The situation when the refrigerator works without interruptionis familiar to many owners of household appliances. The hum of the compressor, which does not subside day or night, is often the first signal that a failure has occurred in the cooling system. Ignoring this problem can lead to food spoilage, increased energy consumption and, ultimately, costly repairs or complete replacement of the unit. Understanding the reasons for the continuous operation of the motor is the first step to saving your equipment.
Modern models, be it Indesit, Atlant or LG, are equipped with complex electronics, which should automatically adjust the on and off cycles. However, if the temperature regime is violated or the sensors fail, the system stops receiving a signal that the desired temperature inside the chambers has been reached. As a result, the compressor tries to compensate for the heat, working for wear. It is important not to panic, but to consistently analyze the condition of the device in order to identify the source of the malfunction.
In this article we will analyze in detail the mechanical and electrical causes of the breakdown, consider the diagnostic features of various components and determine when you can cope on your own and when you need to call a specialist. It is critically important to understand that operating a compressor for more than 24 hours without stopping at maximum load can destroy it in a matter of days due to overheating of the windings. Let's figure out why the equipment behaves incorrectly and how to return it to normal operation.
Violation of the tightness of the chambers and wear of the seal
One of the most common and easily eliminated reasons for the continuous operation of the refrigerator is a violation tightness of the internal circuit. If warm air from the room constantly enters the chamber, sensors detect an increase in temperature and command the compressor to work more intensely. Often the culprit is sealing rubber on the door, which over time dries out, cracks, or simply becomes dirty. A visual inspection may not reveal a defect, so a more thorough check is required.
To diagnose the tightness of the door, use a simple test with a sheet of paper. Clamp the sheet between the door and the refrigerator body in different places around the perimeter. If the paper is removed freely, without resistance, it means that the seal is broken in this place. It is also worth checking whether the door itself is warped due to improper installation or overloading of the shelves. Even a small gap of a few millimeters creates a constant flow of heat, causing the motor to operate in emergency mode.
⚠️ Attention: If the seal is simply contaminated with grease or crumbs, it can be washed with warm water and soap. However, if the rubber has cracked or lost its elasticity, restoring its properties using traditional methods (for example, heating it with a hairdryer) can only be temporary - a complete replacement of the element will be required.
Another factor affecting the tightness is the condition of the chambers themselves. Microcracks in the plastic or damage to the inner coating can allow heat to pass through, although this is less common. Make sure that the door closes tightly and clicks, and that food does not interfere with the normal closing of the doors. Sometimes it is enough to simply correct a plate that is stuck in the guide to restore normal operation.
Incorrect temperature setting
Often the cause of the “malfunction” lies in a simple user error or settings failure. If you accidentally set the mode super freezes or set the minimum possible temperature in the main chamber, the refrigerator will work continuously, trying to reach unattainable values. In modern models with electronic control No Frost one wrong press is enough to reset the settings.
Check the readings on the display or the position of the regulator inside the chamber. For normal storage of food, a temperature of +2 to +5 degrees Celsius in the refrigerator compartment and -18 degrees in the freezer is sufficient. Setting lower values has no practical meaning, but causes the compressor to run non-stop. Reset the settings to factory settings or set the recommended values manually.
- 🌡️ Checking the thermostat: Make sure that the mechanical regulator knob is not turned to the maximum, and the electronic sensor does not show erroneous values.
- ❄️ Quick freezing mode: Disable the "Super Freeze" function if it is activated, as it is intended for short-term operation.
- 🔌 Reboot the system: Try to disconnect the device from the network for 10-15 minutes to reset temporary controller errors.
It is also worth considering external factors. If the refrigerator is located next to a radiator, in direct sunlight or in a niche with poor ventilation, it is physically difficult for it to give off heat. In such conditions, even the correct temperature regime will not help - the unit will work at its limit. Provide a gap of 5-10 cm between the back wall of the appliance and the wall of the room for normal air circulation.
Malfunctions of the thermostat and temperature sensors
If everything is in order with the tightness and settings, the problem may lie in the "brains" of the system - thermostat or defrost sensors. The thermostat is responsible for opening the compressor power circuit when the set temperature is reached. If its contacts are “stuck” in the closed position or the sensing tube is broken, the signal to turn off the motor simply will not come. In refrigerators with a system No Frost an electronic module is responsible for this process, receiving data from several sensors.
Diagnostics of a mechanical thermostat is possible at home with a multimeter. It is necessary to remove the casing, disconnect the wires and ring the contacts. When the temperature of the sensitive element changes (it can be cooled, for example, by putting it in the freezer for a short time), a click should occur and the circuit should break. If there is no click or resistance does not change, the part must be replaced. This is a consumable material that is inexpensive and changes quite quickly.
| Type of fault | Symptoms | Test method | Difficulty of repair |
|---|---|---|---|
| Sticking contacts | The compressor is humming, does not turn off | Check with a multimeter | Low |
| Freon leaking from the tube | The refrigerator does not freeze, the motor is running | Visual inspection of the tube, leak test | High |
| Electronics failure | Incorrect readings on the display | Controller diagnostics | Average |
| Open sensor circuit | Error on the display, constant operation | Sensor resistance measurement | Average |
Models with electronic control often fail air temperature sensors or evaporator defrost sensors. If the defrost sensor “lies” and shows that there is no ice on the evaporator when there is, or vice versa, the system may not start the defrost cycle or, conversely, prevent the compressor from starting (although in our case it works constantly). The resistance of these elements is checked using resistance tables for a specific model.
How to check a thermostat without a multimeter?
There is a popular method: if when you turn the control knob to the "Off" position the compressor does not stop, most likely the thermostat is faulty. However, this method is not 100% guaranteed and requires caution.
