The situation when a block of ice is found in the refrigerator compartment instead of fresh food, and vegetables turn to stone, is familiar to many owners of household appliances. This is not just an annoying nuisance, but a clear signal that temperature control system it has failed. When refrigerator starts to operate in freezer compartmentmode, this indicates that the compressor is not receiving a command to stop or the cold air damper is stuck open.
Ignoring this problem can lead to spoilage of a large number of products and even failure of the unit itself due to excessive load on the engine. Freezing chambers are always a consequence of an imbalance between the production of cold and its distribution. In this article, we will analyze in detail the mechanical and electronic reasons for this behavior of the equipment so that you can accurately determine the source of the malfunction.
Before calling a technician or disassembling the unit, it is necessary to carry out an initial diagnosis. Often the reason lies in trivial things that the user can fix on his own. However, if it is a Freon leak or breakdown of electronics, you cannot do without specialized equipment. Let's go through all possible scenarios one by one.
Malfunctions of the thermostat and thermostat
The most common reason why refrigerator it starts to freeze too much is the failure of the thermostat. This mechanical or electronic sensor is responsible for breaking the compressor power supply circuit when the set temperature is reached. If the contacts inside the thermostat are “stuck” in the closed state, the motor will work without stopping, turning the refrigerator compartment into a freezer.
In older models with mechanical control, displacement of the rod or leakage of the bellows tube filled with freon filler is often encountered. In such cases, the sensor simply “does not feel” that the temperature in the chamber is already below freezing. Electronic thermostats They may also malfunction due to oxidation of the contacts on the control board or damage to the touch panel itself.
Checking the thermostat requires caution. It is necessary to disconnect the device from the network, remove the casing and carefully disconnect the wires. Testing the contacts with a multimeter will show whether there is an open circuit when the position of the regulator changes. If the circuit does not break even when the sensor is strongly cooled (for example, by putting it in the freezer), the part must be replaced.
- 🧊 Continuous operation: The compressor hums without interruption, without going into rest mode, which leads to an increase in fur coat.
- 🧊 No click: When the regulator knob is turned to position “Off” or minimum cold, the characteristic click of the contacts opening is not heard.
- 🧊 Visual defects: Traces of oxidation, melting or mechanical damage to the bellows tube are visible on the thermostat body.
It is important to understand that replacing the thermostat is an operation that requires precision. Incorrect installation of a new part may result in the refrigerator not turning on at all or operating in abnormal mode. If you are not confident in your abilities, it is better to entrust this work to a professional.
Problems with the temperature sensor (for electronic systems)
In modern models, such as Liebherr, Bosch or Samsung with the system No Frost, it is not the mechanical one that is responsible for the temperature thermostat, but an electronic sensor (thermistor). Its resistance changes depending on the air temperature in the chamber. If the sensor transmits incorrect data to the on-board board (for example, it shows +10°C, when in reality it is already -5°C), the “brains” of the refrigerator will continue to drive the compressor.
Often the problem lies not in the sensor itself, but in the breakage of the wires going to it, or oxidation of the contacts in the connector. Moisture, condensation and temperature changes destroy insulation over time. It is also possible for the control module to freeze by software, which ignores the readings of a working sensor.
Diagnostics of the electronic sensor is carried out by measuring its resistance at different temperatures and comparing the obtained values with the resistance table for a specific model. A significant deviation from the norm indicates the need to replace the element. In some cases, flashing or replacing the control module itself is required.
⚠️ Attention! Before replacing electronic components, be sure to completely turn off the power to the refrigerator. Working with live electronics can lead to irreversible damage to the control board.
Symptoms of a sensor malfunction often manifest themselves in chaotic behavior of the equipment. The temperature may fluctuate, or the refrigerator may go into deep “overdrive”, freezing all contents. Error on the display This is the surest sign of a problem with the sensor, although not all models can display them.
Clogged capillary tube and freon leak
Paradoxically, sometimes the cause of ice formation in the refrigerator compartment is lack of refrigerant or partial blockage of the system. If freon leaks or the capillary tube is clogged, the refrigerant cannot circulate normally and release heat in the condenser. As a result, at the point of exit from the evaporator (often this is the area of the fridge compartment), a sharp expansion of gas and severe local hypothermia occurs.
Visually it may look like a huge lump of snow or ice in one corner of the back wall, while the rest of the chamber may be warm or have a temperature above normal. This phenomenon is called "snow coat". If the refrigerator operates cyclically, but a block of ice forms in the evaporator area, which interferes with normal air circulation, this is a sure sign of problems with the refrigerant.
