The situation when The refrigerator operates intermittently and can scare any owner: the appliances hum and then go silent, food begins to thaw, and condensation appears on the walls. Unstable operation of the unit is not just discomfort, it is a direct threat to the safety of food supplies and a signal that a failure has occurred in the system. Users often notice that the motor-compressor turns on for a short time and immediately stalls, or, conversely, it works without stopping, but does not freeze.
The reasons for this behavior can lie in both banal power surges in the network and serious mechanical damage to the components. Understanding why the refrigerator works intermittentlywill help you make the right decision: call a technician or try to fix the problem yourself. In this article we will analyze in detail the main factors influencing the stability of the compressor and cooling system.
Sometimes the problem is solved by simply replacing the socket or moving the unit away from the battery, but in most cases diagnostics of internal components is required. Inverter compressors, for example, they may behave differently than traditional ones linear models, which often confuses the initial diagnosis. It is important not to ignore the first symptoms, since long-term operation in emergency mode can lead to complete failure of an expensive unit.
Problems with power supply and starting relay
The first thing that needs to be eliminated when equipment is unstable is the quality of the supplied voltage. If the light flickers frequently in your apartment or there are jumps, the refrigerator may go into protective mode or simply not start. Start relay is a small but critical element that provides an impulse to start the motor. If the contacts inside it are oxidized or burnt, the compressor will try to start, hum, but immediately turn off.
A frequent cause of failures is the failure of the start-protection relay. This component is responsible for turning off the starting winding after the motor rotor accelerates. If the mechanism sticks, the engine cannot reach operating mode and stalls. In older models, the relays can be electromagnetic, in new ones - thermal or combined, and each has its own operating life.
⚠️ Attention: If you hear a loud click, followed by a hum and a second click after a few seconds, most likely the problem is in the start relay or compressor windings. Operating equipment in this mode is dangerous - the motor may burn out.
It is also worth checking the integrity of the network cable and the condition of the socket. Poor contact at the junction of the plug and socket causes sparking and voltage drop, which is perceived by the electronics as an emergency situation. If you use an extension cord, try connecting the refrigerator directly to a stationary outlet - this often solves the problem of a “floating” contact.
Malfunctions of the thermostat and temperature sensors
The thermostat (thermostat) is the “brain” that commands the compressor to turn on when the temperature in the chamber rises above the set one. If this element malfunctions, the refrigerator begins to work chaotically. For example, he may not feel that the chamber is already warm and not turn on the motor, or, conversely, not turn it off when the cold is reached. In modern models with electronic control, this is responsible for temperature sensors (thermistors), which can give incorrect readings due to oxidation of contacts or internal break.
Diagnostics of the thermostat in mechanical refrigerators is often carried out by the method of elimination. If, when the thermostat contacts are closed, the compressor starts and operates normally, then the culprit has been found. In electronic models, a sensor error is usually displayed on the display in the form of a code, which can be found in the instructions for a specific model LG, Samsung or Bosch.
Sometimes the problem lies not in the sensor itself, but in its location. If the mechanical thermostat's capillary tube becomes dislodged or damaged, it will not correctly read the evaporator temperature. This leads to the cooling cycle being disrupted, and the unit working with long breaks or, conversely, without stopping.
How to check the thermostat with a multimeter?
To check, you need to remove the thermostat and ring its contacts. In the normal state (at room temperature), the contacts should be closed (resistance close to zero). If you place the sensitive part of the thermostat in the freezer for 10-15 minutes, the contacts should open (infinite resistance). Lack of response indicates a malfunction of the part.
Refrigerant leak and system blockage
One of the most serious reasons why the refrigerator operates intermittently is a violation of the tightness of the circuit. Freon is a working fluid that transfers heat. If its quantity in the system decreases due to microcracks in the pipeline or corrosion, the pressure drops. The compressor tries to compensate for the lack of cold and works longer than usual, but due to the built-in temperature or current protection, it periodically turns off.
Leakage symptoms are often accompanied by swelling of the side walls of the refrigerator or the appearance of rust in the places where the tubes are soldered. A situation may also occur when the freezer compartment is still freezing, and in the refrigerator compartment the temperature is much higher than normal. Clogged capillary tube gives similar symptoms: the compressor creates pressure, but freon does not circulate, which leads to overheating and engine stoppage.
| Symptom | Possible cause | Nature of compressor operation |
|---|---|---|
| The compressor is hot, but does not start | Faulty start relay or windings | Buzzes for 3-5 seconds, clicks, is silent |
| The refrigerator works without stopping | Freon leak or thermostat failure | Works continuously without turning off |
| Long pauses between switching on | Clogged capillary system | Works in short cycles with long breaks |
| Strong vibration and noise | Unbalance or wear of the suspension | Works intermittently, buzzing louder than usual |
Restoring tightness and refilling with freon is a task for professionals that requires special equipment: a vacuum pump, a pressure gauge station and scales. It is almost impossible to fix a leak on your own and correctly calculate the refrigerant dosage without the risk of permanently damaging the system.
