The situation when Bosch refrigerator stops turning off is familiar to many equipment owners. Instead of the usual rhythmic hum and periods of silence, the unit works non-stop, trying to achieve the set temperature parameters. This not only leads to a significant increase in energy bills, but also creates constant background noise in the apartment.
The problem is based on a violation of the thermal balance: the cooling system cannot reach the desired temperature, so compressor continues to work without interruption. Modern models, such as Series 6 or VitaFresh, are equipped with smart electronics that can signal a problem by flashing indicators or an audible signal. However, in older or simpler models, the only sign of a malfunction is the continuous operation of the motor.
Ignoring this symptom can lead to complete failure of an expensive compressor, the replacement of which is often comparable in cost to buying a new refrigerator. The critical threshold is the operation of the compressor for more than 24 hours without stopping for cooling. In this material we will analyze in detail the technical reasons and diagnostic methods and troubleshooting methods.
Increased thermal load and problems with the seal
One of the most common reasons why the refrigerator Bosch does not turn off is banal penetration of warm air from outside. If heat is constantly entering the chamber, the electronics or mechanical thermostat will not command the engine to stop because the target temperature inside has not been reached. Often the culprit is the rubber door seal. Over time, the rubber loses its elasticity, cracks or deforms, forming gaps. Even a microscopic gap leads to a constant flow of warm air and the formation of ice, which further complicates heat exchange. Owners of models with the system seal doors.
Over time, rubber loses elasticity, cracks or deforms, forming gaps. Even a microscopic gap leads to a constant flow of warm air and the formation of ice, which further complicates heat exchange. For owners of models with the system NoFrost should be especially careful, since a violation of the tightness quickly disables the defrosting system.
You can check the tightness in a simple but effective way. Take a regular sheet of paper or a bill and clamp it with the refrigerator door around the perimeter. If the paper falls out or is pulled out without noticeable resistance, it means that the seal does not fit tightly in this place.
☑️ Diagnosis of the seal
It is also worth paying attention to the frequency of opening the doors. If the house is hot, and you often look into the refrigerator or leave the door open while cooking, the compressor simply does not have time to cool the volume of the chamber. In the summer, the heat load on equipment increases significantly.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” that controls turning the compressor on and off. In mechanical models Bosch this device is a relay with a bellows that responds to changes in refrigerant pressure in the capillary tube. If the contacts inside the thermostat “stick” in the closed position, the compressor will run indefinitely.
In modern electronically controlled refrigerators, the thermostat function is performed temperature sensors. They are located in different areas: in the evaporator, in the refrigerator, in the freezer. Failure of any of these sensors may result in incorrect readings for the control board. The electronics “thinks” that the chamber is warm and causes the motor to work.
⚠️ Attention: Replacing the thermostat in Bosch refrigerators requires disassembling the unit and, in some models, removing the evaporator. If you do not have experience working with electrical circuits, it is better to entrust this procedure to a specialist.
Diagnostics of the thermostat in mechanical models is often carried out by the method of elimination. You can try temporarily shorting the wires going to the thermostat (after unplugging the refrigerator!). If after switching on the compressor starts working, then the problem is in the regulator.
Symptoms of a malfunction of the electronic sensor
If an error appears on the display or the temperature indicator flashes, and the refrigerator does not freeze or, conversely, works without stopping, the sensor has probably failed. In Bosch models, an error in the evaporator sensor is often encountered, which leads to failures in the defrost cycle and continuous operation of the compressor.
Refrigerant leakage and clogged capillary system
If the refrigerator Bosch hums, but does not freeze and does not turn off, there is a high probability of circulation problems refrigerant (freon). A microscopic clogging gas could have formed or occurred in the system. In both cases, the pressure in the system drops or is disrupted, and the compressor tries to compensate for this by continuous operation. leak gas In both cases, the pressure in the system drops or is disrupted, and the compressor tries to compensate for this by continuous operation.
When freon leaks, the amount of refrigerant becomes insufficient for effective heat extraction. The compressor circulates the remaining gas in a circle, but the temperature in the chambers does not drop to the required level. A characteristic sign of a leak is a hot condenser (rear grille or side walls) and a lack of cold when the engine is running.
Clogging of the capillary tube often occurs due to moisture entering the system or oil breakdown products. An ice plug forms at the site of the blockage, blocking the flow of freon. In this case, the compressor can become very hot, trying to push through the plug, while the evaporator remains warm.
To eliminate these problems, you need to call a technician with professional equipment. It is necessary:
- 🔍 Find the leak using a leak detector.
