and sending a signal to turn the motor on or off. If the sensor “freezes” at low values, the compressor will think that it is already cold in the refrigerator and will not start, although in reality it is warm there.
In electronic models, thermal sensors (thermistors) are responsible for this process. Their resistance changes depending on temperature. If the sensor fails and shows incorrect data, the control module does not give a command to cool the main compartment. Often the problem is solved by replacing the sensor, which is inexpensive, but requires disassembling the internal panel.
Mechanical thermostats are characterized by wear of the bellows tube. If the tube has lost its seal or has become displaced, it cannot correctly transmit freon pressure inside the capillary, which leads to incorrect contact closure. You can check this by temporarily closing the thermostat contacts: if the refrigerator is working at full capacity, then the problem is in this unit.
⚠️ Attention! Before checking the electrical components, be sure to unplug the refrigerator. Working with live electrical wiring is life-threatening.
You should also pay attention to the settings. Sometimes users accidentally turn off the Eco mode or minimum cooling, thinking that the equipment is broken. Make sure that the regulator is not set to minimum.
Problems with the fan and the No Frost system
In units with an automatic defrosting system, the fan plays the role of the heart of the air distribution system. If it does not spin, cold air remains in the freezer and does not enter the refrigerator. This is the most common reason for the situation when the temperature in the freezer is -18°C, and in the refrigerator compartment is +10°C and above.
The reasons for stopping the fan can be the following:
- ❄️ Freezing of the blades: if the defrosting system does not work correctly, the ice blocks rotation.
- 🔌 Motor malfunction: the winding is burned out or the bearing of the fan itself is jammed.
- 🔌 Problems with the wiring: contacts are oxidized or the fan power supply circuit is broken.
- 🧊 Clogged air ducts: an ice plug in the channel does not allow air to pass even when running fan.
Diagnostics of the fan is usually simple: you need to open the freezer door (in some models it turns off when the door is open, so you need to find and press the door sensor button) and listen. If there is no sound of operation, and a thick layer of ice is visible on the evaporator, most likely the problem is in the defrost system.
If the fan hums but does not rotate, it needs to be changed. If it is covered with ice, the refrigerator will need to be completely defrosted within 10-12 hours. Often, after defrosting, the equipment begins to work properly, which indicates a failure in the defrosting cycle.
☑️ Fan diagnostics
Malfunctions of the defrost system (heating element, timer, sensor)
The system No Frost periodically heats the evaporator to melt the ice. The heating element (heating element), defrost sensor and timer (or electronic module) are responsible for this process. If any of these elements fails, a “coat” of ice grows on the evaporator, which blocks the air supply channels to the refrigerator compartment.
Visually it looks like this: the freezer freezes very hard (since ice interferes with heat transfer, the compressor works longer), but there is no cold in the main chamber. Ice blocks air intake and supply. To check, you need to remove the back panel of the freezer. If the evaporator is covered with ice and the fan is clean, then the defrosting system did not work.
Main components that require checking:
- 🔥 Defrost heating element: must be called by the tester (have resistance). If there is a break, the heating element has burned out.
- 🌡️ Defrost sensor: should open the circuit when a certain temperature is reached. It often fails first.
- ⏱️ Defrost timer: a mechanical or electronic unit that switches the “cooling” and “defrost” modes.
⚠️ Attention! Do not try to break off the ice with a knife or sharp objects. Damage to the evaporator tubes will lead to freon leakage and costly repairs. Use only a hairdryer or natural defrosting.
Replacing a heating element or sensor is a procedure that can be done with your own hands if you have a multimeter and basic skills. The main thing is to find compatible spare parts for your model Indesit, Bosch, Samsung or another brand.
Freon leakage and blockage of the capillary system
If after defrosting the problem does not disappear, or if you hear that the compressor is running almost continuously, but there is not enough cold, there may be a refrigerant leak. Freon is a working fluid that transfers heat. If there is not enough of it, then at the beginning of the circuit (in the freezer) it may still be cold, and the freon simply does not reach the end of the circuit (refrigerator compartment) or does not have time to boil.
