The situation when food turns to stone in the freezer, and room temperature reigns in the main compartment, causes bewilderment among many owners of household appliances. This is a classic symptom that indicates that the cooling system is only partially functioning or is operating with critical heat transfer problems. In most cases, the problem lies not in a breakdown of the compressor itself, which continues to hum, but in a disruption in the circulation of the refrigerant or the operation of the defrosting system.
Understanding the physics of the process helps to quickly find the root of the evil. A refrigeration unit is a closed circuit where freon evaporates and takes away heat. If the freezer is cold, it means that the compressor is pumping, but for some reason the cold does not reach the upper compartment or does not linger there. Impaired air circulation or clogging of the capillary tube are the two most likely scenarios that users encounter. Ignoring the problem can lead to spoilage of products in the main compartment and failure of the motor due to constant wear and tear.
Before calling a technician or looking for spare parts, it is necessary to carry out an initial diagnosis. Often the cause is simply improper operation or an electronics failure, which can be resolved by rebooting. However, if we are talking about mechanical damage to the circuit or deep blockage, more serious intervention measures will be required. It is important to act consistently, checking from simple to complex hypotheses.
Violation of operating rules and overload
The most commonplace, but most common reason is a banal violation of product placement rules. If you have just loaded the main compartment with a large amount of warm food or have packed the shelves tightly, air circulation may have been compromised. In modern models with the system No Frost cold air is blown by a fan from the freezer. If something interferes with the air flow, the temperature in the upper compartment will inevitably rise.
Check whether the food is pressed against the back wall of the refrigerator. In models with a drip defrosting system, there is a cooling evaporator there. Blocking the air supply to it causes the temperature sensor to “think” that the chamber is already cold and turns off the compressor, although the food is still warm. You should also make sure that the door of the main compartment closes tightly and the seal does not allow heat from the outside to pass through.
Particular attention should be paid to the “Super Freeze” mode or similar intensive cooling functions. If this mode was accidentally activated, the refrigerator can work in enhanced mode, freezing everything in the freezer, but due to the redistribution of air flows in the main chamber, it may become warmer than usual or, conversely, everything will freeze, but unevenly. Turn off the special modes and let the equipment return to its normal operating cycle.
Problems with the defrosting system (No Frost)
In refrigerators with a system No Frost the most common cause of the problem described is a malfunction of the defrosting system. The principle of operation is this: the fan drives cold air from the freezer to the refrigerator. If the evaporator in the freezer is overgrown with a “coat” of ice due to the fact that it is not defrosted, the air passage channels are blocked. As a result, there is ice and cold in the freezer, and air simply does not enter the refrigerator.
The key elements here are Defrost heating element, defrost sensor and timer (or electronic control module). If the heating element burns out, the ice does not melt; a block builds up, which blocks the fan. You can hear the fan trying to work, but making noise or cracking as it hits the ice crust. In this case, the freezer works at the limit, and the refrigerator stops cooling.
⚠️ Attention: If you find ice freezing on the back wall of the freezer or in niche behind the plastic panel, this is a direct sign of a malfunction of the defrost system. Operation in this mode leads to overheating of the compressor.
Diagnostics requires testing the elements with a multimeter. The heating element must have a resistance within the normal range (usually several hundred Ohms), the defrost sensor must open the circuit at a certain temperature. Often it is the sensor that fails, which “sticks” in the “cooling in progress” state and does not give a command to turn on the heating to defrost the ice.
How to check the heating element without disassembling the entire refrigerator?
Often the terminals of the heating element can be accessed by removing the bottom panel in the freezer or the back cover. However, for a complete diagnosis, it is better to call a specialist, since partial disassembly of the air ducts will be required.
Refrigerant leakage and system blockage
If the defrosting system is working properly and the products are placed correctly, more serious technical faults should be considered. One of them is freon leak. This can happen through microcracks in the evaporator (especially if you carelessly picked out the ice with a knife) or through corroded sections of the shut-off valves. In case of a partial leak, the amount of refrigerant is enough to freeze ice at the beginning of the circuit (in the freezer), but the gaseous refrigerant simply does not reach the middle of the circuit (refrigerator compartment) or does not have time to evaporate, taking away the heat.
The second option is clogging of the capillary tube. An ice or mud clot may have formed in the system. This often happens due to moisture in the circuit or oil breakdown products. The symptoms are similar to a leak: the freezer is freezing (sometimes too cold), but the refrigerator is warm. In this case, the compressor can work without interruption, trying to gain temperature, and become very hot.