Fixing such a malfunction requires calling a technician with equipment to evacuate the system, refill with freon and replace the filter-drier. It is impossible to solve this problem on your own, since access to the sealed circuit is required.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Ice only at the back wall | Clogged capillary or leak | Call a technician to repair the circuit |
| Ice throughout the chamber evenly | Malfunction of the thermostat/sensor | Replacing the thermostat or sensor |
| The refrigerator is not turns off | Stuck contacts or leakage | Diagnostics of thermostat and pressure |
| Temperature jumps | Problem with electronics | Checking the board control |
What is an “oxygen plug”?
This is a phenomenon when in the freon circulation system, along with oil and gas, there are oil breakdown products or moisture, which freeze in a narrow place in the capillary tube, blocking the refrigerant flow. After turning off the refrigerator, the plug thaws and it starts working again, but soon the cycle repeats.
Incorrect installation of the damper (Damper)
In two-chamber refrigerators with the system No Frost cold is supplied to the upper compartment through a special air duct covered by a damper (Damper). This damper opens and closes electronically to regulate the flow of cold air from the freezer compartment. If the damper mechanism is stuck in the open position or the drive motor is burned out, icy air will constantly blow into the refrigerator compartment.
Often the damper does not close completely due to ice. Moisture from food or a poorly closed door causes ice to form on the damper mechanism, which physically prevents it from closing. In this case, even working electronics will not be able to normalize the temperature.
To check, it is necessary to remove the air duct panel (usually located on the rear wall of the refrigerator compartment) and visually assess the condition of the damper. If it moves tightly or is blocked by ice, the unit must be completely defrosted within 24 hours. If the mechanism is working, but does not respond to commands, the damper motor will need to be replaced.
- ❄️ Constant draft: Strong cold air constantly blows from the air duct opening, even when it should be resting.
- ❄️ Ice crust: Ice has formed around the air supply opening, which is spreading to products.
- ❄️ Airflow noise: You can hear the constant noise of moving air, which does not stop for hours.
The influence of the “Super Freeze” mode and settings
Before committing damage, it is worth checking the settings. Many modern refrigerators are equipped with the Super Freeze or “Super Freeze” function. This mode is designed to quickly freeze large quantities of food and forces the compressor to work continuously. If you accidentally activated this function (or it turned on automatically and did not turn off according to the timer), the temperature in both chambers will drop to the minimum values.
It is also worth checking the set temperature mode. In some models, when setting the minimum temperature (for example, +2°C or +3°C) in combination with high chamber load or heat in the room, the unit may not have time to turn off, creating the effect of freezing at the rear wall.
Try resetting the settings to factory defaults or setting the average values (+4°C...+5°C). If after 5-6 hours of normal operation the situation does not change, then the problem is of a technical nature.
⚠️ Attention! The “Super Freeze” mode should not work constantly. Its long-term use (more than 24-48 hours) can lead to overheating of the compressor and shorten the service life of the equipment.
☑️ Check the settings before repair
When you need to call a specialist
There are a number of symptoms in which self-repair is not only useless, but also dangerous. If you find that refrigerator works without stopping, consuming a lot of electricity, and at the same time making uncharacteristic sounds (gurgling, whistling), most likely the problem is in the refrigerant circuit.
Also, the help of a specialist is necessary if, after defrosting and checking the settings, the problem returns after a short time. This indicates a hidden electronic or mechanical fault that is difficult to diagnose without instruments. An attempt to replace the compressor or seal the tubes yourself often leads to final breakdown of the unit.
Do not forget that intervention in a sealed circuit requires a license and special equipment. Using the wrong refrigerant or oil can damage a new compressor in a matter of days.
Frequently asked questions (FAQ)
Why did the water freeze in the refrigerator, although the thermostat is new?
If the thermostat is replaced, but the problem remains, it is possible that the new sensor has different characteristics (does not suit the temperature on/off) or its capillary tube is not installed correctly. Also, the reason may be a freon leak or a stuck damper.
Is it possible to temporarily use a refrigerator if it gets very cold?
It is possible to use it, but it is not advisable. The products will deteriorate (freeze), and the compressor will wear out. If it is not possible to fix it right away, try setting the regulator to minimum cold and ventilating the chamber more often, but this is only a temporary measure.
Only the back wall freezes - is this normal?
For a drip system (a “crying” refrigerator), the formation of ice on the back wall and its subsequent drainage is a normal operating cycle. You need to sound the alarm if the ice does not melt at all or turns into a thick coat that prevents the door from closing.
How often should you defrost the refrigerator to avoid problems?
Refrigerators with manual defrosting require defrosting 1-2 times a year. No Frost and drip systems do not require regular manual defrosting, but a preventive shutdown for a day every 1-2 years is useful for removing odors and checking seals.