The situation when food turns to stone in the freezer, and warmth reigns in the main compartment, is familiar to many owners of household appliances. This is a classic symptom of poor cold circulation or a malfunction in the temperature control system. Users often panic, believing that the unit has completely failed, but in reality the problem may lie in a specific part that requires replacement or adjustment.
In modern models, especially with the system No Frost, one evaporator and one fan are often responsible for cooling both compartments. If air stops flowing into the upper part, it means that a “plug” has formed somewhere. In two-compressor devices, the situation is different: there is a separate motor responsible for each circuit, and the breakdown of one should not affect the other, except for problems with electronics or general tightness.
Before calling a technician, it is necessary to carry out an initial diagnosis. It will help you understand whether the breakdown is critical or a temporary failure. It is important not to ignore the first signs, since long-term storage of food at the wrong temperature will lead to their spoilage, and operating equipment in emergency mode can damage an expensive compressor.
Problems with the No Frost system and freezing of the evaporator
The most common cause of uneven cooling in systems No Frost is the evaporator freezing. In such models, cold air is forced by a fan from the freezer into the refrigerator compartment through special channels. If these channels or the evaporator itself are covered with ice, the air flow is blocked, and the cold simply does not reach the upper shelves.
A system consisting of a heating element, a timer (or electronic module) and a defrost sensor is responsible for defrosting the evaporator. If one of these elements fails, the ice does not melt, but grows with each compressor cycle. Visually, this may not be noticeable, since the evaporator is hidden behind a plastic panel inside the freezer.
⚠️ Attention: If you notice that the back wall of the freezer is covered with a thick layer of frost or ice, and the fan hums intermittently or does not make noise at all, this is a sure sign of problems with defrosting. Operation in this mode leads to overload of the engine.
To eliminate the malfunction, it is often necessary to completely defrost the refrigerator for 10-12 hours. This will allow the ice to melt naturally. If, after connecting to the network, the problem returns after 1-2 weeks, it means that one of the elements of the defrost system needs to be replaced. Replacing the heating element yourself requires partial disassembly of the freezer and skills in working with a multimeter.
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 500 Ohms. If the device shows a break (infinity), the element must be replaced. It is also important to check the integrity of the wires going to the heating element, as they often rot or break at the bends.
Refrigerant leakage: a hidden threat to equipment
The second most popular reason why the freezer works, but the refrigerator does not cool is a partial leak of freon. The refrigerant circulates in a closed circuit, and if a microcrack appears in the tubes, the gas begins to evaporate. The pressure in the system drops, and the refrigerant ceases to effectively cool the evaporator of the main compartment, having time to completely evaporate while still in the freezer.
A leak can occur anywhere in the circuit: in the foamed part of the body, in the joints of the tubes or in the condenser. This is often preceded by metal corrosion or mechanical damage during transportation. A characteristic sign is that the compressor works almost non-stop, trying to compensate for the lack of cold, but the temperature in the upper compartment does not drop below +10...+15 degrees.
Diagnostics of leaks at home is difficult, as it requires special equipment - a leak detector or a pressure gauge station. However, an indirect sign may be that the condenser (grid at the back) is only half hot or that it is completely cold when the engine is running. Also, an oily coating may appear on the tubes at the gas outlet.
| Symptom | Probable cause | Necessary actions |
|---|---|---|
| The compressor hums incessantly | Freon leak or blockage | Switch off, call a technician to find a leak |
| Ice only at the entrance to the freezer | Lack of refrigerant | Refilling and soldering required |
| Refrigerator silent, but not cold | Complete leak or breakdown of the compressor | Diagnostics of the electrical part |
| Frost on one of the shelves | Local leak in the foamed part | Complicated repairs with replacement of the evaporator |
Malfunction of the compressor and start relay
The compressor is the “heart” of the refrigerator, creating pressure for the circulation of the refrigerant. In two-compressor models, different motors are responsible for the refrigeration and freezer compartments. If you have just such a model, then failure of the upper compartment compressor will result in the freezer working perfectly and the refrigerator becoming warm.
In single-compressor models, the situation is more complicated: one motor serves both circuits. If it works, but there is no cold, the problem may not be in the compressor itself, but in start relay or inter-turn short circuit of the windings. The engine may hum, click and try to start, but not develop the required power to pump freon through both circuits.
You can check the operation of the compressor by ear and temperature. During normal operation, it should be warm (but not hot) and produce a uniform hum. If the engine is hot and the pipes are cold, the piston group may have jammed. In this case, replacement of the unit is required.
