Situation when household appliances begin to behave unpredictably, always causing concern to the owner. If the refrigerator either freezes or does not freeze, this is a sure sign that there is a failure in the cooling or control system. Such temperature changes can lead to spoilage of food, the appearance of an unpleasant odor and even complete failure of the unit. Unlike a complete failure of the compressor, periodic operation requires a more in-depth diagnosis, since some components can function only partially.
In this article we will analyze in detail the mechanics of such malfunctions so that you can understand whether it is worth calling a technician or the problem can be solved yourself. We will consider both simple operating errors and complex technical breakdowns that require professional intervention. Understanding the operating principle of your model Indesit, Atlant or Bosch will help you quickly localize the source of the problem.
Faults of the thermostat and temperature sensors
The most common cause of unstable operation is the failure of the thermostat or electronic sensor. It is this element that is responsible for sending a signal to turn the compressor on and off depending on the temperature inside the chambers. If the contacts are stuck or the sensor transmits incorrect readings, the control system is “lost” and stops starting the motor on time.
In older models with mechanical control, the capillary tube of the thermostat itself often breaks. It may lose its seal or become displaced, which is why it does not feel the actual heating of the evaporator. In modern units with a system No Frost an electronic thermistor is responsible for this process, which can oxidize or fail due to power surges in the network.
⚠️ Attention: If you notice that the refrigerator turns on for a very short time and immediately turns off, do not try to endlessly turn the thermostat knob. This can permanently damage the start relay or the compressor itself.
To diagnose a mechanical thermostat, you can try gently knocking on its body or slightly heating it with a hairdryer (carefully!) to check whether the mechanism clicks. However, in most cases it is required replacing a part for a new one, since repairing old thermostats is not economically feasible. Electronic sensors are checked with a multimeter for resistance.
Problems with the start relay and compressor
When the refrigerator stops freezing, but still hums or makes clicking noises, the start relay is often to blame. This device starts the compressor motor. If it is burned out or jammed, the motor may hum but not start, or it may start and stall after a few seconds due to the thermal protection.
The compressor is the “heart” of the refrigerator. If it works intermittently, this may indicate an interturn short circuit of the windings or the exhaustion of the mechanical part. In such cases, the unit may either cool or warm up, trying to start. A critical sign is the situation when the compressor heats up to 80-90 degrees Celsius in 2-3 minutes of operation.
Let's consider the main symptoms of a motor-compressor malfunction:
- 😐 The engine is humming, but does not start, a characteristic click is heard.
- 🔥 The compressor housing becomes hot to the touch in a matter of minutes.
- 📉 The refrigerator turns on rarely, but works for a very long time without shutting down.
- 🔌 The circuit breaker in the electrical panel trips when turned on equipment.
Replacing a compressor is a complex procedure that requires evacuation of the system and charging with freon. It is impossible to perform this operation independently without special equipment. If the diagnostics showed a motor malfunction, you must contact a service center.
Refrigerant leak and capillary system clogged
If a microcrack has formed in the freon circulation system, the gas gradually evaporates. In this case, the refrigerator may take a long time to gain temperature, then turn off according to a timer or thermostat command, but not provide the required cold. After a while, it will turn on again, trying to compensate for the lack of cold, creating the illusion of unstable operation.
Clogged capillary tube is another common cause. An ice plug of moisture may form in a narrow channel or oil breakdown products may accumulate. This creates excess pressure before the blockage and a vacuum after it. The compressor operates with overload, the system either cools weakly or stops freezing at all.
Signs of a leak or blockage often appear visually:
- ❄️ Uneven areas of frost are visible on the back wall of the refrigerator or evaporator.
- 🧊 Bloating side walls of the case due to expansion of insulation during defrosting.
- 🛢️ The appearance of oily spots under the refrigerator or near the compressor.
To eliminate these problems, you need to call a technician. He will find the leak using a leak detector, seal it, replace the filter drier and charge the system with the required amount of refrigerant. Independent attempts to “top up” freon without eliminating the leak will only give a temporary effect.
Failures in the operation of the defrost system (No Frost)
In refrigerators with the system No Frost periodic freezing and thawing is a normal mode. However, if this cycle is disrupted, the unit stops freezing normally. The main elements of the defrost system: heating element (heating element), defrost sensor and timer (or electronic module).
If the heating element burns out or the sensor is stuck, a huge coat of ice grows on the evaporator. The fan stops moving air and the cold does not enter the chamber. The compressor can run continuously, trying to cool the sensor, but there will be no effect. After complete manual defrosting (for 24 hours), the refrigerator may work, but after a week the problem will return.
