The situation when LG refrigerator works without interruption is one of the most alarming for the owner of household appliances. This not only creates a constant background noise that can be annoying at night, but also signals serious problems with the cooling system. A compressor operating non-stop experiences enormous overloads, which in the shortest possible time can lead to its complete combustion and costly repairs.
Unlike old Soviet models, modern units of the Korean brand are equipped with complex electronics, which should automatically regulate on and off cycles. If this does not happen, it means that one of the sensors is transmitting incorrect data, or the tightness of the circuit is broken. You need to quickly diagnose the problem, since inverter compressoralthough it is highly reliable, it is extremely sensitive to overheating and voltage surges during long-term operation.
In this article we will analyze in detail all the possible reasons why the unit does not go into rest modeand compile step-by-step action plan. We will consider both simple operating errors that can be corrected on your own in five minutes, as well as complex technical malfunctions that require the intervention of professionals.
The influence of external temperature and the Super Freeze mode
The most banal, but often ignored reason for continuous operation lies in environmental conditions. If you install the refrigerator in a room where the air temperature exceeds +32°C, or there is a powerful stove next to it, the cooling system simply does not have time to reach the desired temperature. The thermostat detects that it is still warm inside and commands the compressor to continue working.
The second important factor is the activation of the intensive freezing function. On many LG models, this option is designated as Super Freeze or Quick Freeze. When turned on, the refrigerator is forced to operate at maximum power for 24–48 hours, ignoring standard temperature shutdown thresholds. This is necessary for quickly freezing a large volume of food, but if you forget the function is turned on, the unit will hum for days.
⚠️ Attention: Do not install the refrigerator close to the wall or in a niche without gaps. For effective heat exchange, the rear radiator grille requires free air flow. The minimum distance to the wall should be 5–10 cm.
Check whether the fast freezing mode is accidentally turned on. This is usually indicated by a lit indicator on the control panel or display. To disable the function, just press the corresponding button or hold it for 3 seconds, depending on the modification of your model LG DoorCooling+ or LG InstaView.
Problems with the seal and chamber tightness
If the compressor is humming, but there is not enough cold inside, there is a high probability of a chamber seal failure. The rubber seal around the perimeter of the door loses its elasticity over time, cracks or deforms. Through the resulting cracks, warm air enters inside, which the temperature sensors perceive as a signal to start active cooling.
You can check the tightness in a simple way: hold a sheet of paper between the door and the body of the refrigerator and try to pull it out. If the paper comes out easily and without resistance, it means that the seal does not fit in this place. It is also worth carefully inspecting the rubber for cracks, adhering debris or greasy deposits that interfere with a tight fit.
Often the problem is solved by simply cleaning or restoring the shape of the seal. You can try warming up the deformed areas with a hairdryer (be careful not to overheat the rubber) and straighten them by pressing the door for several hours. If the rubber is very worn, it will be required replacing the seal, since gluing in this case will not give a long-term effect.
Malfunctions of the thermostat and temperature sensors
In modern LG models, it is not mechanical thermostats that are responsible for temperature control, as in older models, but electronic sensors (thermistors). They are located in different areas: in the freezer, in the main compartment and sometimes in the freshness area. If one of these elements fails or begins to “lie,” the control board receives erroneous data.
For example, if the sensor in the freezer “thinks” that it is only -5°C instead of the required -18°C, it will constantly send a signal to turn on the compressor. Visually it looks like this: the refrigerator works without stopping, the food in the freezer may even freeze, and in the main chamber the temperature will be close to normal or slightly higher.
Diagnostics of electronic sensors at home is difficult, since it requires testing with a multimeter at different temperatures. However, if you notice flashing indicators or error codes on the display (for example, Er:FF, Er:SF), this is a direct indication of a problem with the sensor. In this case, it is necessary to replace the failed element with an original one.
Where are the sensors?
In most LG models, the main refrigerator compartment sensor is located on the back wall inside, often hidden by a plastic cover. The freezer sensor is located in the evaporator area.
Refrigerant leakage: a hidden threat
One of the most serious reasons why the refrigerator does not turn offis a freon leak. The refrigerant circulates in a closed circuit, but over time, microcracks may form in solder areas or in a factory seam. The gas evaporates, it becomes insufficient for effective heat extraction, and the compressor is forced to work continuously, trying to compensate for the lack of cooling capacity.
Indirect signs of a leak are:
- ❄️ Insufficient cooling of products in all chambers, despite round-the-clock operation motor.
- 🔥 Strong heating of the compressor (it can be hot to the touch, almost burn).
- 🧊 The appearance of swelling on the side walls of the refrigerator (in the place where the pipeline is baked).
- 🔇 Complete absence of the characteristic sound of liquid flowing in the tubes after shutdown (if it ever occurs).
It is impossible to eliminate the leak yourself. You need to call a technician who will pressure test the system with nitrogen, find the location of the damage, seal it and fill the refrigerator with a new portion of freon. Operating the unit with a leak will lead to rapid failure of the compressor.
