The situation when a household refrigerator begins to operate unstably, forcing the owner to wonder whether it will turn on again after another shutdown, is one of the most stressful in the operation of equipment. You approach the unit and hear silence, although it should be cold inside, or, on the contrary, the motor hums for too long without stopping, and then suddenly stops. Operation cyclicity - this is a normal phenomenon for a working device, but if the pauses become chaotic or too long, this is a signal of a malfunction.
Understanding why the refrigerator turns on and off without apparent logic requires careful observation of accompanying symptoms. Sometimes the problem lies in a simple power surge or overheating, while in other cases it is a serious breakdown or refrigerant leak. Ignoring the first signs of unstable operation can lead to complete damage to the products and expensive repairs. compressor or refrigerant leak. Ignoring the first signs of unstable operation can lead to complete product damage and costly repairs.
In this article we will analyze in detail the main reasons why your The refrigerator may operate intermittentlydiagnostics Do not rush to call a technician at the first strange sound - perhaps you can fix the problem on your own by simply checking the integrity of the wiring or the thermostat settings.
Normal operation mode versus malfunction
Before sounding the alarm, you need to clearly understand the difference between normal operation and real breakdown. A working refrigerator does not operate continuously 24 hours a day; Its job is to maintain the set temperature, so it turns on and off periodically. This process is regulated thermostat, which gives the command to start the compressor when the temperature in the chamber rises above the set norm.
However, there are signs that clearly indicate that the operating mode is disrupted. If you notice that the intervals between starts are becoming shorter and shorter, and the period of engine operation itself is increasing, this may indicate a loss of cooling capacity. In such a situation, the equipment simply does not have time to reach the required temperature in a standard cycle.
The critical symptom is the so-called “idling”, when a start click is heard, the engine tries to start, hums for a few seconds and turns off again. This condition is often accompanied by a warm condenser or a complete lack of cooling in the chambers. If the refrigerator turns on for only 10-20 seconds and turns off, this is an emergency compressor protection mode.
⚠️ Attention: If you hear a loud click when you try to start, followed by silence, do not try to immediately plug the appliance back into the network. Allow the compressor to cool for 2-3 hours to avoid a wedge in the piston group.
For clarity, compare the parameters of normal and emergency operation in the table below. This will help you quickly navigate the situation.
| Parameter | Normal operation | Symptoms of malfunction |
|---|---|---|
| Operation duration | 10-20 minutes | More than 40 minutes without stopping |
| Idle time | 20-40 minutes | Less than 5 minutes or complete absence |
| Startup sound | Smooth buzzing | Clicks, buzzing followed by shutdown |
| Temperature inside | Stable | Gradually rising or food thawed |
Problems with power supply and starting relay
One of the most common reasons why refrigerator it behaves unpredictably is voltage surges in the household network or a malfunction of the start-up relay. If the voltage at the outlet drops below the permissible level, the compressor may simply not start, although the indicators on the panel may light up. In modern models with electronic control, low voltage causes malfunctions control module.
The starting relay is a small mechanism that provides an impulse to start the engine. If the contacts inside the relay are oxidized or burned, current does not flow to the compressor windings at the right time. As a result, you hear a characteristic click, the motor jerks but does not start, and after a few seconds the protection turns off the power supply again. Often in such cases, the relay requires replacement, which is a relatively inexpensive procedure.
It is also worth paying attention to the condition of the power cord and plug. A visually good plug may have an internal defect causing intermittent contact. At the slightest movement of the refrigerator or vibration, the contact disappears and the unit turns off. Check if the plug is heating up during operation - this is a sure sign of poor contact.
☑️ Power supply diagnostics
It is important to note that frequent power outages can damage not only the relay, but also itself compressor. If your area has an unstable network, it is highly recommended to use a voltage stabilizer. This device will protect expensive equipment from premature failure.
How to check the starting relay yourself?
To check the relay, it must be removed from the compressor. Shake it: if you hear a ringing sound inside (like a coin), it means that the core is loose or damaged, and the relay must be replaced. You can also “ring” the contacts with a tester, but a visual inspection for burning is often more informative.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” that decides when the refrigerator needs to cool the chamber and when you can rest. If this device fails, it may produce incorrect signals. For example, the contacts inside the thermostat may “stick,” which is why the compressor either does not turn on at all or runs continuously, ignoring the achieved temperature.
In models with a system No Frost and electronic control, air temperature sensors are used instead of a mechanical thermostat. If such a sensor is contaminated with ice or is displaced from its place, it reads incorrect data. The refrigerator may “think” that the chamber is already -25°C and turn off the compressor, although in reality the temperature there is above zero.
- 🌡️ Mechanical thermostat: It often fails due to loss of tightness of the bellows tube, as a result of which freon evaporates and the contacts do not close.
- 💻 Electronic module: It may generate a sensor error if the contacts on the board have oxidized or a power surge has occurred.
- ❄️ Freezing sensor: In No Frost systems, the sensor may become overgrown with ice, which distorts the temperature readings.
