The situation when a household refrigerator stops turning off and hums around the clock causes concern for any owner. This not only causes your energy bills to skyrocket, but also creates constant background noise that interferes with your relaxation. Moreover, continuous operation of the motor in non-stop mode is fraught with serious overheating and failure of expensive components of the unit.
Before calling a technician or disassembling the equipment, it is necessary to carry out initial diagnostics. Often the problem lies not in the breakdown of electronics, but in violation of operating rules or external factors. Understanding the principles of operation refrigeration circuit will help you quickly determine the source of the malfunction and make the right decision on repairs.
In this article we will examine in detail the main scenarios that lead to endless operation of the compressor, and ways to eliminate them. We will consider both simple user errors and complex technical malfunctions that require specialist intervention.
Seal failure and temperature conditions
One of the most common reasons why the compressor does not go into rest mode is a violation of the thermal balance inside the chambers. If warm air from outside enters the refrigerator, the control system detects the increase in temperature and commands the motor to operate continuously until a predetermined threshold is reached. Most often, the culprits are loosely closed doors or damaged rubber seals.
Pay attention to the condition seal. Over time, the rubber loses elasticity, cracks or moves away from the body. Even a microscopic gap leads to constant infiltration of warm air. Check the tightness with a simple test: press a piece of paper between the body and the door in different places. If the paper is removed freely without resistance, the tightness is broken.
⚠️ Attention: If you notice freezing of a “coat” or ice only on one side of the chamber or in the corner next to the door, this is a direct sign of warm air leaking through a leaky joint.
More One factor is installing the unit near heat sources. Placing the refrigerator next to a heating radiator, gas stove or in direct sunlight causes thermostat to constantly record a high temperature. In such conditions, the equipment does not physically have time to cool the internal volume to the required values.
- 🔍 Check the tightness of the door around the entire perimeter.
- 🧹 Clean the seal from fat and crumbs that interfere with tight closure.
- 🌡️ Make sure that there is a gap around the refrigerator for ventilation.
- ☀️ Move the equipment away from the battery or window.
Malfunctions of the thermostat and sensors
If everything is in order with the tightness, the next target for checking is thermostat (thermostat). This device is responsible for monitoring the temperature inside the chamber and sending a signal to turn the compressor on or off. In older models with mechanical control, the thermostat is a relay with a bellows that responds to changes in refrigerant pressure in the capillary tube.
In modern models with a system No Frost and electronic control, the control function is performed by temperature sensors (thermistors). If the sensor “lies” and sends a signal to the control module that the chamber is warm, although in fact it is already cold there, the motor will work without stopping. Often the problem lies in oxidation of the contacts or displacement of the sensor from the evaporator.
How to check a mechanical thermostat?
To check a mechanical thermostat, it can be temporarily excluded from the circuit by closing the contacts directly. If the compressor starts and turns off normally when artificial cooling is applied (or turned on), then the problem is in the regulator itself. However, this method requires skills in working with electricians!
Symptoms of a malfunctioning thermostat often manifest themselves not only in continuous operation, but also in incorrect temperature conditions. Food can freeze or, conversely, spoil, even if the motor is constantly humming. In some cases, adjusting the thermostat rod helps, but more often a complete replacement of the unit is required.
Problems with the refrigerant and circulation system
Freon leakage is an insidious malfunction that is often disguised as other problems. When the quantity refrigerant in the circuit decreases, the cooling efficiency decreases. The compressor tries to compensate for the lack of cold by working in enhanced mode, but cannot reach the target temperature, and therefore does not turn off.
It is difficult to determine a leak visually, since freon is colorless and odorless. However, there are indirect signs: poor cooling when the motor is running, hot side walls (instead of moderately warm) or, conversely, a cold condenser. Also, swelling or rust may appear on the evaporator tubes in places of microdamage.
| Symptom | Probable cause | Action |
|---|---|---|
| The engine is hot, but there is no cold | Freon leak or blockage | Call a technician to find a leak |
| The refrigerator turns off, but rarely | Lack of refrigerant | Refilling the system |
| Audible gurgling | Normal circulation or air in the system | Observation |
| The tubes are unevenly covered with frost | Impaired circulation | Checking the capillary tube |
It is important to understand that you can fix the leak yourself and fill the system almost impossible without specialized equipment, such as a vacuum pump and a pressure gauge station. Attempts to simply add freon without eliminating the cause of the leak will only give a temporary effect.