Clogged capillary tube and filter drier
The capillary tube and filter drier play an important role in the refrigerant circulation system. The filter retains moisture and oxidation products, but over time it can become clogged. If this happens, the patency of the tube is disrupted and freon cannot circulate normally through the system. The pressure in the circuit drops, the sensors record the absence of cold, and the motor works without rest.
Symptoms of a blockage are often similar to a leak, but there is a nuance: if blocked, the compressor can work very quietly or, conversely, overload, and the condenser (grid at the back) will be only partially hot - usually in the upper part, while the bottom will remain cold.
To eliminate this problem you need:
- 🛠️ Pumping out old freon from the system.
- 🔄 Replacing the filter-drier (this is a disposable element).
- 💨 Blowing the capillary tube with nitrogen under high pressure.
- ⛽ Evacuate the system and refill with refrigerant.
☑️ Diagnostics before calling a technician
Faults in the control module and start relay
The electronic “brain” of the refrigerator - the control module - may malfunction. If a resistor on the board burns out or the tracks short out, the control signal may “stick” in the “ON” position. In this case, the compressor receives power constantly, regardless of the temperature sensor readings.
It is also worth paying attention to the start relay, especially in models with conventional (non-inverter) compressors. If the relay contacts are stuck in the closed position, the motor windings will be constantly energized. This is fraught not only with continuous operation, but also with a fire hazard.
In models with Linear Inverter Compressor the situation is more complicated. There is no classic relay here, and the start is controlled by the inverter board. If it fails, the compressor may not start at all or may operate in emergency mode. Diagnostics of the board requires special knowledge and equipment.
Table: Comparison of symptoms of various faults
To make it easier for you to navigate a possible breakdown, we have compiled a summary table of symptoms. Pay attention to the combination of factors.
| Malfunction | Compressor operation | Internal temperature | Housing/pipes heating | Sounds |
|---|---|---|---|---|
| Freon leak | Constantly, without stopping | Above normal (warm) | Compressor is very hot | Silence (no gurgling) |
| System clogged | Continuous or cyclical | Uneven | Only the top of the condenser is hot | May be quieter than usual |
| Fault sensor | Continuously | May be normal or freezing | Standard heating | Normal hum |
| Bad seal | Frequent switching on, long work | Above normal | Normal | Normal hum |
| Super Freeze mode | Constantly (up to 48 hours) | Very low (in the freezer) | Strong heating | Intensified hum |
Specifics of LG inverter compressors
Owners of LG refrigerators with technology Linear Inverter it is important to understand one feature: their compressors often do not turn off completely. Unlike traditional models that operate jerkily (turned on - worked - turned off), the inverter motor can simply reduce the speed to a minimum, maintaining the temperature.
This is a normal operating mode that ensures energy saving and silence. If you hear a quiet hum even at night, but the food is frozen or cooled efficiently, and there are no errors on the display, most likely everything is fine with your refrigerator. It simply went into temperature maintenance mode.
However, if you notice that the unit is starting to operate louder than usual, vibrates, or consumes significantly more electricity, this is a cause for concern. Inverter boards are sensitive to power surges in the network.
⚠️ Attention: Technical characteristics and operating algorithms of the electronics may vary depending on the specific series and year of manufacture. If you are not sure about the normal behavior of your model, check the official user manual or contact an authorized LG service center.
How to distinguish normal operation of the inverter from a breakdown?
Normal operation: quiet, smooth hum, no sharp clicks, stable temperature. Failure: loud knocking, vibration, errors on the display, lack of cold.
Frequently asked questions (FAQ)
Can an LG refrigerator not turn off due to the heat outside?
Yes, if the temperature in the room where the refrigerator is located rises higher +32...+35°C, the system may not cope with the heat inflow. The compressor will work almost without interruption, trying to maintain the set temperature inside the chambers. In such conditions, it is recommended to provide additional ventilation or move the equipment to a cooler place.
What to do if the refrigerator does not turn off after defrosting?
After complete defrosting (especially if it lasted more than a day), the refrigerator takes time to return to operating mode - usually from 2 to 6 hours. During this time, it can work continuously. If after 10–12 hours of intensive work the temperature has not stabilized, the tubes may have been damaged during defrosting or the electronics may have failed.
Is it dangerous to leave a refrigerator running non-stop on?
Yes, it is dangerous. Long-term operation without breaks leads to overheating of the compressor windings, drying out of the oil and destruction of rubbing parts. Ultimately, this threatens to jam the motor and burn it out, which is one of the most expensive breakdowns. In addition, overheating can damage the insulation of the wiring.
Why does the new LG refrigerator work without interruption on the first day?
When you turn it on for the first time or after long-term transportation, the refrigerator takes time to cool the entire internal volume and the food that you put in it. In the first 12–24 hours, continuous operation of the compressor is considered normal. Do not completely load the chamber with food at once - let the equipment reach an empty temperature.
How to reset the error if the refrigerator is humming due to an electronics failure?
Try to perform a full reset of the system. To do this, disconnect the refrigerator from the electrical network by removing the plug from the socket. Leave it unplugged for 15–20 minutes. This will allow the control board to completely discharge and reboot. After turning it on, check if the problem has been resolved.