Diagnostics of the thermostat often requires its “exclusion” from the circuit. If, when the thermostat contacts are closed (bypassing it), the refrigerator starts to work normally and freeze, then the problem is in this unit. However, remember that for mechanical thermostats, correct calibration is important when installing a new element.
⚠️ Attention: Before replacing the thermostat, be sure to wait until the refrigerator is completely defrosted (at least 24 hours). Moisture that gets into the contacts of a new device or onto the control board can cause a short circuit.
Protection against overheating and problems with the capacitor
The refrigerator compressor generates a significant amount of heat during operation. To cool it, a condenser is used - a lattice radiator, usually located at the back or on the sides of the case. If this radiator is contaminated with dust, animal hair, or is moved too close to the wall, heat transfer is impaired.
As a result overheating The thermal protection relay built into the compressor or starting device is triggered. It forcibly opens the circuit to prevent the motor windings from burning out. After cooling (which can take from 30 minutes to several hours), the relay closes the circuit again, the motor starts, heats up quickly and turns off again. This cycle can be repeated endlessly.
Particular attention should be paid to the location of the refrigerator. The operating instructions for any brand (Indesit, Bosch, LG, Samsung) require a gap of at least 5-10 cm from the back wall to the furniture. Ignoring this rule is a common reason why a new refrigerator suddenly stops working normally in the summer, when the room temperature is already high.
It is also worth checking the operation of the fan (in No Frost models). If the fan blowing the condenser or evaporator is jammed or burnt out, heat will not be removed effectively, which will lead to frequent overheating shutdowns.
Freon leak and capillary tube blockage
The most serious technical problems that cause unstable operation are associated with the refrigeration circuit. A refrigerant (freon) leak causes the pressure in the system to drop. The compressor tries to reach the required pressure, runs for a long time, but due to a lack of gas, it cannot reach the thermostat cut-off temperature. As a result, it either works non-stop or turns off due to overheating.
Similar symptoms are observed when the capillary tube is clogged. An ice or dirt plug forms in the freon circulation system, which blocks the flow of refrigerant. The pressure at the outlet of the compressor increases, and at the inlet it drops, which causes incorrect operation of the unit. Often in such cases, you can hear gurgling or hissing inside the chambers.
- 🔍 Visual inspection: Look for oily stains on the tubes or at the compressor connection - this is a sign of a leak.
- 👂 Audio diagnostics: The sound of a running pump during a leak often changes, becoming quieter or, conversely, with signs "vacuum".
- 🌡️ Evaporator temperature: If there is a leak or blockage, the evaporator may become overgrown with an uneven layer of frost ("coat").
Repair of such troubleshooting at home is impossible, since it requires evacuation of the system, searching for leaks using a leak detector, and refilling with freon using a scale. Attempts to simply “add gas” without eliminating the cause of the leak will only give a temporary effect.
Compressor malfunctions: when replacement is required
The compressor is the heart of the refrigerator. If it fails, the symptoms can vary. Wear of the mechanical part leads to the fact that the motor cannot create the necessary pressure. It hums, heats up, but does not start or runs intermittently. In such cases, thermal protection is often triggered.
There is the concept of “compressor wedging,” when the piston group jams due to exhaustion or lack of lubrication. Attempts to start such a unit lead to a strong hum and a quick shutdown. Sometimes a short-term supply of increased voltage helps (which is what the craftsmen do), but most often a complete replacement of the unit is required.
It is important to distinguish a noisy start from a breakdown. Older compressors may hum louder, but if the hum is accompanied by a metallic clanging or knocking sound, it's a bad sign. It is also worth checking the fastening of the compressor itself to the frame: if the shock absorbers are dry, vibration will be transmitted to the body, creating the illusion of unstable operation.
⚠️ Attention: Replacing a compressor is a complex procedure that requires soldering pipes in a nitrogen environment. Do not attempt to change the compressor yourself without the appropriate skills and tools, as improper soldering will lead to repeated failure in a short time.
Frequently asked questions (FAQ)
Why does the refrigerator turn on immediately after turning off?
This may indicate a malfunction of the thermostat, which does not sense that the temperature is already reached, or due to a freon leak, which is why the cold does not hold. It is also possible for the compressor to overheat if ventilation is impaired.
Can a voltage surge cause a breakdown?
Yes, sudden voltage surges can damage the start relay, control module, or even the compressor windings. It is recommended to use stabilizers or surge protectors to protect equipment.
How long should a refrigerator normally operate?
In normal mode, the operating cycle is approximately 10-20 minutes of operation and 20-40 minutes of rest. The exact ratio depends on the room temperature, the load of the chambers and the thermostat settings.
What to do if the refrigerator hums but does not start?
Most likely, the problem is in the start relay or the compressor itself. Try defrosting the unit for a day. If after turning on the situation repeats, you need to call a technician to diagnose the electrical part.
Does the amount of food affect the operating mode?
Yes, a completely empty refrigerator operates in shorter cycles, since the air cools quickly. However, if the chamber is densely packed with products, air circulation is disrupted, and the compressor has to work longer for uniform cooling.