The situation when the refrigerator works without interruptioncan take any owner of household appliances by surprise. Usually we are accustomed to the rhythmic hum of the engine, which is replaced by silence, but if the unit hums for days on end, this is the first signal of a malfunction. Ignoring such a problem often leads to critical consequences, including failure of expensive components.
In modern models, such as Bosch or Liebherr, the control system itself regulates the on and off cycles. If this does not happen, it means that the operating logic is broken thermostat or a refrigerant leak has occurred. It is important not to panic, but to consistently analyze the operating conditions and technical condition of the device.
Constant operation of the compressor is not only extra kilowatts in the electricity bill, but also a direct path to engine overheating. With continuous operation for more than 24 hours, the life of the compressor is reduced significantly, which often leads to its complete combustion. Understanding the reasons will help you react quickly and, perhaps, avoid costly repair.
Heat overload and violation of operating conditions
Before sounding the alarm and looking for a breakdown inside the housing, it is worth assessing external factors. Often the reason is simple: too much heat gets into the refrigerator compartment. This can happen if you put a hot pot of soup inside or leave the door ajar for a long time. In such cases thermostat it simply cannot register the achievement of the desired temperature.
It is also worth checking the tightness of the fit sealing rubber along the perimeter of the door. If it is contaminated with food debris, deformed or dried out over time, cold air will evaporate and warm air will flow inside. The unit will try to compensate for heat loss by operating in an enhanced mode.
- 🔥 You put hot or warm foods in the chamber without first cooling them.
- 🚪 The refrigerator door is not fully closed or is skewed due to uneven floor.
- 🌡️ The device is installed close to the wall or next to a heat source (battery, stove).
Pay special attention to the location of the equipment. If there is no gap for ventilation at the back where condenseris located, heat will not be dissipated effectively. In the summer, when the room is hot, the load on the cooling system naturally increases.
Faults in the thermostat and temperature sensors
One of the most common reasons for continuous operation is failure thermostat (in mechanical models) or temperature sensor (in models with electronic control No Frost). This element is responsible for reading the temperature inside the chambers and sending a signal to turn off the compressor. If the sensor “lies” and shows that the chamber is still warm, the motor will work endlessly.
In mechanical refrigerators, the thermostat is a device with a bellows filled with freon. Over time, gas can evaporate through microcracks, and the contacts simply stop opening. In electronic models Samsung or LG the problem may lie in oxidation of the sensor contacts or broken wiring.
⚠️ Attention: Trying to replace the thermostat yourself requires accurate diagnostics. Incorrect calibration of the new sensor will result in food either freezing or starting to spoil.
Diagnostics of this unit is usually carried out using a multimeter. It is necessary to “ring” the contacts at different temperatures. If the circuit does not open when the sensor is cooled (for example, in a freezer), the part must be replaced. This is a standard procedure do-it-yourself repair for those who are handy with tools.
Freon leakage and problems with the cooling system
The most unpleasant and technically difficult reason is refrigerant leak (freon). If a microcrack has formed in the circuit, the gas gradually escapes. The compressor continues to work, trying to build up pressure and cool the chamber, but due to a lack of working fluid, efficiency drops to zero. As a result, we see a running motor and warm products.
It is difficult to determine a leak visually, but there are indirect signs. In models No Frost ice may begin to intensively freeze on the back wall of the evaporator, forming a characteristic “fur coat” in one place. In conventional models, the condenser (grid at the back) can be only partially cold or warm.
Restoring the system in this case is a task for professionals. Required:
- 🔍 Find the location of the leak using a leak detector or by immersion in water (for removed components).
- 🔧 Solder the copper tubes and restore the circuit.
- ❄️ Evacuate the system and fill with new freon strictly according to weight.
Using a refrigerator with a freon leak is dangerous because the compressor runs “idle” and without proper cooling, which is provided by the circulating gas. This is guaranteed to lead to its overheating and jamming.
Is it possible to add freon yourself?
Self-refueling without vacuuming the system is prohibited. The air and moisture remaining in the tubes form acid, which in a few weeks will “eat” the compressor from the inside.
Wear of the compressor and problems with the start relay
The heart of the refrigerator is compressor. Over time, its mechanical parts wear out, the piston group loses its tightness, and performance drops. The motor hums and vibrates, but does not create the necessary pressure in the system. As a result, the refrigerator does not turn off, since it cannot reach the set temperature parameters.
