The situation when Bosch refrigerator stops freezing always takes you by surprise, threatening food spoilage. This may happen suddenly, without any warning sounds or flashing lights. The owner discovers a problem when the food in the freezer begins to thaw, and the main department becomes unusually warm.
The reasons for this behavior of the equipment range from a banal valve sticking to a serious refrigerant leak. Modern models Bosch, such as series KGV or KGN, are equipped with complex electronics, which themselves diagnose some failures. However, primary diagnosis often requires a visual inspection and understanding of the principles of operation of the system No Frost.
It is important not to panic and consistently check all possible factors. In some cases, the problem is solved by simple defrosting, in others, the intervention of a specialist with professional equipment for refilling freon is required. Ignoring the first signs of a malfunction can lead to failure of an expensive compressor. Attention: If you hear a loud knock or hum when you try to start the engine, immediately unplug the device. Further operation in this mode is guaranteed to lead to combustion of the motor windings. compressor.
⚠️ Attention: If you hear a loud knock or hum when you try to start the engine, immediately unplug the device. Further operation in this mode is guaranteed to lead to burnout of the motor windings.
Primary diagnostics: light, sound and indication
The first thing to do if Bosch refrigerator does not freeze is to evaluate its external manifestations. Is the light inside lit? Can you hear the hum of the engine? Many models have a display or system of flashing lights that indicate rising temperatures. For example, a flashing snowflake symbol often indicates that the temperature in the chamber is higher than the set norm.
Listen to the operation of the unit. If the engine hums, but there is no cold, the circulation of the refrigerant may be impaired. If there is deathly silence, the problem may be in the start relay or electronic control module. In models with the system Multi Airflow the absence of fan noise also indicates that the cold air supply is blocked.
Check the tightness of the doors. Even a microscopic gap in the seal leads to a constant flow of warm air. The compressor works hard, trying to compensate for heat loss, but at some point it stops coping and the temperature begins to rise. This is especially true for old rubber seals, which harden over time.
Problems with the defrosting system (No Frost)
The most common reason why The Bosch refrigerator has stopped freezingis a malfunction of the automatic defrosting system. In models No Frost frost constantly forms on the evaporator, which must periodically thaw. If this process is disrupted, the ice coat grows and blocks the channels for supplying cold air to the chambers.
Visually it may look like this: it’s cold in the freezer, but it’s warm in the refrigerator compartment, or there is cold, but very weak. Three main elements are responsible for the defrosting process: Evaporator heating element, defrost sensor and timer (or electronic module). The failure of any of them stops the defrosting cycle.
If the heating element is burned out, the ice does not melt. If the sensor “lies” and shows that there is no ice, the control module will not turn on the heating. As a result, the fan begins to drive air through the ice plug, and the cooling efficiency drops to zero. In such cases, it is necessary to completely defrost the refrigerator within 24 hours to test the hypothesis.
☑️ Symptoms of faulty defrosting
It is worth noting that in some models Bosch with a double cooling circuit (Duo Cooling) the defrost system may be divided. This means that ice can melt in the refrigerator compartment, and accumulate in the freezer if a specific circuit is faulty.
Freon leakage: signs and consequences
When Bosch refrigerator works constantly without turning off, but the temperature does not drop to the set values, there is a high probability of a refrigerant leak. Freon is a working fluid that transfers heat. If its quantity in the system is critically reduced, the compressor simply cannot create the necessary pressure for cooling.
Leaks often occur in the foamed parts of the housing due to corrosion of the evaporator tubes or at soldering points. It is difficult to visually notice the location of the leak, since the gas is colorless and odorless. An indirect sign may be swelling of the inner wall of the refrigerator compartment or the appearance of oily spots near the compressor.
⚠️ Attention: Self-filling with freon without vacuuming the system and searching for leaks is prohibited. This is a temporary measure that will lead to repeated failure in a few weeks and failure of the compressor.
If a leak occurs, air and moisture inevitably enter the system. Before refilling, the technician must evacuate the circuit to remove moisture. Moisture in the system is a risk of ice plugs forming in the capillary tube and corrosion of the internal elements of the compressor.