Wear of the motor-compressor
The motor-compressor is the heart of the refrigerator, and its wear is a natural process, especially for equipment older than 10 years. Over time, the rubbing parts wear out, the gaps increase, and the compressor ceases to create the necessary pressure. As a result, it can start, but not “pull” the system, going into overheating protection. This is a classic situation when the refrigerator turns on and off. at short intervals.
You can determine compressor wear by the characteristic sound and temperature of the case. If the motor hums strainedly, vibrates more than usual, and its temperature exceeds 80-90 degrees, most likely the part’s service life is coming to an end. Also, a sign of a dying compressor may be the smell of burning or scorched insulation in the engine compartment area.
⚠️ Attention: Attempts to “reanimate” an old compressor by installing a more powerful starting relay or capacitor (the so-called “Hard Start”) give only a temporary effect. This can lead to final jamming of the piston group and expensive repairs.
In modern models with inverter compressors diagnosis is more difficult, since they operate smoothly, without characteristic switching clicks. Interruptions in their operation are often associated with a malfunction of the control board, and not the motor itself. Therefore, before changing the compressor, it is necessary to check the electronics.
Influence of the external environment and operating conditions
Sometimes the reason for unstable operation lies not inside the refrigerator, but in the conditions in which it is located. Placing the unit close to a wall, next to heating appliances, or in direct sunlight interferes with heat transfer. The condenser (black grille at the back) does not have time to give off heat, the pressure in the system increases, and the compressor is often forced to turn off or work with overload.
It is also important to take into account the climate class of the equipment. If a refrigerator designed for a temperate climate (SN, N) is placed in an unheated room in winter or in a hot kitchen in summer, it will work intermittently. The oils in the compressor may thicken in the cold or become too liquid in the heat, which will disrupt the lubrication of the components.
☑️ Checking the operating conditions
Do not forget about ventilation. If you have built a refrigerator into a niche in a kitchen unit, make sure that there are ventilation holes there. The lack of air flow leads to overheating of the electronics and motor, causing chaotic switching on and off.
Faults in the control board and wiring
In modern refrigerators, all processes are controlled by an electronic control module. Voltage surges, moisture, or simply a manufacturing defect can lead to failure of individual board elements. In this case, signals from the sensors may be processed incorrectly, and the compressor receives erroneous start or stop commands.
Often the problem lies in oxidation of the contacts in the connectors or chafing of the wires inside the housing. Vibration during compressor operation weakens the connections over time, which leads to loss of contact. This causes the effect of a “floating” fault, when the refrigerator either works normally, then interruptions begin.
Diagnosing the control board requires special equipment and knowledge in the field of electronics. Visually, only obvious signs of damage can be identified: swollen capacitors, blackening, traces of burning. If you find such defects, further operation of the equipment is prohibited.
Diagnostics and elimination methods
If your refrigerator begins to work intermittently, the algorithm of actions should be consistent. First, exclude external factors: check the socket, the voltage in the network, the tightness of the door. Then listen to the sounds of the running motor and pay attention to the nature of its activation.
For deeper diagnostics, you may need a multimeter. With its help, you can check the integrity of the compressor windings, the resistance of the thermostat and the presence of voltage at the input to the control board. However, if you are not confident in your abilities, it is better not to risk it.
Is it possible to replace the starting relay yourself?
Yes, if you have the skills to work with the tool and access to spare parts. It is necessary to remove the old relay, photograph the connection diagram and install the new one, strictly observing the polarity and orientation (usually indicated by the UP arrow). However, if the reason is not in the relay, you will waste time and money.
Why does the refrigerator turn on for 1 minute and turn off?
This is a classic sign of thermal (protection) tripping. The motor tries to start, the current increases, but due to a mechanical obstacle (jamming) or an electrical fault (interturn short circuit), it cannot spin up. The thermal relay heats up and opens the circuit to prevent a fire.
Does the amount of product affect the operation of the compressor?
Yes, it does. An empty refrigerator heats up faster when the door is opened, causing the compressor to turn on more often. A completely clogged refrigerator makes it harder for cold air to pass through, which can disrupt circulation. The optimal load is about 50-70% of the volume.
Regular maintenance, cleaning the condenser from dust and monitoring the condition of the seals will help extend the life of your refrigerator and avoid sudden breakdowns. Remember that prevention is always cheaper than repairing or replacing equipment.
What to do if the refrigerator is defrosted?
If food has defrosted, do not rush to refreeze it. It is better to cook meat and fish immediately or dispose of them. Vegetables and fruits may lose their taste. After fixing the problem, let the refrigerator run empty for 2-3 hours so that it reaches the temperature before loading food.