- 🔧 Purge the system with nitrogen to remove the blockage.
- ⚖️ Fill the refrigerator with freon strictly according to the weight indicated on the nameplate.
- 🔌 Replace the filter drier (mandatory when opening the circuit).
Wear of the compressor and problems with the start relay
The compressor itself is the heart of the refrigerator. Models Bosch often use reliable inverter or linear compressors, but they do not last forever. Over time, the piston group, valves or engine windings wear out. The motor loses its performance (compression) and physically cannot create the required pressure for cooling, so it works without interruption.
Another element that affects the start and operation of the motor is start relay. This device provides the initial push to start the engine. If the relay is faulty, it may not open the start winding circuit, causing the compressor to hum but not start, or to operate under overload.
| Symptom | Probable cause | Actions |
|---|---|---|
| The compressor hums, but does not start | The motor is jammed or the starting relay is faulty | Replacing the relay, checking the windings |
| The motor runs quietly, but not cold | Valve wear, loss of compression | Replacing the compressor |
| Severe knocking and vibration | Destruction of the compressor suspension | Suspension repair or replacement |
| Periodic clicking | Faulty start relay | Relay diagnostics |
If you hear that the compressor is running with an unusual sound, or it has become noticeably hotter than usual (over 90°C), this is a sure sign of wear and tear. Operation in this mode may result in a short circuit.
Failures in the electronic control module
In refrigerators Bosch with the system MultiAirflow and electronically controlled, the main module is responsible for all processes. This is a complex board with a microprocessor that reads sensor readings and controls the compressor, fans and defrost heating elements. If the compressor control triac on the board burns out or a software failure occurs, the engine may go into constant operation mode.
Often the cause is a power surge in the network. Even if the board looks intact on the outside, the chips could be damaged. In such cases, the refrigerator may behave inappropriately: freeze to -30°C in the refrigerator compartment or, conversely, not turn off at the right temperature.
Diagnostics of the module at home is difficult. You can try to perform reset settings (Hard Reset). To do this, you need to disconnect the refrigerator from the power supply for 15-20 minutes, and then turn it on again. If the problem was a software glitch, this may help.
If resetting does not help, you will need professional diagnostics of the board using an oscilloscope and checking the output signals to the compressor. Repairing a module is often more economically feasible than replacing the entire unit.
Influence of the external environment and operating conditions
Do not forget about external factors. A refrigerator Bosch is a technically complex device that is sensitive to environmental conditions. If the unit is installed next to a radiator, stove, or in direct sunlight, the heat transfer efficiency drops sharply.
The rear wall of the refrigerator (condenser) should be freely washed by air. If the distance to the wall is less than 5-7 cm, or if dust and animal hair have accumulated behind, the heat does not escape into the atmosphere, but returns back to the system. The compressor is forced to work longer to compensate for poor heat transfer.
⚠️ Attention: Do not install the refrigerator in a niche without a top ventilation grille. Impaired air circulation is a common cause of overheating and continuous operation of Bosch appliances in kitchen units.
It is also important to consider the climate class of the device. If a refrigerator designed for a temperate climate (SN, N) is placed in an unheated room in winter or in a kitchen where it is +35°C in summer, it will work with overload or refuse to turn on.
Frequently asked questions (FAQ)
Why does the new Bosch refrigerator not turn off on the first day?
This is normal. After first switching on or long-term transportation, the refrigerator requires time (from 4 to 24 hours) to cool the entire internal volume, walls and food to the set temperature. During this period, the compressor can operate without interruption. If the mode does not return to normal after a day, this is a cause for concern.
Can the "Super Freeze" mode cause non-stop operation?
Yes, if the Bosch refrigerator has the SuperFrost (Super Freeze) function activated, the compressor will work continuously until you manually turn off this mode or until the programmed time has passed (usually up to 50 hours). Check the control panel and disable the function if it is not needed.
Is it dangerous to continue to operate a refrigerator that does not turn off?
Short-term operation (several hours in hot weather) is acceptable. However, long-term operation without stopping (a day or more) leads to overheating of the compressor windings, oil degradation and eventual engine seizure. This can lead to costly repairs or a fire hazard.
How often do you need to defrost a Bosch NoFrost refrigerator?
The system NoFrost does not require manual defrosting to remove ice, as this happens automatically. However, it is recommended to completely defrost and wash the refrigerator at least once a year for hygiene and to check the condition of the seals. The accumulation of dirt in the drainage system can cause malfunctions.