The situation when the refrigerator stops turning off and hums without interruption causes concern for any owner of household appliances. This is not just an annoying noise that prevents you from sleeping at night, but also a direct signal of a serious malfunction of the unit. If the compressor wears out, energy consumption increases exponentially, and the service life of the motor is rapidly reduced. Ignoring the problem can lead to complete failure of expensive equipment.
Before calling a technician or disassembling the unit, it is worth assessing the nature of the device’s operation. Sometimes the reason for constant operation is not a breakdown, but external factors: high room temperature, a door that is not tightly closed, or a temperature setting that is too low. However, if you notice that the compressor has turned on and has not turned off for several hours, and there is icing inside the chamber or, conversely, the products begin to deteriorate, it means the cooling cycle is broken. In this case, it is necessary to act quickly and consistently.
In this article we will analyze in detail all the possible reasons why the refrigerator works without interruption. We will consider both simple operating errors that can be corrected in 5 minutes, and complex technical malfunctions that require replacement of parts. Understanding the principles of operation of the refrigeration circuit will help you accurately diagnose the problem and avoid unnecessary expenses.
Checking simple causes: settings and operating conditions
Often panic occurs ahead of time, and the problem is solved by simple adjustments. First of all, check if you have the “Super Freeze” or “Quick Cool” function installed. In this mode, the compressor forced works for a long time in order to lower the temperature as quickly as possible. On modern models, such as Bosch or LG, this mode can be activated automatically when there is a large load of fresh food.
⚠️ Attention: If you have turned on the fast freezing mode, do not forget to turn it off manually after 3-5 hours, otherwise the engine may overheat.
It is also worth paying attention to the tightness of the door. If the sealing rubber is worn out, dirty or deformed, warm air constantly enters the chamber. Sensors detect the temperature increase and command the compressor to operate continuously. Check to see if any food is preventing the door from closing tightly and inspect the seal for cracks. Sometimes it is enough to wipe the rubber band with soapy water to restore the seal.
Another important factor is the temperature in the room. If the refrigerator is located next to a radiator, stove, or in direct sunlight, it is physically difficult for it to remove heat. In summer, when the temperature in the kitchen exceeds +30°C, the unit can work almost non-stop, trying to maintain the desired cold. This is a normal reaction to extreme conditions, but it is harmful to equipment.
Thermostat malfunctions: diagnostics and replacement
One of the most common reasons for continuous operation is the failure of the thermostat (thermostat). It is this sensor that is responsible for turning the compressor on and off depending on the temperature inside the chamber. If the thermostat contacts are “stuck” in the “on” position or its internal capillary tube is burned out, the signal to stop the engine simply does not arrive. As a result, the refrigerator hums until the thermal protection relay trips or the motor itself burns out.
You can diagnose a thermostat malfunction if you exclude other options. Pay attention to the temperature in the refrigerator compartment. If it is clearly cold there, food freezes, and the compressor does not think to stop - this is a sure sign of a sensor failure. In mechanical models, the problem can often be solved by replacing the regulator, which is inexpensive. In electronic systems with a display, the temperature sensor (thermistor) could fail, transmitting incorrect data to the control module.
To replace the thermostat in a mechanical refrigerator, you must:
- 🔌 Turn off the power to the unit and empty the refrigerator compartment.
- ❄️ Remove the old device by carefully disconnecting capillary tube from the evaporator.
- 🔧 Install a new thermostat with similar characteristics and markings.
How to check the thermostat with a multimeter?
To check, remove the thermostat and immerse its sensitive tube in cold water with ice. Test the contacts with a multimeter. If the circuit does not break during cooling, the part is faulty and requires replacement.
It is important to understand that incorrect installation of the thermostat can lead to incorrect operation of the entire unit. The capillary tube must fit tightly to the evaporator, otherwise the sensor will “lie” about the real temperature. If you are not confident in your abilities, it is better to entrust this operation to a professional, since a mistake costs an inexpensive repair, but can lead to damage to food.
Problems with the door seal and tightness
The tightness of the refrigeration chamber is the key to efficient operation of the compressor. If warm, moist air constantly enters through the cracks in the door, the cooling system tries to compensate for the heat loss by continuous operation. Over time, a “coat” of ice builds up on the evaporator, which further worsens heat transfer, creating a vicious circle of problems. The compressor works at its limit, but the cold inside does not increase.
You can check the tightness with a simple test with a sheet of paper. Clamp the sheet between the door and the body around the perimeter. If the paper is pulled out without resistance or falls out easily, it means that the seal is not sealing in this place. Also carefully inspect the rubber for:
- 🧐 Microcracks and tears through which air passes.
- 🍞 Adhesion of crumbs or fat that prevents tight closure.
- 📉 Loss of elasticity when the rubber becomes hard and does not straighten out.
If the seal is simply dirty, it is enough to wash it with warm water and a mild detergent. In case of loss of elasticity, you can try to restore the shape using a hairdryer: heat the deformed area and straighten it, pressing it with something heavy until it cools. However, if the rubber is cracked or torn, only a complete replacement will help. The new tape will ensure a perfect fit and relieve the motor.
