The situation when the refrigerator compressor hums continuously, and the rest cycle never occurs, always causes alarm. This not only increases energy bills, but also signals that the cooling system is operating in emergency mode. Continuous operation of the motor can lead to serious consequences if the first symptoms of a malfunction are ignored.
Often, equipment owners notice the problem too late, when the products have already begun to deteriorate or a thick layer has appeared on the walls of the chamber ice. Constant load on the engine reduces its service life by several times, bringing about an expensive overhaul or complete replacement of the unit.
In this article we will look in detail at why your refrigerator stopped turning off and will help you determine whether you can solve the problem yourself or it’s time to call a technician. Understanding the principles of operation of the refrigeration circuit will help you quickly diagnose a breakdown.
The influence of external factors and improper operation
Before you panic and look for faults in the “insides” of the unit, it is worth analyzing the conditions in which it is located. Often the reason is trivial and lies in violation of operating rules. Room temperature plays a key role: if the refrigerator is located near the radiator, in direct sunlight or in a too hot kitchen, the motor simply cannot cope with heat removal.
The compressor tries to compensate for external heating by working at wear It is also important to check the tightness of the rubber seal door. If the cuff is worn out, dirty or deformed, warm air constantly flows into the chamber. Sensors detect an increase in temperature and prevent the system from going into standby mode.
⚠️ Attention: Make sure that the refrigerator is level. If the feet are not adjusted, the door may not close completely, creating a microscopic but constant gap for heat to enter.
Another common factor is the placement of hot food. If you put a pot of freshly cooked soup in the chamber, the refrigerator will work until it cools the volume to the specified values. This creates an extreme load on refrigerant and the compressor.
Malfunctions of the thermostat and temperature sensors
One of the most common reasons why the refrigerator does not click or turn off is the failure of the thermostat. This mechanical or electronic component is responsible for opening the compressor power circuit when the desired temperature is reached. If the contacts thermostat are stuck in the “on” position, the motor will run endlessly.
In modern models with a system No Frost or electronic control, air sensors are responsible for this process. They can transmit incorrect data to the control module, reporting that the chamber is still warm, although in fact it is already cold there. As a result, the command to stop the engine is not received.
To diagnose a mechanical thermostat, you can try gently knocking on its body or slightly turning the adjustment knob. If the characteristic click is not heard, and the motor continues to hum, the part most likely requires replacement. Electronic sensors are checked for resistance with a multimeter, which requires partial disassembly of the chamber.
Problems with the defrosting system in No Frost refrigerators
If your refrigerator is equipped with an automatic defrost, and it stopped turning off, while a “coat” of ice formed on the back wall of the freezer, the problem lies in the defrosting system. Evaporator is covered with an ice crust that blocks the circulation of cold air.
The fan circulates air, but it does not cools properly. The temperature sensor sees that the required degrees have not been reached and keeps the compressor on. In such a situation, the culprits may be:
- ❄️ Defrost heating element - a heating element that could burn out.
- ⏱️ Defrost timer - a mechanism that does not switch the refrigerator to defrost mode.
- 🌡️ Defrost sensor - detects incorrect evaporator temperature.
- 💧 Drainage hole - clogged with debris, and water has nowhere to drain, it freezes.
Visual inspection of the evaporator (often this requires removing the plastic panel in the freezer) will help confirm the presence of ice. If there is ice, but the heating element does not heat, the defrost circuit is not working. It is also important to check whether ice has frozen on the sensor itself, distorting its readings.
Why does ice interfere with operation?
The ice crust on the evaporator works as a heat insulator. The cold from the freon is not transferred to the air in the chamber, so the sensor “thinks” that there is no cooling, and the motor works constantly, trying to break through this ice barrier.
Refrigerant leakage and system blockage
When a leak occurs in the freon circulation circuit, the amount of refrigerant decreases. The compressor begins to work longer, trying to “catch up” with the temperature, but due to lack working substance efficiency drops. As a result, the motor runs around the clock, but the refrigerator barely cools or does not cool at all.
A similar situation is observed when the capillary tube is clogged. This can happen due to moisture in the system that has entered during poor-quality repairs, or due to oil breakdown products. In both cases, the normal circulation cycle is disrupted, and pressure in the system becomes incorrect.
⚠️ Attention: It is absolutely forbidden to look for a leak on your own or try to clean the capillary without a vacuum pump and pressure gauges. You can damage the tubes or release residual freon.
