Modern units of the German brand Liebherr are famous for their reliability and durability, but even the highest quality equipment can malfunction. One of the most alarming symptoms that owners encounter is the continuous operation of the compressor. If you notice that your refrigerator is humming without a break, and the temperature inside the chambers is either too low or, conversely, insufficient, this is a signal of a serious malfunction.
It is absolutely impossible to ignore such a problem, since the continuous operation of the motor-compressor leads to its overheating and rapid failure, which will require an expensive replacement. In this article we will analyze in detail the main reasons why The Liebherr refrigerator does not turn offand consider the algorithm of actions for self-diagnosis and troubleshooting.
Analysis of the compressor operation and temperature conditions
First of all, you need to understand the nature of the work refrigeration unit. In normal mode, the compressor turns on and off cyclically, maintaining the set temperature. If the motor runs continuously, this means that the control system receives a signal that the required cooling capacity has not yet been achieved.
Often the reason is a simple overload of the chambers with fresh products or a violation of operating rules. However, if you are sure that the mode of use has not changed, you should pay attention to technical parameters the operation of the device. A continuous hum may be accompanied by strong heating of the side walls or the condenser grille at the rear.
⚠️ Attention: Long-term operation of the compressor for wear can lead to depressurization of the system or burnout of the motor winding, so diagnostics should begin at the first sign of an anomaly.
It is important to distinguish between situations when the refrigerator simply takes a long time to gain temperature after defrosting or loading, and when it is really “stuck” in operating mode. For accurate diagnosis, you will need temperature monitoring for several hours.
Faults of the thermostat and temperature sensors
One of the most common reasons why Liebherr does not go into rest mode is the failure of the thermostat (thermostat) or electronic temperature sensors. It is these elements that are responsible for transmitting a signal to the control module that the specified parameters have been achieved.
In older models with mechanical control, a capillary thermostat is used. Over time, its sensitive element loses its properties, the contacts stick in the “on” position, and the compressor continues to work, even when there is already “polar cold” in the chamber. In modern models with a system NoFrost and electronic control, air sensors are responsible for this.
- 🌡️ Contact sticking: mechanical damage or oxidation of the contacts inside the thermostat prevents the circuit from opening.
- 📉 Displacement of the sensing element: the capillary tube could have moved and is not in contact with evaporator properly.
- 🔌 Wiring break: damage to the cable going to the sensor leads to the transmission of incorrect data to the control board.
To check the mechanical thermostat, it often has to be removed and “ring” with a multimeter, changing the temperature of its sensitive element. Electronic sensors are checked by measuring their resistance, which should change depending on the temperature.
Problems with rubber seals and heat transfer
If the compressor works without stopping, but the temperature inside the chambers does not drop to the required values, or, conversely, the products freeze at the wall, the problem may lie in a violation of the tightness of the refrigeration circuit. Warm air from the room constantly flows inside, and the unit tries to compensate for the heat gain, operating at maximum.
The main element that ensures tightness is sealing rubber band doors. Over time, it dries out, cracks, or simply becomes dirty, causing the door to not fit tightly. Also, the cause may be a misalignment of the door or loosening of the hinges, which often occurs after long-term use or careless transportation.
You can check the tightness using a simple method: clamp a sheet of paper between the door and the body in different places around the perimeter. If the paper comes out easily without resistance, it means that the seal does not fit in this place. You can also use a flashlight turned on inside a closed refrigerator in a dark room - any gaps will be immediately visible.
| Symptom | Possible cause | Check method |
|---|---|---|
| Ice crust at the back wall | Loose door fit | Visual inspection, test with paper |
| Compressor is hot, no cold | Freon leak | Measuring pressure in the system |
| Frost throughout the entire perimeter | Faulty defrost sensor | Electronics diagnostics |
☑️ Diagnosis of tightness
Refrigerant leakage and blockage systems
A more serious technical problem, due to which Liebherr does not turn off, is a freon leak or a clogged capillary tube. In these cases, the compressor runs continuously, trying to pump up pressure or compensate for the lack of refrigerant, but the desired cooling effect does not occur.
