Search evaporator sensor in refrigerators Liebherr often becomes a necessity when the unit stops working work correctly in NoFrostmode. Owners may experience a build-up of ice on the back wall or, conversely, food defrosting due to lack of cold. Understanding the exact location of this element is the first step to diagnosing a breakdown.
In modern models of the German brand, temperature sensors are built directly into the evaporator design or located in close proximity to it. This ensures the most precise control of heat transfer. However, access to them is blocked by several layers of insulation and decorative panels, which requires careful disassembly.
Before you begin (disassembly), you must clearly understand the structure of your model. In some cases temperature sensor it may be hidden behind plastic plugs that can be easily damaged by careless movement. Therefore, be patient and have a suitable tool.
The role of the temperature sensor in the NoFrost system
The main function defrost sensor is to transmit signals to the electronic control module. It is this small element that tells the “brains” of the refrigerator when to turn on the heating element to defrost the evaporator and when to turn off the heating. If the sensor transmits incorrect data, the operating cycle is disrupted.
Refrigerators Liebherr use complex logic for the operation of the compressor and fans, based on the readings of temperature sensors. If one of the elements malfunctions, the system may go into error or operate in emergency mode. Often this manifests itself in the form of a constant hum or, conversely, complete silence of the unit.
It is worth noting that in two-chamber models, sensors can be installed both in the freezer compartment and in the refrigerator compartment. Their tasks differ: some control the air temperature, others control the degree of icing heat exchanger.
The exact location of the sensor in different models
The answer to the question where located evaporator sensor, depends on the series of the refrigerator Liebherr. In classic models with a NoFrost system, the sensor is usually pressed into the aluminum tube of the evaporator or fixed to its surface using a special clamp. You can get to it only by removing the back panel of the freezer.
In models with technology DuoCooling or VarioZone the arrangement of elements may be more complex. Here, sensors are often built into the air ducts. For their visual inspection, it is necessary to dismantle not only the back wall, but also parfois (sometimes) side panels or even the entire internal circuit.
- 📍 Freezer compartment: The sensor is located behind the rear plastic panel, directly on the evaporator fins.
- 📍 Refrigeration compartment: In some models, the sensor is hidden in the ceiling of the chamber or in the cold air supply channel.
- 📍 Freshness zone: Individual sensors can control the temperature in the drawers BioFresh, located under the bottom of the drawers.
⚠️ Attention: In models with a double cooling circuit, access to the freezer sensor may be blocked by the control unit. Do not try to forcefully bend the plastic - it becomes brittle in the cold.
If you are looking thermistor in built-in appliances, keep in mind that access to the back wall may be limited by the furniture box. Before starting work, make sure that you have room to maneuver.
Instructions for accessing the evaporator sensor
The search and dismantling process temperature sensor requires sequential steps. Violation of the disassembly procedure can lead to damage to the plastic fasteners or freon pipes.
First you need to completely defrost the refrigerator. Even if you think there is not enough ice, moisture inside the insulation can cause a short circuit or damage the electronics when turned on. Leave the unit turned off for at least 12 hours.
☑️ Preparation for disassembly
After defrosting, remove all attachments inside the freezer. Then carefully remove the screws securing the back panel. In refrigerators Liebherr they are often hidden under decorative plugs or located inside the ventilation holes.
When the panel is removed, you will see the evaporator. Sensor it is a small plastic cylinder or tablet from which two wires come. It can be fixed in a special socket on the tube or simply pressed against it with a metal bracket.
Difficulties in removing the panel
If the back panel cannot be removed, do not use force. Check to see if you forgot to remove the air duct or door sensor, which could block removal. Sometimes you need to heat the plastic with a hairdryer to make it more elastic.
Typical signs of a sensor malfunction
You can understand that evaporator sensor has failed using indirect signs, without resorting to complex diagnostics. Most often, the refrigerator begins to behave inappropriately: it either freezes too much or stops cooling altogether.
One of the most striking symptoms is a “crying” evaporator. If after the defrost cycle the ice does not disappear completely, but builds up layer by layer, it means that the control module does not receive a signal that defrosting is complete. This is the direct fault of thermal sensor.
| Symptom | Probable cause | Actions |
|---|---|---|
| Ice coat on the evaporator | The sensor does not detect the heating of the heating element | Replacing the sensor |
| The refrigerator does not turn off | Low temperature readings | Checking the resistance |
| Frequent compressor shutdowns | Inflated sensor readings | Circuit diagnostics |
| Alarm indicator is constantly on | Open sensor circuit | Checking contacts |
It is also worth paying attention to the operation of the fan. If sensor shows critical icing, the fan can be blocked to prevent damage to the blades on the ice. As a result, the cold stops flowing into the chamber, although the compressor is working.
Diagnostics and resistance check
For accurate diagnostics temperature sensor you will need a multimeter. The resistance of a working thermistor Liebherr at room temperature (about +20°C) is usually from 4 to 6 kOhm. However, the exact values depend on the specific model and type of sensor used.
The verification process is as follows: disconnect the sensor connector from the control board or cut the wires (with a margin for connection). Connect the multimeter probes to the contacts. If the device shows infinity or zero, the part is definitely faulty.
It is important to check not only the sensor itself, but also the integrity of the wires going to it. Vibration and temperature changes often lead to microcracks in the insulation and fracture of the core inside. This may not be noticeable visually, so “ring” the entire section of the chain.
⚠️ Attention: When installing a new sensor, the connection point of the wires must be perfectly sealed. Use heat shrink and silicone sealant to prevent moisture from getting inside the contact.
Replacement and installation features of a new sensor
When replacing thermal sensor in a refrigerator Liebherr it is extremely important to use original spare parts or high-quality analogues with identical characteristics. A difference in resistance of even a few percent can lead to incorrect operation of the entire system NoFrost.
Installation is carried out in the reverse order. Make sure the new sensor fits snugly against the surface of the evaporator. If the design involves the use of heat-conducting paste, apply it in a thin layer to improve heat transfer.
After assembly and switching on, check the operation of the unit in test mode. If your model has a self-test function, run it. The absence of errors and the correct defrosting cycle will confirm the success of the repair.
Is it possible to temporarily do without a sensor?
Theoretically, by short-circuiting the circuit or installing a resistor of a certain nominal value, you can make the refrigerator work. However, this will lead to uncontrolled operation of the compressor and the risk of food defrosting or the system freezing. Operation without a sensor is only possible in emergency mode for a short time.
Where to buy an original sensor for Liebherr?
Original spare parts are best ordered from authorized service centers or official dealers of the brand. There are many analogues on the market, but their parameters (B-coefficient) may not match the requirements of your refrigerator.
How long does it take to replace the sensor?
An experienced technician needs about 40-60 minutes, including defrosting. Self-replacement can take up to 3-4 hours, especially if you have to disassemble such a structure for the first time and carefully steam off frozen plastic elements.