Why the refrigerator does not turn off: a complete analysis of the reasons

The situation when The refrigerator does not turn off i works non-stop, is one of the most common problems faced by owners of household appliances. The constant hum of the compressor not only irritates the ear, but also signals serious problems in the operation of the cooling system. Ignoring this symptom can lead to critical consequences: from food spoilage to complete failure of an expensive unit.

In normal operation, the compressor of the refrigeration unit turns on and off cyclically, maintaining the set temperature inside the chambers. If the motor hums continuously, this means that thermostat or another control system does not receive a signal that the required parameters have been achieved. Understanding the causes of the failure is the first step to successful repair or proper operation of the device.

Overload with products and impaired air circulation

One ​​of the banal but common reasons for the constant operation of the compressor is improper loading of the refrigerator. If you've just returned from the store and your shelves are completely stocked with food, it takes significantly more time and energy for the system to cool a large volume of warm items. During this period, compressor can work without interruption for several hours, which is a normal reaction to the thermal load.

However, the problem may lie not only in the quantity, but also in the location of the products. In modern models with system No Frost and conventional drip cooling, free circulation of cold air is critical. If the shelves are packed to capacity or the products are placed close to the back wall, the temperature sensors may not read the data correctly, causing the motor to run idle.

Users often make the mistake of placing hot or even just warm pots and pans inside the chambers. This creates extreme stress on the refrigerant engine. The system will try to compensate for the sharp temperature rise, working to wear out.

• 🍖 Do not place hot foods inside, let them cool to room temperature.
• ❄️ Leave gaps between foods for free movement of air flow.
• 🌡️ Do not block the ventilation holes on the back wall of the package or with dishes.

If, after unloading the refrigerator and ensuring proper air access, the situation has not changed within 12 hours, you should look for a deeper technical malfunction.

Malfunction of the thermostat (thermostat)

The thermostat is the “brain” that makes the decision to turn the compressor on or off. It is he who reads the temperature inside the chamber and opens the electrical circuit when the goal is achieved. If this element fails, the circuit does not break, and refrigerator continues to freeze indefinitely, often leading to the formation of an ice coat even in the positive chambers.

In mechanical models, the thermostat is a device with a bellows filled with freon and a contact group. Over time, the contacts may become stuck in the closed position, or the bellows may lose its seal. In electronic models, this function is responsible temperature sensors, which can also give erroneous readings due to oxidation of contacts or a software failure.

⚠️ Attention: If you notice that the refrigerator does not turn off, and the food in the main chamber has frozen, turning into ice, with a 90% probability the problem lies in the thermostat or sensor.

To diagnose a mechanical thermostat, it is often necessary to “test” it with a multimeter. If the resistance does not change when the temperature of the pin changes or the circuit remains closed, the part must be replaced. In electronic systems, diagnostics are more complicated and require checking error codes on the display.

Refrigerant (freon) leak

Leak freon is one of the most insidious reasons why the refrigerator stops turning off. The principle here is the opposite: the compressor runs non-stop not because it “doesn’t want” to stop, but because the system cannot reach the set temperature due to a lack of refrigerant. The pressure in the circuit drops, and the motor tries to compensate for this by continuous operation.

Leakage can occur in microscopic portions through factory defects in welds, corrosion of evaporator tubes or mechanical damage during transportation. It is impossible to visually notice a gas leak, since freon is colorless and odorless. However, an indirect sign may be the lack of cold when the engine is running or the appearance of yellowish spots on the walls of the freezer (at the site of an oil leak).

It is extremely difficult to repair the leak and refill the system on your own. Required:

• 🔧 Specialized equipment for finding leaks (leak detectors).
• 💨 Vacuum pump to remove moisture and air from the system.
• ⚖️ Accurate scales for refrigerant dosage.

Attempts to simply “top up” freon without eliminating the cause of the leak will only give a temporary effect, after which the problem will return in a few weeks or months.