When there is a refrigerant leak, the pressure in the system drops. The compressor is running, but the gas circulation is disrupted. Often in such cases, you can hear a characteristic gurgling or hissing sound, and the condenser (grid at the back) may be only partially warm or remain cold. Clogging of the system usually occurs due to moisture or debris getting into the circuit, which blocks the freon flow.
Repair the leak yourself or clogging without special equipment (vacuum pump, pressure gauges, freon supply) is impossible. You need to call a technician who will perform nitrogen pressure testing, find the place of damage, seal it and fill the system with new refrigerant.
⚠️ Attention: Attempts to open the copper circuit yourself or add freon “by eye” without evacuation of the system will lead to the final failure of the compressor due to the presence of moisture and air.
Why can’t you ignore the operation of the motor without stopping?
Continuous operation of the compressor when there is a freon leak leads to the motor overheating, since there is no reverse flow of gas that cools the windings. This often ends in an interturn short circuit and engine combustion.
Failure of the control board and NoFrost module
In modern refrigerators Liebherr with electronic control, all processes are controlled by the main module. If the control board receives erroneous signals or has a defect itself, it can supply constant voltage to the compressor, preventing it from stopping.
It is also worth paying attention to the system NoFrost. If the defrost timer, evaporator heating element or defrost sensor is faulty, a “coat” of ice will build up on the evaporator. This ice blocks the circulation of cold air. Sensors in the chambers record high temperatures and command the compressor to work harder, although in fact the system is clogged with ice.
- ❄️ Ice buildup: blocks the air channels, the cold does not enter the chambers.
- ⚡ Power surges: could damage the electronic components on the control board.
- 🔄 Software error: In rare cases, flashing or resetting the controller settings is required.
Electronics diagnostics require special knowledge and tools. Often an error code lights up on the refrigerator display, which can be deciphered in the instructions. For example, flashing temperature indicators may indicate a specific faulty unit.
The influence of external factors and operating conditions
The reason does not always lie within the unit itself. Sometimes the Liebherr refrigerator does not turn off due to improper operating conditions.
If the refrigerator is installed in a too hot room (for example, in the kitchen next to the stove or on the sunny side without curtains), heat transfer is disrupted. The compressor simply does not have time to cool the chambers to the required temperature and turn off, since the heat flow is too great. The same applies to installation close to the wall, which interferes with the ventilation of the condenser.
It is also worth checking the voltage in the network. At low voltage (below 190 Volts), the starting relay may not work correctly, and the engine may hum and not gain the required speed, which is perceived as continuous operation.
⚠️ Attention: Installing the refrigerator in an unheated room indoors in winter (at temperatures below +10°C) can lead to the compressor not starting at all or working intermittently, as the oil in the system thickens.
Is it possible to speed up cooling by setting the temperature to a minimum?
No, setting the regulator to maximum (Min/-) will not speed up the process, but will only make the compressor work longer without break, which is dangerous for the motor.
Frequently asked questions (FAQ)
Why does the new Liebherr refrigerator not turn off for a long time after the first turn on?
When first started, the refrigerator takes considerable time (up to 24 hours) to cool the entire volume of the chambers and enter operating mode. During this period, the compressor can work almost without interruption, which is the norm. Do not load the chambers with food on the first day.
What to do if, after defrosting, the refrigerator does not want to turn off?
After defrosting, the unit needs time to gain temperature. If it works for more than 6-8 hours without stopping and does not cool, the defrost heater or sensors may have been damaged during defrosting, or moisture has entered the system, causing an ice jam.
Can the “Super Freeze” mode cause continuous operation?
Yes, if you accidentally activated the function SuperFrost or “Quick Cooling”, the refrigerator will run continuously for the set time (usually several hours) or until you manually turn off this mode. Check the control panel.
How can you tell that the compressor has burned out and not just a faulty thermostat?
If the compressor hums but does not start, or starts for a few seconds and clicks, these are signs of problems with the start relay or the motor itself. If it works smoothly, but does not cool and does not turn off, most likely the problem is a freon leak or thermoregulation.