The situation when the refrigerator does not turn offcauses panic among most owners of household appliances. The hum of the compressor, which sounds around the clock, and an ice crust on the back wall are sure signs that the system has broken its usual operating cycle. In normal mode, the unit should gain cold, turn off for rest and turn on again as needed, but if it breaks down, this rhythm gets lost.
Often users notice that refrigerator it hums continuously, and inside the chamber it becomes too cold, up to the freezing of products that should simply cool down. This happens because the control unit or mechanical components do not receive or ignore the signal that the desired temperature has been reached. Ignoring the problem for more than 24 hours can lead to complete failure of the compressor due to overheating of the windings.
In this article we will analyze in detail why the equipment behaves so aggressively, which malfunctions cause constant freezing and can you eliminate them yourself. Understanding the principles of operation of thermostats and sensors will help you quickly diagnose the problem without resorting to expensive service in cases where this is possible.
The principle of operation and why the cycle is broken
Standard cooling cycle is built on the interaction of the compressor, refrigerant and temperature control systems. When you set the mode to Settings → Temperature, you set a target value to which the air inside the chambers should cool. As soon as the sensor detects reaching this point, it sends a signal to break the circuit and the motor stops.
If the refrigerator freezes and does not turn off, this means that the "Stop" command is simply not received or is ignored. The system may “think” that it is still warm inside, even if the food has already turned into ice. This is a classic feedback error, where the actuator (compressor) runs idle, without receiving data about the real state of the environment.
A leak in the circuit or wear of the seals can also cause the unit to work without interruption. In this case, the cold constantly escapes outside, and the temperature sensor located inside detects an increase in degrees and requires the compressor to work harder. It turns out to be a vicious circle in which the equipment tries to compensate for the leakage of cold.
Malfunctions of the thermostat and temperature sensors
The most common reason why refrigerator does not turn off is the failure of the thermostat (thermostat). This is a mechanical or electronic device that physically opens contacts when cooled. If its contacts are “stuck” in the “On” position or the bellows tube has burst, the compressor will hum endlessly.
In modern models with a system No Frost or Full No Frost electronic sensors (thermistors) are responsible for control. They change their resistance depending on the temperature. If the sensor “lies” and shows the controller that the chamber is +10°C instead of the real -5°C, the control board will keep the compressor on.
- 🔧 Mechanical thermostat: often fails due to vibration or moisture, requiring replacement of the entire unit.
- 📉 Evaporator sensor: if it is faulty, the refrigerator may not switch to defrost mode, becoming overgrown with ice and continuing to freeze.
- 🔌 Wiring break: oxidation of contacts or break of the sensor wire leads to loss of signal and emergency continuous operation.
For diagnostics of mechanical The thermostat often needs to be temporarily closed. If after this procedure the compressor starts and works, but when disconnected it stalls, then the problem is in the regulator. However, with electronic systems, everything is more complicated: here you need a multimeter to measure the resistance of the sensor at different temperatures.
Problems with the door seal and cold leakage
It would seem that a simple rubber band on the door cannot be cause serious damage, but statistics say otherwise. If seal damaged, dirty or simply lost elasticity, warm air from the room constantly penetrates into the chamber. Moisture from this air condenses and freezes, and the temperature sensor requires more and more cold.
Visually you can notice that refrigerator is covered with a “coat” of ice in those places where air leaks. Most often these are the corners of the door or the bottom of the opening. In such a situation, the compressor works hard, trying to cool the incoming warm air, and simply does not have time to enter the shutdown cycle.
⚠️ Attention: Do not try to soften the hardened seal with boiling water - this can damage the rubber structure. Use a hair dryer at a minimum temperature or special sprays to restore elasticity.
Often the problem is solved by thoroughly washing and degreasing the surface of the door and the seal itself. Grease and sticky food marks prevent a tight seal. If the rubber has cracks or creases, it must be replaced, since gluing at home gives only a temporary effect.
Failures in the operation of the control module and electronics
In inverter and modern compressor models, the "brain" is electronic control module. It processes signals from all sensors and makes a decision to turn the motor on or off. If the compressor control triac on the board burns out or there is a failure in the firmware, the relay may “stick” in a closed state.
Symptoms of electronics failure are often accompanied by other oddities: blinking indicators on the panel, chaotic backlighting, or erroneous codes on the display. In this case, refrigerator can freeze all the way, ignoring any temperature settings that you are trying to set.