Problems with the door seal

The tightness of the refrigerator compartment is the key to stable operation. If sealing rubber (cuff) on the door is worn out, cracked or simply dirty, warm air from the room constantly enters the chamber. Sensors detect the temperature increase and give the command to the compressor to turn on. Since the heat is constantly supplied, the shutdown cycle may never occur.

Often the problem lies not in the rubber itself, but in the misalignment of the door or weakening of the hinges. In this case, even the new seal will not fit tightly around the entire perimeter. You can check the tightness with a simple “sheet of paper test”: press a sheet of paper between the door and the body in different places. If the sheet is pulled out without resistance, the seal is broken.

To restore functionality, you can try:

1. Wash the seal thoroughly with warm water and soap, removing grease and plaque.
2. Warm the deformed areas with a hairdryer and straighten them.
3. Adjust the position of the door by tightening the fastening bolts of the hinges.

If the rubber cuff has lost elasticity and becomes cracked, it must be replaced with a new one, selected for a specific model of the refrigeration unit.

Malfunction of the control module and starter relay

Modern refrigerators are controlled by complex electronics. If control module (the board) fails, it can send incorrect signals to the compressor. For example, due to a power surge in the network, triacs or other elements of the control circuit could burn out, “locking” the motor in the on state.

It is also worth paying attention to the starting relay. This device is responsible for starting the engine and protecting it. If the relay is stuck in the on position, the compressor will run continuously. This is often accompanied by a characteristic click, after which the motor does not stop, or, conversely, a hum without starting (if the relay is faulty in another phase).

Repairing the electronic board often requires resoldering elements or completely replacing the module, which is an expensive procedure.

The influence of external factors and placement

Sometimes the reason lies not inside the equipment, but in the conditions of its operation. If the refrigerator is installed next to a heat source (battery, stove, in direct sunlight), the cooling system is overloaded. The heat exchange is disrupted, and condenser (the grill at the back) does not have time to cool, which leads to the compressor constantly turning on.

It is also important to take into account the temperature in the room. Most refrigerators are designed to operate in the range from +10°C to +32°C (climate class SN-T). If the room is colder than +10°C (for example, in an unheated country house in winter), the oil in the compressor thickens and the thermostat may not respond correctly. If it is hotter than +32°C, the refrigerator simply cannot cope with the heat influx.

⚠️ Attention: Installing the refrigerator close to the wall (less than 5-10 cm gap) disrupts the ventilation of the condenser, which also causes continuous operation of the motor.

Check whether the equipment is not standing in a niche where air circulation is completely blocked. In such cases, the only solution is to move the unit to a more suitable location.

Diagnostics and self-test algorithm

Before calling a technician, you can carry out an initial diagnosis to eliminate simple errors. This will help you more accurately describe the problem to a specialist or even solve the issue yourself. Remember that any work with electricity requires disconnecting the device from the network.

Start with visual inspection and listening. If the compressor works, but there is no cold, this is one group of problems. If it freezes too much and doesn’t turn off, use another one. Check the temperature settings: perhaps one of the household members accidentally set the “Super Freeze” mode.

If simple methods did not help, a more in-depth check will be required.

When professional repair is needed

There are a number of situations when self-repair is not only ineffective, but also dangerous. If you suspect a freon leak, work with chemicals and high pressure is required. An attempt to “top up” the gas without evacuation of the system will lead to the formation of an ice plug in the capillary and the final failure of the equipment.

Professionals are also needed when replacing a compressor. This is a complex procedure that requires soldering the tubes in a nitrogen protective environment. Improper soldering may result in fire or explosion. In addition, modern inverter compressors require special setup and testing.

The main signs of the need to call a technician:

• 🛠️ The appearance of a characteristic smell of burnt wiring or oil.
• 🔊 The compressor hums, but does not start, or starts with with a loud click.
• ❄️ Oily yellow spots are visible on the walls of the chamber.
• ⚡ power surges in the network that damaged the electronics.

Do not delay contacting service. Long-term operation of the compressor in emergency mode leads to its overheating and burnout of the windings, which increases the cost of repairs several times.

Frequently asked questions (FAQ)