A leak can be diagnosed visually only in the case of obvious swelling of the refrigerator wall (foam insulation rises due to pressure) or the presence of oily stains at the exit of the tubes. In other cases, a manifold is required to check the pressure in the system. It is extremely difficult to eliminate a leak or blockage on your own; the system must be evacuated and charged with freon.
| Symptom | Probable cause | Characteristic symptom |
|---|---|---|
| The freezer is freezing, the refrigerator is warm | Freon leak | The compressor is hot, runs constantly, the wall is swollen |
| Ice in the freezer, there is no cold at the top | Defrost malfunction (No Frost) | The fan is noisy or standing, ice freezing on the evaporator |
| Temperature fluctuates | Clogged capillary tube | Cyclic operation, gurgling in the tubes, condenser overheating |
| The refrigerator is turned off | Thermostat malfunction | The compressor does not start at all, the light is on |
Malfunctions of the thermostat and sensors
In older models of refrigerators, the mechanical one is responsible for turning the compressor on and off. thermostat. If its sensitive element (bellows tube) has moved, lost its seal, or the mechanism itself has failed, the refrigerator may not “understand” that there is heat in the main chamber. It will focus on the temperature in the freezer (if the sensor is there) or simply not turn on the motor, believing that the norm has been reached.
In modern models with electronic control (Full No Frost, Multi Flow), the role of a thermostat is performed by air temperature sensors. There may be several of them: in the refrigerator, in the freezer, on the evaporator. If the sensor in the refrigerator compartment “lies” and shows that it is +2°C, although in fact it is +15°C, the control module will not give the command to cool. In this case, the freezer can operate on its own independent cycle or be cooled by residual cold.
The sensors are checked by measuring their resistance at different temperatures. Often it is enough to briefly warm up the sensor with a hairdryer or cool it down to see changes on the multimeter. It is also worth checking the integrity of the wiring going to the sensors, since under conditions of vibration and temperature changes, the contacts may oxidize or come off.
☑️ Electrical diagnostics
Failure of the compressor and start relay
Although the compressor is the “heart” of the refrigerator, and if it works, it means it is alive, there are situations of partial failure. For example, interturn closure in the windings can lead to the motor humming, but not developing the required power to pump freon throughout the entire circuit. There is only enough pressure for the first section (freezer), and then there is no circulation.
Another element - starting relay. If it is burnt or stuck, the compressor may start with difficulty, hum for several seconds and turn off due to thermal protection. At such moments, the freezer can maintain the temperature by inertia, but the refrigerator no longer cools. You can check the relay by shaking it near your ear: if you hear the ringing of parts inside, most likely it is broken.
⚠️ Attention: Replacing a compressor or starting relay requires skills in working with electricity and refrigerants. Incorrect installation of a new compressor without evacuation of the system will lead to its instant combustion.
Inverter compressors are also worth mentioning. They operate smoothly, regulating power. If the inverter control board fails, the compressor may go into emergency mode at low speeds, which is not enough to fully cool two chambers at the same time.
What to do: action algorithm for the owner
If you are faced with a problem when the freezer is working but the refrigerator is not, do not panic. First, follow simple steps that can help without calling a technician. Complete defrosting of the refrigerator for 10-12 hours (until the ice completely disappears) often solves the problem if the cause was a failure of the defrosting system or “freezing” of the electronics.
After defrosting, turn on the refrigerator without food and listen to the operation. If after a few hours the situation repeats itself, then repairs are required. You should not ignore the problem, hoping that it will “go away on its own.” In the event of a freon leak, running the compressor “dry” (without adequate cooling with oil and freon) will quickly disable it, and repairs will become many times more expensive.
For an accurate diagnosis, it is better to contact a specialized service. The technician will arrive with equipment to check the pressure, the integrity of electrical circuits and the tightness of the circuit. Repairs can range from replacing the sensor (budgetary) to overcooking the circuit and refilling with freon (expensive).
Frequently asked questions (FAQ)
Is it possible to temporarily use a refrigerator if the upper chamber is not cold?
It can be used, but with restrictions. Food in the main compartment will quickly spoil, so store there only what does not require strict temperature conditions (pickles, some vegetables), or transfer perishables to the freezer. Remember that the compressor is overloaded, which reduces its service life.
Why did the refrigerator start to work normally after defrosting, but after a week it stopped working again?
This is a classic sign of a malfunction of the defrost system (the heating element or sensor has burned out) or the presence of moisture in the system, which freezes in the capillary. Defrosting temporarily removes the ice plug, but the cause does not go away, and the ice builds up again.
How much does the repair cost if you need to refill with freon?
The cost consists of the work of the technician, the cost of freon and, possibly, replacing the filter-drier. The price depends on the refrigerator model and the type of refrigerant. The exact amount can only be found out after diagnostics, since it may be necessary to search for a leak.
Does the compressor hum louder than usual with such a malfunction?
Not necessarily. If there is a freon leak or blockage, the compressor may operate quieter or with a changed sound (more ringing), as the load on it changes. However, it often works in normal mode, simply not doing useful cooling work.