The situation when the refrigerator begins to excessively freeze food in the main chamber takes many owners by surprise. Instead of fresh vegetables and chilled drinks, you find frozen lumps of soup and an icy crust on milk. This is not just an inconvenience, it is a signal that thermal regulation system is not working correctly.
Such a malfunction cannot be ignored, as it can lead to damage to expensive equipment. A worn-out compressor will quickly fail, and restoring the tightness of the circuit will require serious investments. Overcooling of the main chamber is most often caused by a refrigerant leak or a stuck thermostat.
In this article we will analyze in detail the mechanics of the process, list the main reasons and offer a step-by-step action plan. You don't need to be an engineer to understand the problem, but a basic understanding of the cooling cycle refrigeration cycle
The principle of operation and role of the thermostat
To understand why ice forms in the refrigerator compartment, you need to briefly look at the operating diagram. The refrigerant (freon) circulates through the system, taking heat from the chambers and releasing it to the environment through the condenser. The key control element for this process is thermostat (thermostat).
It is this sensor that “tells” the compressor when to turn on and when to stop. If it transmits incorrect data or its contacts are stuck closed, the compressor continues to operate continuously. As a result, the temperature drops below the permissible minimum, and the products in the main chamber begin to freeze.
⚠️ Attention: Constant operation of the compressor without stopping is a critical mode. If you hear that the motor is humming 24 hours a day without rest breaks, immediately disconnect the device from the network to avoid a fire or burnout of the winding.
In modern models with the system No Frost an electronic control module is also responsible for the process. It receives signals from several temperature sensors. If one of the sensors “lies” or fails, the “brains” of the refrigerator may make an erroneous decision about the need for intensive cooling.
Malfunctions of the thermostat and sensors
The most common reason why the refrigerator freezes more than expected lies in the mechanical or electronic thermostat. Older models use a capillary tube filled with gas or liquid. When it expands or contracts, it opens or closes the contacts.
Over time, the mechanism wears out, and the contacts can “weld” or stick. In this case, the circuit does not open even when the temperature reaches a low temperature. The compressor receives power constantly. In electronically controlled devices, the problem is caused by failed thermal sensors temperature sensors.
Diagnosis of this malfunction requires a multimeter. It is necessary to “ring” the thermostat contacts at different temperatures. If no opening occurs during cooling, the part must be replaced. Independent replacement is possible, but requires disassembling the case.
Symptoms of a faulty thermostat
The thermostat is considered faulty if the compressor does not turn off even with the minimum regulator settings, or if the refrigerator does not turn on at all when the knob is turned to the extreme position.>
Problems with the refrigerant and defrost system
Paradoxically, a freon leak can also lead to local hypothermia. When the amount of gas in the circuit decreases, the compressor is forced to work longer to reach the desired temperature. As a result, a powerful ice ball forms at the point where freon enters the evaporator (usually the back wall).
This cold front can spread to nearby products. This is especially common in single-compressor models. The system defrost also plays an important role. If the defrost heating element is burnt out or the timer does not turn on the defrost mode, the evaporator becomes overgrown with a “fur coat”. As a result, food on the upper shelves, closer to the freezer, may freeze while it is warm below.
Ice blocks normal air circulation (in No Frost) or directly contacts the shelves. As a result, food on the upper shelves, closer to the freezer, may freeze while it is warm below.
- 🧊 Freon leakage is often accompanied by a change in the shape of the evaporator or the appearance of oily spots.
- ❄️ A malfunction of the defrost heating element leads to a build-up of ice, which is visible through the holes on the back wall.
- ⏱️ Failure of the defrost timer is less common, but completely stops the defrosting cycle.
Influence of operating mode and settings
Before sounding the alarm and calling a technician, it is worth checking the settings. Sometimes users accidentally activate the "Super Freeze" (Super Freeze) mode. In this mode, the refrigerator ignores the thermostat readings and freezes as intensely as possible.
Usually this mode turns off automatically after 24-48 hours, but if the function is stuck or turned on manually, the food in the main chamber may be damaged. It is also worth checking the position of the temperature regulator. If it is turned to maximum (usually the numbers 6 or 7, or the inscription Max), the compressor will work almost without interruption.
⚠️ Attention: In the summer, when the ambient temperature is high, setting the regulator to maximum can lead to freezing of the rear wall and spoilage of food. It is recommended to set average values (3–4).
Check whether the fast freezing mode is turned on on the control panel. The indicator is usually red or flashing. To turn it off, press the corresponding button or turn the knob to the “Off” position.
☑️ Checking the refrigerator settings
Fault diagnosis table
To make it easier to find the problem, you can use the summary table. It will help to compare the visible signs with the probable causes of the breakdown.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The compressor hums non-stop | Thermostat is faulty or freon leak | Medium / High |
| Ice only at the back wall | Capillary clogged or lack of freon | High (need master) |
| Products are freezing, the motor is silent | Electronics or sensors failure | Average |
| Frost throughout the chamber | Tight fit of the door or defect seal | Low |
As can be seen from the table, some problems require the intervention of a specialist with equipment for charging freon, while others can be solved independently. Leakage refrigerant - this is a complex case that requires finding the location of damage, soldering and vacuuming the system.
Tightness of the door and seals
A frequent but common cause of problems is chamber leakage. If sealing rubber (cuff) on the door is worn out, dirty or deformed, warm air constantly flows inside.
The refrigerator “feels” the increase in temperature and turns on the compressor at full power, trying to compensate for heat loss. This leads to the formation of a thick layer of ice on the back wall and overcooling of the food.
Also check whether the door is warped. Heavy products on the door shelves can pull it down, breaking the seal. Adjust the legs of the refrigerator or hang the door if the design allows.
What to do: algorithm of actions
If you find that the refrigerator is freezing food, act consistently. Rule out simple causes first before dismantling the appliance. This will save time and money.
- Turn off the “Super Freeze” mode and reduce the cooling power.
- Defrost the refrigerator completely (at least 12-24 hours) with the doors open.
- Check the cleanliness of the condenser (grid at the back) and the tightness of the door.
- If after turning on the problem returns after a few hours, call a technician.
Independent repair of the cooling system (replacing freon, soldering pipes) at home is impossible without special equipment and a license. However, the user can replace the thermostat or sensor himself if he has electrical skills.
Frequently asked questions (FAQ)
Why do vegetables freeze in drawers, although the thermostat is set to minimum?
This may indicate a malfunction of the damper that regulates the supply of cold air from the freezer (in dual-circuit systems), or that the thermostat is “lying” and does not give the command to stop the compressor. Also check whether you are blocking the air circulation holes with food.
Is it possible to (use) a refrigerator if it gets very cold?
Short-term - yes, but this is harmful for the compressor, which wears out. Products in the main chamber will deteriorate (freeze), losing their taste. It is better (as soon as possible) to eliminate the cause.
How much does it cost to replace a thermostat?
The cost consists of the price of the part itself and the work of the technician. Mechanical thermostats are cheaper than electronic sensors. The exact price can only be found out after diagnostics, since the cost may vary depending on the model of the refrigerator.
Why, after defrosting, did the refrigerator start freezing again after 2 days?
Defrosting is a temporary solution if there is a technical fault. The ice has melted, the water has gone away, but the cause (for example, a stuck thermostat or a freon leak) has not gone away. The cycle will repeat again.