The situation when food in the refrigerator compartment is cooled normally, and the freezer turns into a useless box with a positive temperature, causes panic in any home cook. This is a classic symptom of an imbalance in the refrigerant circulation system or a failure in the control electronics. In contrast to the complete failure of the equipment, here the compressor continues to hum, the light is on, and the illusion of normal operation is created until the stocks of meat or dumplings begin to melt.
Modern two-chamber units, be it Indesit, LG or Bosch, are designed so that cold is generated in one circuit or block, and then distributed among the chambers. If the distribution is disrupted, it is the freezer that suffers, since it requires lower temperatures for freezing. Understanding the principle of operation evaporator and thermostat will help you not only diagnose the problem, but also avoid costly calling a technician for diagnosing an obvious malfunction.
Before hitting alarm and look for a service center, it is necessary to conduct a primary visual and auditory diagnosis. Often the reason lies in a banal violation of operating rules or system overload. However, if you hear that the engine is running without stopping, or, conversely, turns on extremely rarely, this already indicates a specific unit that requires intervention.
Primary diagnosis: why the compressor is humming, but there is no cold
The very first step is to determine the nature of the compressor operation. If it hums continuously without turning off for hours, it means that the system is trying to compensate for the loss of cold, but cannot achieve the set parameters. In this case, the culprit is often a freon leak or a capillary tube blockage. Refrigerant is the “blood” of the refrigerator, and without sufficient pressure it will not be able to effectively remove heat from the freezer.
Otherwise, when the motor turns on for a few minutes and sits for a long time, the problem may be thermostat or temperature sensor. The electronics “think” that it is already -20°C in the freezer and turns off the cooling, although in reality it may be -5°C or higher. False readings from sensors are a common cause, especially in models with the system No Frost.
⚠️ Attention: If you smell burnt wiring or see sparking in the compressor area, immediately unplug the device. Continuing operation in this condition may lead to a fire.
It is also worth listening to the sounds that the unit makes. Gurgling, hissing, or complete absence of sound when the engine is running can tell an experienced diagnostician more than a visual inspection. For example, the complete absence of the sound of gas circulation when the compressor is running often indicates a clogged filter-drier.
Problems with the defrosting system in No Frost refrigerators
For owners of equipment with the system No Frost a situation when the refrigerator is working but the freezer is not freezes, most often associated with a malfunction of the defrost system. The essence of the problem is that a “coat” of ice is growing on the evaporator, hidden behind the back wall. This ice blocks the flow of cold air, and the fan simply drives warm air around the chamber.
In normal mode, the defrosting heating element should periodically turn on and melt the ice. If this does not happen, ice accumulates until it completely blocks the air ducts. The main culprits for this situation are:
- ❄️ Faulty defrost heating element —the heating element burns out and stops heating.
- ❄️ Timer failure defrost —the mechanism “gets stuck” in the cooling mode and does not give the command to defrost.
- ❄️ Malfunction of the defrost sensor —the sensor incorrectly reads the evaporator temperature and does not allow heating to start.
To test this hypothesis, it is not necessary to immediately disassemble the unit. Try defrosting the refrigerator completely. Unplug it, open the doors and leave it for at least 24 hours (preferably two days). If, after turning on, the freezer starts working and keeps the cold for several days, and then the problem repeats, the diagnosis is confirmed: the defrosting system does not work.
Why can’t you chip off ice with a knife?
Mechanical removal of ice with a knife or sharp objects is strictly prohibited. You can damage the evaporator tubes, which will lead to an immediate release of freon and expensive repairs, which are often not economically feasible.
It is important to note that in some models, for example, in old Samsung or Whirlpool, the defrost sensor may fail due to oxidation of the contacts. In such cases, sometimes simple cleaning of the contacts helps, but more often the element needs to be replaced.
Freon leakage and system blockage: how to distinguish
If defrosting did not help, and the compressor works around the clock, trying to catch up with the temperature, most likely the problem is the refrigerant. A freon leak is not always a visible oil stain under the refrigerator. Microcracks in the foamed part of the body or in the door heating circuit can poison the gas for years until its quantity becomes critical for the operation of the freezer.
A blockage of the system is a “twin” of a leak in terms of symptoms, but with a different physical cause. Oil circulates in the system, which over time can thicken or mix with compressor wear products, forming a plug in a narrow capillary. Filter drier, designed to retain moisture and debris, can also become clogged, blocking the freon flow.
It is difficult to diagnose these conditions at home, but there are indirect signs:
- 🧊 The condenser grille (at the back) remains only partially cold or warm.
- 🧊 Partial thawing appears in the freezer or the ice lies unevenly.
- 🧊 The compressor is very hot to the touch (but not incredibly hot).
⚠️ Attention: Self-filling the refrigerator with freon is impossible without special equipment (vacuum pump, pressure gauge station, scales). An attempt to “just add gas” without evacuation of the system will lead to the formation of an ice plug and the final failure of the compressor.