It is also worth paying attention to starting relay. This small element is responsible for starting the engine. If its contacts are burnt or the mechanism is stuck, the compressor may hum but not start, or work intermittently. In some cases, the relay can “keep” the circuit closed, not allowing the motor to rest.
Symptoms of compressor wear are often accompanied by:
- 🔊 Uncharacteristically loud knocking or metallic clanging during operation.
- 🌡️ Strong heating of the compressor housing itself (to the point where you cannot touch it with your hand).
- ⚡ A sharp jump in electricity consumption.
If you hear the motor trying to start, clicking and immediately stalling, this is a sign of a problem with the starting device or the motor windings. Operating equipment in this mode is unacceptable.
Comparison of symptoms: Diagnostic table
To make it easier to understand what exactly happened to your unit, compare the symptoms in the table below. This will help narrow down the troubleshooting before calling a technician.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| The refrigerator hums, but does not cool | Freon leak or capillary blockage | High (requires a technician) |
| The motor runs constantly, there is cold | The thermostat or sensor is faulty | Medium (you can yourself) |
| A click is heard, the engine does not start | The starting relay or compressor has burned out | Medium/High |
| Ice on the back wall, work without stopping | Defrost system malfunction (No Frost) | Average |
This table is for reference only. An accurate diagnosis can only be made by a specialist with diagnostic equipment. You should not ignore the slightest changes in the sound of operation or temperature.
Errors in the defrost system (for No Frost models)
In refrigerators with the system No Frost a complex mechanism is responsible for the removal of cold and moisture. If defrost heating element, timer or evaporator fail, an ice coat builds up on the evaporator. It blocks the air circulation, and the sensors record the high temperature in the chamber, forcing the compressor to work continuously.
Often the problem lies in the burnout of the heating element defrost. The ice does not melt, the air channels are blocked, and the cold stops flowing into the main chamber, although it can be very cold in the freezer. This can be seen visually if you remove the back panel in the freezer compartment.
It is also worth checking defrost sensor. If it is “stuck” in the “defrost in progress” or “cooling in progress” position, the cycle is disrupted. In some models Indesit or Atlant the electronic control boardmay fail, especially if there were power surges in the network.
⚠️ Attention: Defrosting a refrigerator with a No Frost system “manually” (by turning it off for a day) can temporarily solve the problem, but will not eliminate the cause. Ice will grow again in 1-2 weeks.
Prevention and proper operation
To extend the life of the compressor and avoid situations where the refrigerator does not turn offit is important to follow the operating rules. Regularly, at least once every six months, defrost the device (if it is not No Frost) and wash the drainage holes. Keep the back of the condenser clean: dust and animal hair act as a heat insulator, interfering with cooling.
Check the condition of the seals. Wipe them with warm water and soap, and then lubricate them with silicone lubricant to prevent the rubber from drying out. If the door does not close tightly, no equipment will be able to maintain the temperature effectively.
☑️ Monthly check of the refrigerator
Do not overload the shelves with products. Cold air should circulate freely inside the chambers. If you jam the refrigerator full, the sensors will show incorrect data, and the compressor will work to wear out.
FAQ: Frequently asked questions
How long can the refrigerator operate without interruption normally?
In normal mode, the refrigerator operates cyclically. Working time is about 30-40% of the total time (working time ratio). That is, he can work for 10-15 minutes and then rest for 20-30 minutes. Working without stopping for more than 2-3 hours in a row is already a sign of a malfunction or extreme conditions (for example, it is very hot in the room).
Is it dangerous to leave a running refrigerator unattended?
Yes, it is dangerous. If the compressor runs continuously, it becomes very hot. In the worst case, the insulation of the wires may melt, a short circuit or even a fire may occur. In addition, you risk being left without food and having to buy new equipment.
Why does a new refrigerator not turn off for a long time after the first turn on?
When starting for the first time or after a long defrosting, the refrigerator needs time to cool the entire volume of chambers and food to the set temperature. This process can take from 3 to 12 hours. During this period, continuous operation of the compressor is the norm, not a breakdown.
Is it possible to repair the thermostat with your own hands?
The mechanical thermostat cannot be repaired, it can only be replaced. Electronic sensors are also replaced with new ones. Self-adjustment is only possible in some models of mechanical thermostats, where there is an adjusting screw under the seal, but without experience it is better not to go there.
What to do if the refrigerator hums, but does not cool?
Most likely, there is a freon leak or the compressor has lost performance. You need to turn off the device from the network, defrost it (if there is ice) and call a technician for diagnostics. It is pointless to refill freon on your own without looking for a leak.