Sometimes the problem lies not in the board itself, but in power surges in the network that damaged the input circuits. To protect expensive equipment, it is recommended to use voltage stabilizers, especially in houses with old wiring. Repairing a module requires qualifications and special equipment, so in 90% of cases the unit needs to be replaced.
Is it possible to reset electronics errors yourself?
In some models, a full reset (Hard Reset) helps. To do this, you need to unplug the refrigerator for 15-20 minutes. This allows the capacitors on the board to discharge and reset temporary logic errors. If the problem was a software failure, the equipment may work normally.
The influence of fast freezing and overload mode
The reason is not always a breakdown. Owners often accidentally activate the function Super Freeze (Super Freeze) or Quick Cool. In this mode, the refrigerator is forced not to turn off for a certain time (usually from 8 to 24 hours) in order to quickly freeze a large batch of food.
If you forget to turn off this function, the unit will work without interruption. Check the control panel: often the mode indicator is on, but due to the bright light in the room it is not visible. Also, the reason may be a banal overload of the chambers with warm products, which the normal mode simply cannot cope with.
The table below shows the comparative characteristics of the normal mode and the intensive freezing mode so that you can understand the difference in the behavior of the equipment:
| Parameter | Normal mode | Super Freeze mode |
|---|---|---|
| Compressor operating time | Cyclic (40 min work / 20 min rest) | Continuous (up to 24 hours) |
| Temperature in freezer | -18°C... -20°C | Up to -24°C and below |
| Energy consumption | Standard | Maximum |
| Shutdown | Automatic by sensor | Only by timer or manually |
☑️ Checking the settings before calling the technician
When an urgent call to the technician is necessary
There are a number of situations when independent experiments can lead to a fire or final breakdown refrigerator. If you smell a burning smell, see sparking in the compressor area, or notice that the body of the unit (especially the side walls) is heating up to critical temperatures, immediately disconnect the device from the mains.
Also, professional help is needed if after defrosting for 24 hours the situation has not changed and refrigerator started again work without stopping. This indicates a deep technical malfunction associated with a freon leak or blockage of the capillary system, which requires evacuation and refilling with refrigerant.
⚠️ Attention: Do not try to open the cooling circuit yourself or solder pipes without a license and equipment. Refrigerants can be explosive, and moisture entering the system will lead to costly repairs.
If your model is under warranty, any DIY repair (even replacing a light bulb or seal) may be grounds for denial of warranty service. In such cases, it is better to immediately contact an authorized service center, even if the problem seems minor.
Prevention and proper operation
To compressor served for a long time and worked normally, it is important to follow the operating rules. Regular defrosting (for drip systems) and cleaning the drainage hole prevents ice buildup that can block temperature sensors. A clean heat exchanger on the back wall also contributes to efficient.
Do not place hot food in the chamber and ensure that food does not block the ventilation openings. Air circulation is a key factor for stable operation. If you notice that refrigerator started to work longer than usual, check whether the temperature in the room has changed (for example, in the summer or when the heating is on).
Timely maintenance extends the life of the equipment. Once every six months, check the integrity of the seal and clean the condenser from dust (if it is an open type). These simple steps will help avoid a situation where the unit begins to wear out.
Why does the refrigerator hum, but does not freeze, and does not turn off?
This is a classic sign of a refrigerant (freon) leak. The compressor tries to pump gas, but there is not enough of it to create pressure, so the temperature does not drop and the sensor does not give a shutdown command. A leak search and refilling is required.
Can the refrigerator not turn off due to the heat in the room?
Yes, if the room temperature is above +30°C, heat exchange is disrupted. The refrigerator runs longer to compensate for heat gain. In extreme heat, it can work almost without interruption, which is harmful for it.
What to do if after defrosting the refrigerator does not turn off again?
If defrosting (lasting 12-24 hours) did not help, the problem is technical. Most likely, the thermostat, sensor, or electronics failure has occurred. It is necessary to call a technician for diagnostics.
Is it harmful for the compressor to work without stopping?
Extremely harmful. The compressor is designed for cyclic operation. During continuous operation, the oil does not have time to return to the crankcase, overheating of the windings and mechanical wear of the rubbing parts occurs, which leads to a wedge of the motor.
How to check if the thermostat is working at home?
In mechanical models, you can carefully remove the temperature regulator and short-circuit the two wires going to the compressor. If the engine starts, the chain is intact. To accurately check the resistance, you need a multimeter and “continuity” of the contacts when the temperature of the sensitive element changes.