⚠️ Attention: Attempts to replace the compressor yourself without a vacuum pump and skills in soldering copper pipes are doomed to failure. The entry of moisture or air into the system will instantly disable the new part.
Clogged capillary tube and filter-drier
In the freon circulation system, an important role is played by the capillary tube, which regulates the pressure, and the filter-drier, which cleans the refrigerant from moisture and debris. Over time, especially if there was moisture or oil breakdown products in the system, the filter may become clogged. This creates a “traffic jam” effect: the compressor pumps, but the freon does not pass further than the freezer.
A sign of a blockage is often the characteristic behavior of the condenser temperature. It can only be hot at the point where it exits the compressor, and then cool down. Also, the compressor itself can overheat when operating at maximum loads. In some cases, gurgling or whistling is heard in the filter area.
Removing the blockage requires professional intervention. The technician must:
- 🔹 Drain the remaining freon from the system.
- 🔹 Open the circuit and replace the filter drier with a new one.
- 🔹 Purge the system with nitrogen to remove contaminants.
- 🔹 Evacuate the circuit and fill with new refrigerant.
It is almost impossible to clean the capillary tube yourself without special equipment, since its diameter is a fraction of a millimeter, and any debris inside requires blowing out under high pressure.
Failures in the operation of the thermostat and electronic module
In mechanical refrigerators, the thermostat is responsible for turning the compressor on and off. This is a device with a capillary tube that senses temperature. If the thermostat is stuck in the off position or the thermostat tube has moved and is not in contact with the evaporator, the compressor will not start. In two-compressor models, this will stop only one circuit.
In models with electronic control (for example, Liebherr, Bosch, LG) everything is controlled by the module. It receives data from temperature sensors. If the sensor in the refrigerator compartment fails and transmits false data that it is “already cold” there, the module will not give the command to cool. In this case, the freezer can operate according to its own independent algorithm.
Diagnostics of electronics requires checking the resistance of the sensors. Often the problem is solved by flashing the module or replacing a cheap sensor. However, if the control chip itself has burned out, repairs may not be economically feasible.
☑️ Diagnostics before calling a technician
Violation of the chamber seal and problems with the seal
Sometimes the cause is heat lies not in technology, but in the physics of processes. If the rubber door seal is worn out, dirty, or the door is warped, warm air from the room constantly enters the chamber. The cooling system cannot cope with this flow, and the temperature rises. In a freezer, where the door is opened less often, the cold is retained better.
You can check the tightness with a simple test with a sheet of paper. Clamp the sheet with the door around the perimeter. If it pulls out without resistance or slides easily, the seal does not fit. It is also worth inspecting the door itself for any distortions in the hinges. Heavy food on door shelves can contribute to sagging.
Additionally, frequently opening the door or loading hot food creates excess moisture, which condenses and freezes, exacerbating system problems. No Frost. It is important to ensure that the products do not prevent the door from closing tightly.
⚠️ Attention: If the seal is simply dirty, it can be washed with warm water and soap. If it has lost elasticity and is covered with cracks, only replacement will help. Attempts to soften old rubber with boiling water give a short-term effect.
Frequently asked questions (FAQ)
Is it possible to temporarily use the refrigerator if the top is not cold and the freezer is working?
You cannot use the main compartment for storing perishable foods (meat, milk), since bacteria multiply there. However, you can store vegetables, fruits, unopened canned goods or drinks there that do not require strict temperature conditions. The main thing is not to overload a working freezer.
How long does it take to defrost the refrigerator to remove the ice jam?
To completely defrost the evaporator and drainage system, you need to keep the refrigerator turned off with the doors open for at least 10-12 hours, or better yet, a day. A shorter defrosting may not melt the ice in hard-to-reach places, and the problem will return in a couple of days.
Why, after defrosting, did the refrigerator stop cooling again after a week?
This indicates that defrosting eliminated the symptom (ice jam), but not the cause. Most likely, the defrost heating element, timer or sensor, which should prevent ice formation, is faulty. Diagnostics and replacement of the defective part is required.
Is the appearance of a burning smell dangerous when the refrigerator is operating?
Yes, it is dangerous. A burning smell may indicate overheating of the wiring, a faulty start relay, or an interturn short circuit in the compressor. If such a smell appears, you must immediately disconnect the device from the network and call a specialist.
Can a blockage in the drain tube cause a lack of cold?
The blockage of the drainage itself does not stop the production of cold, but water that has no outlet freezes and builds up an ice lump on the evaporator. Over time, this lump blocks the air supply channels, which leads to the effect of “a working freezer and a warm refrigerator.”