In case of a leak or blockage, you need to call a technician with equipment to find the location of the damage, solder the copper tubes and refill the system in compliance with the dosage and type of oil.
Compressor malfunctions: when the motor powerless
The compressor is the heart of the refrigerator. If it is "tired" it may run but not create enough pressure to pump freon through the entire system. This often happens with double-circuit compressors or in units where one motor serves two chambers through a solenoid valve.
Signs of a “weak” compressor:
The motor operates quietly, without characteristic vibration, or, conversely, makes a metallic clang. At the same time, the condenser (grid at the back) is barely warm. In such cases, they say that the compressor “does not hold pressure.” This may be due to wear of the piston group or valves inside the mechanism.
Another common problem is a faulty start relay. If the relay is stuck or burned out, the compressor may hum for several seconds, click and turn off without starting. Or it can start, but work incorrectly, without developing full power.
Replacing a compressor is a complex procedure that requires resoldering the tubes, vacuuming and refilling. If your refrigerator is more than 10 years old, repairs with replacement of the compressor can cost 60-70% of the price of a new device, which calls into question its economic feasibility.
Electronics failure and problems with the thermostat
In modern models with electronic control (where the temperature is set by degrees on the display), the control module is responsible for the operation. If the board is glitchy, it may be sending incorrect signals to the compressor or fan. For example, the board may “think” that the freezer is cold enough and turn off the cooling.
In mechanical models (with a knob inside), the thermostat is responsible for turning it on/off. If its capillary tube has lost its seal or the contacts are burnt, the refrigerator will stop turning on or will work without interruption. For a freezer, this is critical, since constant operation without rest cycles can lead to freezing or, conversely, defrosting if it breaks down.
Let's compare the main symptoms:
| Fault | Symptom | Reaction compressor | Temperature in the freezer |
|---|---|---|---|
| Freon leakage | Compressor hot, grille cold | Works without stopping | Gradually increases to 0°C |
| System clogged | Filter is cold, condenser is partially warm | Works without stopping or turns off due to overload | Does not fall below -5°C |
| Fault Heating element | Ice on the back wall (after opening) | Works as usual | Grows due to lack of circulation |
| Thermostat failure | The refrigerator does not turns off or does not turn on | Constantly on or silent | Depends on the failure mode |
Electronics diagnostics require a multimeter to test the circuits. Often the problem is solved by replacing the NTC temperature sensor, which is inexpensive, but replacing it requires disassembling the internal panel.
Operation rules and prevention of breakdowns
Many problems when the freezer stops freezing are caused by improper operation. For example, loading hot products. If you place a pot of soup in the chamber, the system will suffer heat shock. The compressor will work hard, trying to cool the volume, and the moisture will instantly turn into an ice coat on the evaporator, blocking the system No Frost.
Densely packing the freezer also disrupts air circulation. Air should pass freely through the grille and be distributed throughout the volume. If you plug all the holes with bags, the cold simply will not reach the upper or lower drawers.
☑️ Check before calling a technician
⚠️ Attention: Regularly check the condition of the rubber seal on the freezer door. If it is cracked or does not fit tightly, warm, moist air is constantly entering the chamber. This leads to increased ice formation and overload of the compressor.
Also, do not forget to clean the condenser (black grille at the back) from dust and animal hair at least once a year. A condenser clogged with dust does not give off heat well, the pressure in the system increases, and the freezing efficiency decreases.
Frequently asked questions (FAQ)
Why did the freezer work after defrosting, but after a week it stopped again?
This is a classic sign of a malfunction of the defrosting system. Ice has again accumulated on the evaporator and blocked the channels. You need to check the defrost heating element, defrost sensor and timer (or control module). Most likely, one of these elements requires replacement.
Is it possible to use a refrigerator if the freezer does not freeze?
You can use the refrigerator compartment, but with restrictions. However, it is not recommended to leave equipment in this condition for a long time. A compressor running idle or overloaded (if there is a leak) can burn out. In addition, the food in the freezer will spoil, creating a favorable environment for bacteria.
How much does repair cost if the compressor burns out?
The cost consists of the price of a new compressor, replacement work, soldering, vacuuming and refilling with freon. On average, this is 40-60% of the cost of a new refrigerator. For older models, it is often more profitable to buy a new unit than to repair the old one.
Why does ice freeze in the freezer on only one side?
Uneven distribution of ice or cold often indicates a partial blockage of the system or the beginning of a freon leak. This may also be a sign that the fan in the system No Frost works weakly or is frozen and touches the ice with its blades.
How to understand that a freon leak has occurred in the foamed part?
This can only be accurately determined by exclusion and professional equipment. If the tubes are externally intact, there is no oil anywhere, and freon leaves, most likely there is a microcrack in the foamed circuit (inside the housing). Repair in this case is complicated and often requires the installation of an external evaporator (“crying shelf” inside the chamber).