A sudden change in temperature inside the refrigeration chamber is always a signal that a malfunction has occurred in the operation of the unit. If you notice that the food in the refrigerator compartment has begun to freeze, and a thick layer of ice or frost has appeared on the walls where there was none before, you cannot ignore this. Impaired temperature balance This can lead not only to food spoilage, but also to the failure of expensive compressor components.
Causes: why the refrigerator began to freeze more than usual, there can be many reasons: from a banal error in the settings to a serious refrigerant leaks or failure of the electronics. In this article, we will examine in detail the mechanics of the cooling system so that you can understand where exactly the problem lies. Often, users panic ahead of time without checking simple parameters, but in some cases immediate intervention by a technician is required.
The first thing to do is to analyze the nature of the problem. Does it freeze constantly or cyclically? Did the ice appear only on the back wall or is it all over the product? Answering these questions will help narrow your search. Next, we will look at the main technical and operational factors that influence cooling intensity.
Errors in settings and operation
Before looking for complex technical faults, it is worth eliminating the human factor. Often the reason lies in accidentally changed settings or incorrect placement of products. If you have recently defrosted the unit or moved it, you may have accidentally set the temperature controller to maximum cooling mode.
In models with electronic control, a failure could have occurred due to a power surge. In such cases control module he could reset the settings to factory settings or, conversely, go into emergency mode of enhanced operation. It is also worth checking if the Super Freeze function is turned on, which is designed to quickly freeze large volumes of food and does not turn off automatically in some older models.
- ❄️ Check the position of the thermostat: in mechanical models it could have shifted to number 6 or 7 (maximum).
- 🥩 Make sure that the "Super Freeze" or "Quick Cool" function is not activated accidentally.
- 🌡️ Check the temperature zone settings in the electronic display, if there is one.
Another common mistake is placing warm or high-humidity foods in close proximity to the temperature sensors or evaporator. This can disorient the system, causing the compressor to run continuously. In addition, loading the chamber too tightly or, conversely, storing food in open containers affects air circulation.
⚠️ Attention: If you use the “Vacation” or “Eco” mode, but the refrigerator freezes more, then the problem is not in the settings, but in the hardware. Energy saving modes usually raise the temperature rather than lower it.
Malfunctions of the thermostat and temperature sensors
One of the most common reasons why the refrigerator starts to freeze in the refrigerator compartment is failure of thermostat (thermostat). This component is responsible for sending a signal to the compressor to turn on and increase. If the thermostat contacts “stick” in the closed state, the compressor receives a command to work continuously without stopping to rest.
In modern models with a system No Frost or Full No Frost instead of a mechanical thermostat, electronic sensors (thermistors) are used. They transmit temperature data to the board. If the sensor “lies” and shows that it is warm in the chamber, although in fact it is already minus, the board will drive the motor-compressor until everything freezes.
Diagnostics of the thermostat at home is difficult, since it requires testing the contacts with a multimeter at different temperatures. However, there are indirect signs: if the compressor works without stopping, and a “snowdrift” forms inside, most likely the temperature regulator is to blame temperature controller.
- 🔧 The mechanical thermostat could have lost the seal of the bellows tube.
- 📉 The electronic sensor could have oxidized or been damaged wiring.
- ⚡ The control board could no longer correctly read the readings of a working sensor.
Replacing a thermostat is not the most difficult procedure for a technician, but it requires precision. In mechanical models, it is important to choose an analogue with identical characteristics, otherwise the refrigerator will not work correctly. Electronic models often require not just replacement, but also calibration or resetting errors in the controller's memory.
☑️ Diagnostics of the thermostat
Problems with the defrost system (for No Frost)
If your refrigerator is equipped with a system No Frost, then the formation of ice in the refrigerator compartment (and not just in the freezer) often indicates a failure in the evaporator defrost system. Normally, the ice that accumulates on the hidden evaporator should be periodically melted by heating elements, and the water should go into the drainage. If this process is disrupted, the ice coat grows and blocks the cold air supply channels.
As a result, cold air from the freezer, instead of circulating according to a given algorithm, begins to flow uncontrollably into the refrigerator compartment. The temperature sensor in the refrigerator compartment may not have time to respond, or the flow of cold air is so intense that it freezes everything around. Key elements that may fail:
- Defrost heating element - burns out and does not heat.
- Defrost sensor - does not give a command to turn on the heater.
- Defrost timer or control module —does not initiate the defrost cycle.
A symptom of such a breakdown is often that the refrigerator freezes in jerks or after complete defrosting (on 10-14 hours) starts working normally until the next defrost cycle, after which the situation repeats. “Snowflakes” or drops of water may appear on the back wall of the refrigerator compartment and freeze.