How to check the defrosting heating element?
To check the heating element, you need to “ring” it with a multimeter. The resistance of a working heater is usually from 200 to 400 ohms. If the device shows a break (one on the screen), the heating element requires replacement. Also check the integrity of the wiring going to the heater, as it often burns out due to high temperature.
Often owners confuse a defrost system malfunction with a compressor breakdown. It is important to distinguish between these conditions. If, after defrosting, the refrigerator started working like new, but after 5-7 days it stopped freezing again, the problem is definitely in the defrosting system.
Improper operation and external factors
The reason does not always lie in the breakdown of parts. Sometimes the refrigerator sometimes freezes, sometimes it doesn’t due to simple user errors or external conditions. For example, if the unit is located close to a wall or in a niche, the air circulation around the condenser is disrupted. The compressor overheats and goes into protection.
Loading warm products or a door that is not tightly closed can also cause chaotic operation. Warm, moist air enters the chamber, the sensors record a sharp jump in temperature, and the motor wears out. After some time, the system may “lock up” and stop responding adequately.
Check the following operating parameters:
- 🚪 The door seal must fit tightly around the entire perimeter, not allowing light to pass through.
- 🌡️ The room temperature should not exceed +30°C, otherwise the equipment will not cope.
- 🧹 The rear grille must be clean, without a layer of dust and animal hair.
⚠️ Attention: Never install the refrigerator next to heating radiators, ovens or in direct sunlight. This is guaranteed to lead to overheating and unstable operation.
Diagnostics and table of symptoms
To make it easier for the technician to diagnose the problem, or so that you can understand the scale of the disaster yourself, use the table below. Compare the symptoms of your equipment with the described signs.
| Symptom | Probable cause | Difficulty of repair |
|---|---|---|
| Buzzes, but does not start | Start relay or wedge compressor | Average |
| It freezes slightly, ice freezes | Freon leak or blockage | High |
| On for 1 minute, off | Thermostat or sensor is faulty | Low |
| Works non-stop, little cold | Defrost system or leak | Medium/High |
You may need a multimeter to carry out initial diagnostics. It can be used to check the integrity of power circuits, the resistance of windings and sensors. However, remember about safety precautions: all work with electrical circuits is carried out only with disconnected from the network the device.
☑️ Actions before calling a technician
When professional repairs are needed
There are a number situations where independent repair is not only useless, but also dangerous. If the problem is related to a sealed circuit (leak, compressor replacement, system cleaning), you cannot do without special tools. Also, you should not go inside if the equipment is under warranty - you will break the seals and lose the right to free service. Modern models of refrigerators are equipped with complex electronic control modules. Diagnostics of such boards requires special knowledge and equipment. An error in programming or soldering can lead to failure of all electronics.
Modern refrigerator models LG, Samsung And Whirlpool equipped with sophisticated electronic control modules. Diagnostics of such boards requires special knowledge and equipment. An error in programming or soldering can lead to the failure of all electronics.
If you notice the following signs, call a specialist:
- 🔥 The smell of burning or melted wiring.
- 💧 A large amount of water under the refrigerator (not melted).
- 🔊 Loud knocking, grinding or vibration during operation.
- ⚡ Frequent knocking out of traffic jams in the apartment.
⚠️ Attention: Equipment manufacturers are constantly updating design solutions. Parts that fit a 2020 model may not fit a similar 2026 model. Always check the compatibility of spare parts by serial number.
Why the refrigerator turns on immediately turns off?
This is a classic symptom of a faulty start relay or thermal protection. The motor tries to start, consumes a lot of current, the protection trips and opens the circuit. After a while the cycle repeats. Less often, a faulty compressor with a jammed piston behaves this way.
Is it possible to use a refrigerator if it does not freeze well?
For a short time - yes, but the food may spoil. Long-term operation in this mode is dangerous for the compressor, which wears out trying to reach the set temperature. This can lead to its complete combustion.
How often do you need to defrost a No Frost refrigerator?
The No Frost system does not require regular defrosting to remove ice, as it does this automatically. However, once every year and a half, a complete defrosting for 24 hours is recommended for hygienic treatment and odor removal, as well as to check the operation of the defrosting system.
What to do if it is warm in the refrigerator and ice in the freezer?
Most likely, the air supply channels from the freezer to the refrigerator compartment are clogged. This often happens with the No Frost system. The unit needs to be defrosted. If the problem repeats, the defrosting system is faulty or the air duct is clogged.