An indirect sign of a leak is often a hot condenser (grid on the back or sides of the housing) only partially, or vice versa - it remains cold, although the compressor is humming. If clogged, the condenser can be very hot, and the evaporator can be warm.
Wear of the compressor and start-up relay
The most expensive breakdown is wear of the very heart of the refrigerator. Over time piston group the compressor wears out and compression is lost. The motor hums, trying to create pressure, but cannot gain the required speed or maintain pressure in the circuit.
Often the start-protection relay fails along with the compressor. If its contacts are burnt, the engine may not start the first time or work intermittently, which is perceived by the electronics as the need for constant operation.
| Symptom | Possible cause | Sound character |
|---|---|---|
| Buzzes, but does not cold | Freon leak / Compressor wear | Monotonous hum |
| Clicks and buzzes | Faulty start relay | Frequent clicks |
| Works without stopping | Thermostat / Heat leakage | Smooth operation |
| The body gets very hot | Clogged system / Dirty capacitor | Normal or enhanced |
If the compressor begins to operate noticeably louder, with a metallic clanging or vibration, this is a sure sign of its imminent demise. In such a situation replacement of the compressor often economically infeasible for older models of refrigerators.
☑️ Diagnostics before calling a technician
Electronic control module errors
In modern refrigerators, the entire process is controlled by the “brain” - an electronic module. If a power surge occurs in its circuit or some element burns out, it may issue incorrect commands. For example, keep the start contact compressor open all the time.
Module diagnostics require special knowledge and equipment. Burn marks or swollen capacitors are often visible visually on the board. However, sometimes the breakdown is hidden, and you can understand that it is the module that is to blame by eliminating other faults.
If the refrigerator is “glitchy” - the indicators are flashing, the settings are lost, and the motor does not turn off, there is likely a control problem. Repairing the module is possible, but requires resoldering of the elements in a service center.
When an urgent call to a technician is necessary
There are a number of situations when independent experiments can only do harm. If you checked the seal, defrosted the unit (which took at least 10-12 hours), made sure the socket was working properly, but the problem remained, you need professional help. Especially when it comes to opening the refrigeration circuit.
A master is needed if:
- 🛠️ The compressor needs to be replaced or refilled with freon.
- 🔌 Clear traces of a short circuit are visible short circuits in the wiring.
- ❄️ The No Frost system is completely frozen over and does not defrost.
- 🔊 A burning smell has appeared or the humming has been replaced by a knock.
Remember that trying to solder the tubes yourself or replace the filter-drier without vacuuming the system will lead to to the fact that the refrigerator will stop cooling completely after a short time.
⚠️ Attention: If you smell a specific smell of gas or see oil under the refrigerator, immediately unplug the appliance, open the windows and do not turn on electrical appliances. This may indicate a leak of flammable refrigerant.
How much does the repair cost?
The cost consists of the work of the technician, the cost of spare parts (compressor, thermostat, freon) and travel. Replacing a thermostat is a budget repair; replacing a compressor is one of the most expensive types of repair of household appliances.
Frequently asked questions (FAQ)
Can the refrigerator not turn off due to the heat outside?
Yes, if the room temperature exceeds 30-32 degrees, a standard refrigerator may not be able to cope with the heat influx and work non-stop. In such cases, improving ventilation around the cabinet or installing an air conditioner in the room helps.
How long should the refrigerator run after defrosting?
After complete defrosting (24 hours) and turning on, an empty refrigerator usually takes 2 to 4 hours to reach temperature and turn off. If it works for more than 6-8 hours without stopping, this is a sign of a malfunction.
Is it harmful for the motor if it does not turn off for a day?
Extremely harmful. Compressors are designed for cyclic operation. Long-term work without rest leads to overheating of the windings, thickening of the oil and accelerated wear of rubbing parts, which can lead to a wedge of the motor.
Why does a new refrigerator not turn off for a long time when it is first turned on?
This is normal. When first started, the system should cool the entire internal volume from room temperature to operating temperature (-18°C in the freezer). This process can take up to 12 hours, especially if the chamber was loaded with products right away.
Is it possible to use a refrigerator if it does not turn off, but freezes?
It can be used, but not for long. This is emergency mode. Food can freeze, and the compressor will burn out at any moment. It is better to reduce the load on the chamber (open the door briefly so that the sensor works) and do diagnostics.