Malfunctions of the compressor and start relay
The most expensive and serious problem is the wear of the compressor itself compressor. Over time, the motor-compressor loses its performance: the piston group wears out, the valves let gas through, and the pressure in the system is not pumped up to the required values. As a result, the refrigerator works constantly, trying to build up pressure, but does not turn off.
Often the culprit of continuous operation becomes starting relay. This small element is responsible for starting the engine and protecting it from overloads. If the relay is “stuck” in the closed state, current continues to flow to the compressor windings even after reaching the desired temperature. This can be determined by a characteristic click when trying to start or the absence of a shutdown click.
Diagnostics of the compressor requires measuring the discharge pressure and current consumption. If the current is below rated and the pressure does not increase, the compressor has “died” or lost compression. If the current is normal, but the refrigerator does not turn off, there may be a problem in the hydraulic resistance of the system (clogging).
- 🔊 Listen: a steady hum or intermittent clicks?
- 🔥 Touch the motor housing: moderate heat is normal, a hot housing is a sign of overload.
- ⚡ Measure the current consumption: deviation from the passport indicates a problem.
- 🔧 Check the starting relay for contact carbon deposits.
Clogged capillary tube and moisture removal system
There are narrow holes in the refrigerant circulation system areas called capillary tubes. Their diameter is extremely small, which makes them vulnerable to blockages. The cause may be moisture that has entered the circuit during poor-quality repairs, or products of oxidation and oil breakdown. Ice plug or debris blockage blocks the freon flow.
If there is a blockage, the compressor works at its limit, trying to push the refrigerant through the obstacle. The pressure at the outlet of the compressor increases, and at the inlet it decreases. This leads to the fact that the sensors do not detect the required cooling, and the cycle is not interrupted. A characteristic sign of a blockage is a hot condenser and a cold filter drier.
⚠️ Attention: Attempts to clean the capillary tube yourself often lead to depressurization of the system or damage to the compressor. A professional nitrogen purge and replacement of the filter drier are required.
In addition, in refrigerators with a No Frost system, continuous operation may be caused by a malfunction of the defrost system. If Defrost heating element, the timer or shutdown sensor does not work, the evaporator becomes overgrown with ice. The fan stops driving air, the cold does not enter the chamber, and the motor works without interruption.
☑️ Diagnostics of the No Frost system
Electronic control module
In modern refrigerator models, the entire process is controlled electronic module. This is the “brain” of the device, which collects data from all sensors and makes a decision about turning on the compressor. If the triac that controls the motor has burned out in the control board, or a software failure has occurred, the shutdown command may simply not be received.
Symptoms of module failure are often accompanied by chaotic behavior of indicators, errors on the display, or complete ignoring of the control panel buttons. In some cases, the module may “glitch” due to power surges in the network, sending false signals about high temperatures in the chambers.
Diagnostics of the electronic unit requires special knowledge and equipment. Burn marks, swollen capacitors, or blackened tracks are often visible visually on the board. Repairing the module is possible, but it is often more economically feasible to replace it with a new one, especially if the equipment is not under warranty.
Frequently asked questions (FAQ)
Why does a new refrigerator work constantly on the first day?
This is normal. After the first load of food or defrosting, the refrigerator requires time (up to 24 hours) to cool the entire volume of the chamber and stabilize the temperature. If after a day it does not turn off, this is a cause for concern.
Can the refrigerator not turn off in the summer due to the heat?
Yes, in hot weather, heat exchange is difficult, and the compressor takes longer to cool. However, it should still turn off periodically. If the room is +30°C, the operating cycle may shift towards longer operation, but not into non-stop mode.
Is it dangerous to leave a refrigerator running without stopping?
Yes, it is dangerous. The compressor is not designed to work without interruptions; it will quickly overheat, the oil will lose its properties, and the motor will burn out. In addition, there is a risk of wiring fire or insulation melting.
How much does it cost to repair if the refrigerator does not turn off?
The cost depends on the reason. Replacing a thermostat or relay is inexpensive. If you need to search for leaks, evacuation and refilling of freon, or replace the compressor, the cost of repair can be up to 50-70% of the cost of a new device.
How to extend the life of the compressor?
Regularly defrost the refrigerator (if there is no Frost), do not put hot foods inside, keep the condenser clean in the back and provide good ventilation around case.