Freon leak and capillary tube blockage
More serious reasons why the refrigerator does not turns off, lies in the malfunction of the refrigeration circuit. If a microcrack has formed in the system and a refrigerant (freon) outletoccurrence occurs, the pressure drops. The compressor tries to reach the required temperature by working non-stop, but due to a lack of gas, the cooling efficiency drops to zero. In this case, it may be warm in the chamber, but the back wall is barely warm.
Another common problem is clogged capillary tube. Oil and freon circulate in the system, and over time, plugs of paraffin or oxidation products may form in the narrow channel of the capillary. The circulation of the refrigerant stops, the pressure in different parts of the circuit becomes critical, and the engine idles. Only a specialist with a manometric manifold can distinguish these malfunctions from a thermostat breakdown.
Symptoms of a leak or blockage are often similar:
- 🔊 The compressor runs constantly, but does not turn off.
- 🌡️ The temperature in the chambers does not drop to the set values.
- ❄️ The evaporator is covered with an uneven layer of frost or completely clean.
- 🔥 The condenser (grid at the back) remains cold or warm only partially.
Repair in this case requires evacuation of the system, searching for leaks (often using a leak detector), replacing the filter drier and refilling with new freon. It is impossible to perform these operations independently without special equipment and skills. Attempts to “top up” the gas without eliminating the cause will only temporarily alleviate the situation.
Malfunctions of the motor-compressor and start relay
If all the sensors are working, the freon is in place, and the door is closed hermetically, the problem may lie in the very “heart” of the refrigerator - the compressor. Over time, mechanical wear of parts leads to a drop in performance. The motor hums, trying to create the required pressure, but the valves no longer hold the freon effectively. As a result, he is forced to work around the clock in order to maintain at least some cold.
It is also worth paying attention to starting relay. This small element is responsible for starting the engine. If the relay contacts are burnt or the mechanism is stuck, the compressor may not receive a command to stop or, on the contrary, it may constantly try to start, humming and clicking. You can check the relay by gently knocking on it (sometimes shaking the contacts helps) or ringing with a tester.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| Humming, but not cooling | Freon leak or compressor breakdown | Call a technician to diagnose the circuit |
| Works without stopping, the chamber is very cold | Faulty thermostat | Replacing the thermostat |
| Clicks and hums, then silence | Faulty starting relay | Replacing the starting relay |
| Humming, warm condenser | Clogged capillary system | Cleaning the system and replacing the filter |
Electronic module errors control
In modern models with a system No Frost and electronic control, the main module is responsible for all processes. If the triac that controls the compressor burns out on the control board, or a software failure occurs, the equipment may “freeze” in active operation mode. The electronics simply stops receiving signals from the temperature sensors.
Rebooting the system often helps solve the problem. To do this, you need to:
- Disconnect the refrigerator from the power supply.
- Wait at least 10-15 minutes for the capacitors to completely discharge.
- Turn on the device again and check its operation.
If after rebooting the situation repeats itself and the display shows codes errors (for example, F1, E2, etc.), professional diagnostics are required. The technician will check the voltage at the module output and, if necessary, resolder the burnt elements or replace the entire board. Repairing electronics yourself without circuit knowledge is extremely risky.
⚠️ Attention: Do not try to disassemble an electronic module if you do not have experience working with a soldering iron and electronics. Improper intervention can lead to a short circuit and failure of other expensive components.
☑️ Diagnostics of continuous operation
Frequently asked questions (FAQ)
How long can the refrigerator operate without stopping?
In normal mode, the refrigerator operates cyclically: it works for about 15-20 minutes and rests for 20-30 minutes. Continuous operation is only permissible in the “Super Freeze” mode (usually up to 8-12 hours, after which it should turn off on its own or by a timer). If the unit hums without a break for more than 24 hours in normal mode, this is a malfunction.
Why does a new refrigerator work without interruption on the first day?
When first turned on or after long-term transportation and defrosting, the refrigerator needs time to cool the entire internal volume and chamber walls. During this period, the compressor can work for several hours in a row. This is normal if after 5-7 hours it turns off.
Is it possible to operate the refrigerator if it does not turn off?
For a short time - you can while you are waiting for the technician. Long-term operation in this mode will lead to overheating of the motor windings, oil burnout and other compressor failure. Electricity bills will also increase significantly. It is better to temporarily turn off the device.
Does the number of products affect the operating time?
Yes, it does. A fully loaded refrigerator takes longer to operate because the food has a greater heat capacity. However, after the temperature rises, the cycle should stabilize. An empty refrigerator, on the contrary, cools faster, but when the door is opened, the cold disappears faster, which can increase the frequency of switching cycles.
What to do if the refrigerator does not turn off after defrosting?
After defrosting, let the appliance work for 2-3 hours without loading. If the cycle has not returned to normal during this time, check the thermostat. During defrosting, moisture may have entered the sensor, causing a short circuit or incorrect readings. An ice plug could also form in the condensate drainage system.