Signs of a leak:
- 📉 The compressor works constantly without turning off.
- 🔥 The condenser (grid at the back) is only partially warm or cold.
- 💧 Bloating of the back wall inside the refrigerator (the place where the evaporator is sealed).
Another similar problem is clogging of the capillary tube. An ice or oil plug forms in the system, which interferes with the circulation of freon. The symptoms are similar to a leak: the freezer works, the refrigerator does not, the compressor is hot and humming. In both cases, the intervention of a specialist with equipment for vacuuming and filling is required.
It is impossible to eliminate the leak or blockage on your own. It requires searching for the location of the damage, soldering, replacing the filter-drier and refilling with new freon. Attempts to “gas up” the system without eliminating the cause will only give a temporary effect.
Is it possible to add freon yourself?
No, this requires specialized equipment and skills. In addition, you need to know the type of freon and the amount of oil in the system. Incorrect refueling will kill the compressor.
Failures in the operation of the electronic control module
In modern refrigerator models, the entire process is controlled by an electronic “brain”. If the control board fails, it may send incorrect signals. For example, open the freon supply valve only to the freezer or do not turn on the blower fan.
Often failures occur due to power surges in the network. The symptoms may be strange: the refrigerator turns on and off randomly, the indicators on the panel blink, or the appliance does not respond to buttons at all. In some cases, a reboot helps (disconnect from the network for 15-20 minutes), but if the problem is burnt-out board elements, the module will need to be repaired or replaced.
Module diagnostics are complex and require knowledge in electronics. The technician checks the presence of control signals on the compressor and fan relays. If there are signals, but the actuators do not work, the problem lies with them. If there are no signals, the module is faulty.
Diagnostic table: The freezer works, the refrigerator does not
For convenience, we systematize the main symptoms and probable causes in the table. This will help narrow down the troubleshooting.
| Symptom | Probable cause | Difficulty of repair | Action |
|---|---|---|---|
| The compressor is humming, but not turns off | Freon leak or blockage | High (needs a technician) | Call a specialist to look for a leak |
| There is a coat of ice in the freezer | System malfunction defrost (heating element, sensor) | Medium | Defrost, check the heating element and sensor |
| The fan does not spin | The fan motor is frozen or broken | Low/Medium | Defrost, replace the fan |
| The refrigerator does not turn on at all | The thermostat or module is faulty | Medium | Check the thermostat, contact closure |
| Temperature floats, indicators blink | Electronics or sensors failure | High | Diagnostics of the control module |
As can be seen from the table, in most cases the problem can be localized by external signs. However, an accurate diagnosis often requires disassembling the components.
Frequently asked questions (FAQ)
How long does it take to defrost the refrigerator to check?
For complete and high-quality defrosting, especially if there is a suspicion of an ice plug in the channels, the refrigerator should stand turned off with the doors open for a minimum 10-12 hours, or better yet, 24 hours. A short-term defrosting of 2-3 hours may not melt the ice in the hidden channels.
Could the reason be in the sealing rubber band?
Yes, if the rubber band of the refrigerator compartment allows heat to pass through, the compressor may not cope with the cooling, although the freezer will be cold. Check the tight fit of the door: clamp a sheet of paper between the door and the body - it should be pulled out with force along the entire perimeter.
Why did the refrigerator work after defrosting, but a week later everything happened again?
This is a sure sign of a malfunction of the defrost system (heating element, defrost sensor or timer). Defrosting removed the consequences (ice), but did not eliminate the cause (non-heating heating element). The defective part needs to be replaced.
Is it dangerous to use the refrigerator if the freezer is working but the refrigerator is not?
You cannot use the refrigerator compartment - the food will spoil. Operating the unit in this mode for a long time is also harmful for the compressor, since it can work without interruption, trying to gain temperature, which will lead to its overheating and combustion.
Is it necessary to change the filter drier during repairs?
If the freon circulation circuit was opened (there was a leak, blockage or replacement of the compressor), Replacement of the filter drier is mandatory. It absorbs moisture from the system, and if the seal is broken, it loses its properties. Reusing the old filter is prohibited.