Refrigerant leakage and compressor problems
A more serious reason for continuous operation is freon leak from the system. When the amount of refrigerant decreases, the pressure in the circuit drops and the compressor cannot reach the required temperature. It works constantly, trying to compensate for the lack of working fluid, but the cold is not produced in the required volume. It is difficult to determine a leak visually; it often manifests itself in the form of swelling of the refrigerator wall or oily spots (oily traces) at the joints of the tubes.
Another critical problem is the wear of the compressor itself. Over time, the piston group wears out, the valves lose their tightness, and the engine ceases to create sufficient pressure. In this case, it may hum, but not pump freon effectively. Working in this mode is extremely dangerous: the motor windings overheat, and the entire unit may need to be replaced. If you hear unusual knocking or metallic clanging noises when the engine is running, this is an alarming signal.
⚠️ Attention: Self-filling the refrigerator with freon is prohibited without a license and special equipment. This is not only technically difficult (evacuation of the system is required), but also dangerous to health. If you suspect a leak, call a technician.
Sometimes the problem lies in a clogged capillary tube. If a plug from oil or moisture breakdown products occurs in the refrigerant circulation system, freon cannot circulate normally. The pressure at the compressor outlet increases and the pressure at the inlet decreases, which leads to continuous operation of the motor without reaching cold. Cleaning the system is a complex procedure that requires purging with nitrogen and replacing the filter-drier.
Failures in the defrost system (for No Frost refrigerators)
In refrigerators with a system No Frost, continuous operation of the compressor is often associated with problems with evaporator defrosting. If the defrost heating element, timer or defrost sensor is faulty, a “coat” of ice will build up on the evaporator. This ice blocks the circulation of cold air, and the sensors in the chambers do not detect the decrease in temperature, causing the compressor to work without stopping. At the same time, it may be warm in the chambers, and behind, behind the plastic panel, there is a huge lump of ice.
To test this hypothesis, it is often enough to defrost the refrigerator completely. Unplug the device for 24 hours (this is how long it takes for the ice to melt in hard-to-reach places). If, after turning on, the refrigerator started working in a normal cycle (turns on and off), then the problem was ice freezing. However, this is a temporary solution - a faulty element of the defrost system (heating element, sensor or control module) will have to be replaced.
- 💧 Checking the drain hole: Make sure that the drain hole is not clogged with debris, otherwise the water will freeze and block the operation of the system.
- 🔥 Heating element diagnostics: Ring the defrost heating element - it should have a resistance of several hundred ohms. An open circuit will indicate the need for replacement.
- ⏱️ Defrost timer: In older models, the mechanical timer could get stuck in the "cooling" position without switching to defrost mode.
It is important to understand that Ignoring defrosting problems can result in ice reaching the fan, causing extraneous noise, or even damaging the plastic parts of the chamber. Therefore, if complete defrosting helped only for a short time, look for the electrical cause of the malfunction in the defrost circuit.
☑️ Diagnostics of the No Frost system
Influence of external factors and operating conditions
Do not reset from accounts and external operating conditions of the equipment. A refrigerator is a heat pump that transfers heat from inside to outside. If the room is too hot (above +30...+35 degrees Celsius), the efficiency of heat transfer drops sharply. The condenser (black grille at the back) does not have time to cool down, and the refrigerator works almost without interruption, trying to maintain the cold. This may be relevant in the summer or if the equipment is standing near the stove.
The occupancy of the chambers is also important. An empty refrigerator loses cold faster when the door is opened, since the air mass is small. On the contrary, a completely clogged unit with food (especially if the food is blocking the ventilation openings) can interfere with air circulation. The optimal load is about 50-70% of the volume, maintaining the gaps between the products and the walls.
⚠️ Attention: The technical characteristics of the refrigerator are designed to operate in a certain climate class (SN, N, ST, T). Using the appliance outside the recommended room temperature range (for example, in an unheated garage in winter or in the kitchen near a hot stove) may result in continuous operation and breakdown.
In addition, frequent opening of the door or inserting hot products will directly affect the operating cycle. If you just put a pot of soup on, the compressor will run longer than usual, and that's normal. But if this happens constantly, it’s worth reconsidering your operating habits.
Frequently asked questions (FAQ)
How long should the refrigerator operate normally?
In normal operation, the operating time ratio is about 30-40%. This means that the compressor runs for approximately 15-20 minutes, followed by a pause of 30-40 minutes. The exact time depends on the model, room temperature and camera load. If the refrigerator runs for 2 hours straight and turns off for 10 minutes, this is a sign of a malfunction.
Can the refrigerator not turn off due to power surges?
Yes, power surges can damage the electronic control module or the compressor start relay. As a result, the equipment may “freeze” in constant operation mode. For protection, it is recommended to use a voltage stabilizer or surge protector, especially in houses with old wiring.
What to do if the refrigerator hums, but does not freeze and does not turn off?
This is a classic sign of a freon leak or a clogged capillary tube. The compressor tries to pump, but the refrigerant does not circulate. It is necessary to turn off the device, defrost it (if there is ice) and call a technician to look for leaks and refill it. Operation in this mode will quickly damage the motor.
Is it true that a new refrigerator should work constantly?
When turned on for the first time, a new refrigerator can work without interruption for up to 24 hours to reach the initial temperature. This is fine. However, if it does not turn off even on the second or third day, and it is not cold inside, this is a reason for concern and contacting service.
How to extend the life of a compressor with frequent power outages?
Frequent switching on and off of the power is harmful to the compressor. If the light is flashing, it is better to temporarily unplug the refrigerator. It is also useful to install a time relay or protection that will prevent the motor from starting again immediately after a power surge, giving the system time to stabilize the pressure.