Why can’t you just add freon?
If there is a leak in the system, adding gas will not solve the problem. The pressure will drop again, and the compressor will work at its limit, trying to compensate for the lack of refrigerant, which will lead to its overheating and wedge.
Faults of the compressor and start relay
The heart of the refrigerator is compressor. If it fails, the cold ceases to be produced physically. Symptoms can be different: the engine hums for a few seconds and clicks while trying to start, or is completely silent. In inverter models Bosch diagnosis is more difficult, since they start smoothly and quietly.
Often the culprit is not the motor itself, but starting relay. This device provides a starting impulse. If the relay contacts are burnt or the mechanism is stuck, the compressor winding does not receive the required current. Replacing the relay is one of the simplest and cheapest repair procedures that you can do yourself.
In the case of inverter compressors, the problem may lie in the control module that converts the current. Power surges in the network often damage these electronics. A sign of an inverter malfunction may be the absence of the characteristic hum and vibration characteristic of conventional motors.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| Clicks and buzzes for 5-10 seconds, then silence | Start relay or jammed compressor | Low / High |
| Works constantly without turning off | Freon leak or clogged capillary | High |
| Complete silence, there is light | Malfunction of the control module or thermostat | Medium |
| Humming, but there is no cold at all | Compressor failure (no compression) | High (replacement) |
Clogged capillary tube
Another technical reason why Bosch refrigerator it freezes poorly - clogged capillary tubes. This is a thin pipeline through which freon enters the evaporator. The blockage can be caused by oil oxidation products that entered the system during installation, or by moisture that has turned into an ice plug.
If a blockage occurs, the circulation of the refrigerant is disrupted. The compressor tries to push gas, the discharge pressure increases, and the suction pressure drops. As a result, the evaporator either does not cool at all, or only its initial part is cooled. A characteristic sign is that the compressor is overheating - it becomes hot to the touch.
To eliminate this problem, it is necessary to purge the system with nitrogen under high pressure and replace the filter drier. The filter traps moisture and debris, and if it is clogged, the system will not work. This procedure requires specialized equipment and skills.
Failures in the electronic control module
Modern refrigerators Bosch are controlled electronically. If control module (the board) fails, it may not send a signal to start the compressor or fan. This often happens after power surges or lightning strikes.
Visually, traces of burning or swollen capacitors may be visible on the board. However, in 80% of cases there are no external signs, and the board looks absolutely intact. In such cases, professional diagnostics using a tester and circuits are required.
Sometimes the problem is solved by resetting the errors (rebooting). To do this, the refrigerator must be unplugged for 15–20 minutes. If, after turning on, the system again goes into error or does not start, most likely you will need to replace the module or resolder the burnt elements.
⚠️ Attention: When replacing an electronic module, it is important to take into account the modification of the board. Even within the same model Bosch different versions of firmware and boards may be used that are incompatible with each other.
Frequently asked questions (FAQ)
Why does a Bosch refrigerator freeze in only one compartment?
This is a characteristic sign of a system malfunction No Frost or a blockage in the circuit. If the upper chamber does not freeze, the air supply channels are most likely clogged with ice. If the problem is in the freezer, there may be a freon leak or a compressor malfunction.
How long should defrosting last during diagnosis?
To completely melt the ice in the hidden cavities of the evaporator and the drainage system, it is recommended to defrost the refrigerator for at least 24 hours. The minimum time is 12 hours, but it may not be enough to eliminate ice jams.
Is it possible to operate the refrigerator if it has stopped freezing?
For a short time - yes, to preserve food by moving it to another place. But you cannot keep a faulty unit turned on for a long time. This will lead to overheating and combustion of the compressor, which will make repairs economically unfeasible.
What does the flashing Alarm indicator on a Bosch refrigerator mean?
The indicator Alarm signals a critical increase in temperature in the chamber. It lights up if the door has been open for a long time or if the refrigerator has stopped freezing due to a technical malfunction. After eliminating the cause and reducing the temperature, it goes out on its own.