Why the refrigerator does not freeze, but the freezer works: reasons

The situation when there is food in the freezer “petrified”, and in the refrigerator compartment the heat, as in the room, is one of the most common and alarming for owners of household appliances. Double-chamber refrigerators are designed so that the cold is most often produced in the freezer, and then a fan or natural convection redistributes it to the upper chamber. If this balance is disturbed, it almost always indicates a specific malfunction in the refrigerant circulation or control system.

Ignoring the problem in the first hours or days can lead to spoilage of a large amount of food and defrosting of stocks. It is important to understand that modern units, whether Indesit, Atlant or LG, have similar operating principles, but different diagnostic algorithms. In this article, we will analyze the mechanics of the process in detail so that you can understand the essence of the breakdown.

Do not panic and immediately call a technician without checking the basic things. However, if you notice that the compressor works continuously without turning off, or, conversely, is silent, and there is heat inside, this is a signal to action. A critical sign of a serious compressor failure or freon leak is the complete absence of cold in both compartments after the equipment has completely defrosted for 24 hours.

The principle of operation of two-chamber cooling systems

To understand why a temperature imbalance occurs, you need to understand the basic physics of the process. Most modern models use single-circuit system cooling. This means that the refrigerant (freon) circulates in a single closed circle, passing first through the freezer chamber, where it boils and takes away heat, and then through the refrigeration compartment.

In systems No Frost a special fan is responsible for the distribution of cold. It forces cooled air from the freezer into the upper compartment through special channels. If the fan stops or the ducts become clogged with ice, the cold stops flowing upward, although the temperature in the freezer remains low. In drip systems (crying evaporator), the cold is transmitted through the back wall, and a violation here is often associated with a gas leak.

There are also dual-circuit systems, where each chamber is responsible for its own independent evaporator and its own circulation circuit. In such models, for example, some series Bosch or Siemens, the problem can be localized strictly in one circuit. However, statistically more common are single-circuit units, where the breakdown of one element affects the operation of the entire system.

⚠️ Attention: Attempts to independently open sealed parts of the circuit or change the compressor without special equipment and skills are strictly prohibited. This is life-threatening and requires a license to work with freons.

Refrigerant leakage: the most common cause

If you find that the refrigerator has stopped freezing, but the freezer still holds the temperature (or has also started to get warmer), there is an 80% chance that it happened freon leak. Freon is a working fluid that circulates inside the tubes. The circuit is sealed, but over time the metal corrodes, or microcracks appear in the soldering areas, especially if the refrigerator has been moved frequently.

When there is a leak, the amount of gas in the system decreases. The compressor tries to compensate for the lack of cold and works non-stop, humming louder than usual. However, due to low pressure, the refrigerant simply does not have time to cool the entire volume of the evaporator. First, the cold disappears in the most distant point - the refrigerator compartment, and the freezer, located closer to the compressor, maintains a subzero temperature for some time.

It is almost impossible to diagnose a leak visually, since the gas is colorless and odorless. The technician uses a leak detector or water immersion method (for removed components) to find the location of the damage. After eliminating the hole, the system is evacuated and filled with a new volume of gas.

Often the leak occurs in the foamed housing, in the so-called “crying” evaporator, which is built into the rear wall of the refrigerator compartment. If the tubes are rotten inside the polyurethane foam, repair may not be economically feasible, as it requires replacing the entire box or installing an external evaporator.

Signs indicating a leak:

• 🔥 The compressor runs continuously without shutting off and is very hot to the touch.
• 🧊 In the freezer, the food thaws, and in the refrigerator compartment it is warm.
• 🔇 The unit turns on, hums for a couple of seconds and turns off (if the leak is critical and the protection has worked).
• 💧 On the rear radiator grille (condenser) there are no characteristic warm and cold zones; all at the same temperature or cold.

⚠️ Attention: If you smell burnt wiring or rubber while the compressor is running, immediately unplug the device. This may indicate overheating of the motor due to idling with low freon pressure.

Clogged capillary tube

The second most common reason that the refrigerator does not cool is clogged capillary tube. The capillary is a very thin copper tube that connects the condenser and the evaporator. It is here that a sharp drop in freon pressure occurs, which allows it to boil and cool. The diameter of the tube is so small that even a microscopic particle of debris remaining after installation, or oil breakdown products can block the flow of refrigerant.

If clogged, freon cannot circulate in full. The compressor pumps gas, but it gets stuck in front of the plug. The discharge pressure increases and the suction pressure decreases. As a result, little refrigerant enters the evaporator (freezer and refrigerator). The symptoms are very similar to a leak: the freezer is still slightly cold, but the refrigerator compartment is warm.

Only a specialist can distinguish a clog from a leak by the nature of the compressor noise and the pressure in the system. When clogged, the compressor often runs quieter than usual or makes a peculiar gurgling noise because it is difficult for it to push gas through the plug. There may also be swelling of the side walls of the housing due to overheating of the condenser tubes foamed in the walls.

Removing the blockage requires professional purging of the system with nitrogen under high pressure. In difficult cases, you have to cut out a piece of the tube and solder in a new filter-drier, which should trap debris, but sometimes allows it to pass further.

Main symptoms of blockage:

• 🔊 The compressor is overloaded and can become very hot.
• 📉 The suction pressure is below normal, discharge - above normal.
• 🧊 The evaporator in the freezer is only partially or not completely covered with frost.
• 🛑 After turning it off and on again, the refrigerator may begin to freeze for a short time until the gas “breaks through” the blockage again.

Faults in the defrost system (for No Frost)

If you have a refrigerator with a system No Frost, and it has stopped freezing in the upper compartment, while a huge “coat” of ice has formed in the freezer, the problem lies in the defrost system. Ice builds up on the evaporator (which is hidden behind a plastic panel in the freezer) and blocks the channels through which the fan should drive cold air into the refrigerator compartment.

In normal mode, a special one turns on several times a day and melts the ice on the evaporator. The water flows into the drainage tray. If the heating element is burnt out, or the defrost sensor is faulty, or the timer (electronic module) does not give a command to heat, ice grows uncontrollably. Sooner or later, it turns into a monolithic piece through which air does not pass. Defrost heating element turns on several times a day and melts the ice on the evaporator. The water flows into the drainage tray. If the heating element is burnt out, or the defrost sensor is faulty, or the timer (electronic module) does not give a command to heat, ice grows uncontrollably. Sooner or later it turns into a monolithic piece through which air does not pass.

As a result, the fan hums and spins, but the air does not circulate. It becomes warmer in the freezer, but the food is still held due to its proximity to the ice block, and the refrigerator compartment becomes warm. Often, you can hear the fan hitting the frozen ice with its blades, making a cracking noise.

For diagnostics, you need to completely defrost the refrigerator (at least 24 hours, preferably 48). If, after turning it on, it starts to freeze normally in both compartments, but after 1-2 weeks the problem returns, it means that the defrosting system is faulty. It is necessary to change the heating element, sensors or timer.