⚠️ Attention: Operating the refrigerator with a defrosting system that is not working leads to ice accumulation on the fan. This can cause it to jam, produce loud noise and, as a result, overheat the fan motor or break the wiring.
How to check the defrost heating element?
To check the heating element, you need to get to the evaporator (usually behind the back panel in the freezer). The heating element is checked with a multimeter: if the resistance is infinitely high, the heater has burned out and requires replacement. Also visually inspect it for swelling or ruptures in the spiral.
Freon leakage and compressor operation
Paradoxically, a refrigerant (freon) leak can also lead to local hypothermia, although more often we expect a complete absence of cold. When there is little freon left in the system, the compressor is forced to work almost non-stop, trying to reach the set temperature. Under such conditions, an ice lump may form in the first part of the evaporator (which is located closer to the outlet of the freezer or in the refrigerator compartment area in some models).
This ice build-up begins to freeze everything that is nearby. The main sign of a leak is long, continuous operation of the compressor and hot sides of the housing (or, conversely, cold if the freon is completely gone, but at the initial stage they may be hot due to overload). Ice generator in such systems it may not work correctly.
It is difficult to determine a leak visually, since freon is colorless and odorless. Craftsmen use leak detectors or the nitrogen pressure test method. You can independently notice only indirect signs:
- 🌬️ The compressor hums continuously, without rest cycles.
- 🧊 Ice forms only in one specific place (locally).
- 🌡️ In other parts of the chamber, the temperature may be higher than normal.
It is important to understand that simply “refilling” the refrigerator in the event of a leak is not enough. It is necessary to find where the circuit is damaged, solder it and only then refill the system. Otherwise, the gas will leave again in a few days or weeks.
Failures of the control module and electronics
In modern refrigerators such as Liebherr, Bosch or LG, the entire process is controlled by sophisticated electronics. If board (the control module) fails, it may send incorrect commands to the actuators. For example, the compressor start relay may “stick”, or the board may ignore signals from temperature sensors.
Often problems with electronics arise after power surges in the network. Even if there are visually no traces of burning on the board, the microcircuits could be damaged. In such cases, the refrigerator can behave unpredictably: either it freezes too much, or it stops cooling altogether. Diagnostics requires special equipment and knowledge of circuit design.
Sometimes the problem is solved by flashing the module or resetting it (hard reset), but more often it is necessary to replace the board or its individual components (relays, triacs). If you notice that errors are on the display or the indicators are blinking in an unusual manner, this is a direct path to checking the electronics.
⚠️ Attention: Before replacing the control module, be sure to ensure that all sensors and wiring are in good working order. Installing a new board on faulty sensors can lead to the burning of a new expensive component.
Table of main symptoms and causes
For ease of diagnosis, we have systematized the main symptoms of malfunctions. Compare the symptoms of your equipment with the data in the table to understand the search vector for the problem.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| Ice all over the back wall, the compressor does not turn off | Thermostat or temperature sensor is faulty | Medium |
| Ice at the bottom of the refrigerator compartment, water on the floor | The drainage is clogged or the defrost system is faulty (No Frost) | Medium/High |
| Local ice lump, compressor runs constantly | Freon leakage or capillary blockage | High (needs a technician) |
| Chaotic temperature change, errors on the display | Failure of the control module or wiring | High |
| Food freezes only at the back wall | Incorrect setting or poor air circulation | Low (independently) |
As can be seen from the table, many problems require professional diagnostics. Self-repair of components related to refrigerant or complex electronics can be dangerous and ineffective.
Frequent questions and answers (FAQ)
Is it possible to use a refrigerator if it gets very cold?
Short-term use is possible, but not advisable. Constant wear and tear on the compressor reduces its service life. In addition, frozen food can damage the packaging and contaminate the chamber, and ice can damage fans or plastic elements.
Why, after defrosting, did the refrigerator start to freeze again after a week?
Most likely, your automatic defrosting system (heating element, sensor or timer) is faulty. Manual defrosting removes ice, but does not eliminate the cause of its appearance. After a cycle of operation, the ice builds up again, blocking the air ducts.
How to move a mechanical thermostat to the middle position?
Usually the thermostat scale has numbers from 1 to 7. The middle position is considered to be 3 or 4. If the refrigerator freezes too much, try reducing the value by 1-2 divisions and wait 24 hours for temperature stabilization.
Does the rubber seal cause the refrigerator to freeze?
A bad seal usually causes the refrigerator to freeze worseas heat gets inside. However, if warm air gets to the temperature sensor, it can cause the compressor to work longer, which indirectly leads to overcooling of other zones, although this is a less typical scenario.