The situation when the food in the freezer is securely frozen, but in the main part of the refrigerator the milk has turned sour or the cucumbers have become limp - this is a classic symptom of serious problems. Many users mistakenly believe that if the compressor hums and freezes below, then the equipment is working properly, but this is not the case. In two-chamber models, the cold is distributed unevenly, and the lack of cooling in the upper section while the bottom is running indicates a specific range of problems that require immediate attention.
First, you need to understand the principle of operation of your model. In systems No Frost cold air is forced by a fan from the freezer into the refrigeration compartment through special channels. If circulation is disrupted, the upper chamber will remain warm. In drip systems ("crying back"), the evaporator is hidden behind the back wall, and the problems often lie in a refrigerant leak or a malfunctioning thermostat. Ignoring the problem will lead to spoilage of products and failure of the compressor due to operation in enhanced mode.
The first thing to do is to carry out initial diagnostics without disassembling the unit. Check to see if the air ducts are blocked by food, if the light comes on when the door is closed, and if the refrigerator is too tightly packed. Sometimes the reason is simple: a tight rubber band on the door prevents it from closing completely, or the door closing sensor is stuck. If visually everything is in order, and the temperature in the upper compartment rises above +10°C, you will have to look deeper.
Impaired air circulation in the No Frost system
In refrigerators with technology No Frost the main cause of warm air in the upper compartment is the impaired circulation of air flows. The evaporator in such models is located in the freezer, and the fan drives the cold into the refrigerator compartment. If the fan has stopped or the ducts are clogged with ice, the cold simply does not reach the upper shelves. This is one of the most common reasons why freezer works, but the refrigerator does not.
Often the problem lies in the defrosting system. If Defrost heating element the timer burns out or fails, a “fur coat” grows on the evaporator, which blocks the air supply channels. The fan may even hum, but the air will not pass through the ice plug. As a result, the freezer will be minus 18-24°C, and the temperature on the top shelf of the refrigerator will be above zero.
For diagnostics, you need to defrost the refrigerator completely (at least 24 hours with the doors open). If after defrosting the unit worked normally for a day or two, and then the problem recurred, it means the defrosting system is faulty. You will need to use a multimeter to check the heating element, defrost sensor and fuse.
- ❄️ Check the operation of the fan: when the freezer door is open, it should stop, when closed, it should start.
- 🧊 Inspect the air ducts: there are no foreign objects or ice plugs there.
- 🔌 Ring the defrost heating element: the resistance should be within normal limits, a break indicates the need for replacement.
⚠️ Attention: If you hear that the fan is humming but not spinning, it may be jammed with ice or the bushing is faulty. An attempt to start it by force may lead to burnout of the motor winding.
It is also important to check the temperature regulator damper. In some models Indesit or Ariston the damper is controlled by a mechanical thermostat or an electronic module. If it is stuck in the closed position, cold air will physically not be able to enter the refrigerator compartment, even if the defrost system is working properly.
Freon leakage: signs and consequences
When a refrigerant leak occurs in the cooling circuit, those parts of the system that are located further from the compressor are the first to stop receiving cold. In most two-compartment refrigerators, the circuit is designed so that freon first passes through the evaporator of the freezer compartment, and then through the evaporator of the refrigerator compartment. Therefore, if 30-50% of freon is lost, the freezer can still freeze, but the top is already warm.
It is difficult to visually diagnose a leak, since the gas is colorless and odorless. However, there are indirect signs. The compressor starts working almost without interruption, trying to gain temperature. On the rear grille (condenser), you may notice that it is heated unevenly: only part of the tubes is hot, while the rest remain cold or slightly warm.
If you find oily spots under the refrigerator or on the evaporator tubes inside the chambers, this is a sure sign of depressurization. In places of leakage, the oil circulating along with freon begins to flow out. Finding the location of the fistula on your own without a leak detector is almost impossible, especially if the tubes are foamed in the housing.
- 🔇 The compressor hums continuously, without shutdown cycles.
- 🌡️ The condenser grill is partially heated or completely cold.
- 💧 Availability oil leaks in the compressor area or inside the chambers.
Independent refilling of the refrigerator with freon is impossible without special tools (vacuum pump, pressure gauge station, scales). Moreover, before refueling, it is necessary to find and repair the leak, otherwise the gas will come out again in a few days or weeks.
⚠️ Attention: Do not try to simply “add gas”. Different types of freon (R134a, R600a) require different oils. Mixing oils or types of refrigerant will lead to blockage of the capillary system and costly repairs.
In models with crying evaporator leakage often occurs in the foamed part of the housing (internal circuit). Repair in this case is complicated: either the evaporator is rebalanced, taking it outside (which spoils the view), or the housing is opened. In budget models, this is often considered unprofitable.
Faults of the compressor and start relay
The compressor is the heart of the refrigerator, and its incorrect operation can lead to paradoxical phenomena. If the power of the compressor has dropped (wear of the valve group), it can create sufficient pressure to cool the freezer, but there is no longer enough strength to push freon through the entire circuit to the refrigerator compartment. In this case, the unit hums and heats up, but there is no cold at the top.
A frequent reason for the compressor stopping is a malfunction of the start-up relay. This small element, placed on the side or bottom of the compressor, provides the impulse to start the motor. If the relay is stuck or burnt out, the compressor will either hum and click while trying to start, or remain silent. In some cases, the relay may allow starting, but immediately turn off the motor due to a false operation of the protection.
To check the relay, you need to remove it and shake it: if you hear a ringing inside (as from broken ceramics or a broken tongue), the part is faulty. Also, blackening of the contacts inside the relay indicates overheating. Replacing the relay is a simple procedure available to any home handyman, and often solves the problem of “won’t start” or “works jerkily.”
☑️ Compressor diagnostics
If the compressor is hot, the relay is working, but there is no cold nowhere or only in the freezer - there is a high probability of an interturn short circuit in the windings or critical wear of the piston group. In this case, the entire compressor needs to be replaced.
Problems with the thermostat and sensors
In older models of refrigerators (for example, Biryusa, old Atlanta) a mechanical thermostat is responsible for the temperature. This is a device with a capillary tube that is inserted into the evaporator. If the thermostat is stuck in the "Off" position or its contacts are burnt, the compressor will not receive a command to turn on. However, if there is only one thermostat for two chambers and it is in the refrigerator compartment, then if it malfunctions, the refrigerator may behave strangely.
In modern electronic models (Samsung, LG, Bosch) the role of a thermostat is performed by temperature sensors (NTC thermistors). There are usually several of them: in the refrigerator, in the freezer, on the evaporator. If the sensor in the refrigerator compartment lies and shows the module that it is already -5°C, although in fact it is +10°C, the “brains” of the refrigerator will not turn on the compressor or fan. In this case, the freezer can freeze based on residual cold or according to the readings of its own sensor.
You can check the sensor with a multimeter, measuring its resistance at different temperatures (for example, taking it out of the freezer and warming it in your hand). The resistance should change smoothly. If the device shows a break or zero, the sensor needs to be replaced.
| Symptom | Probable cause | Action |
|---|---|---|
| The compressor does not turn on at all | The thermostat or module is faulty controls | Close the thermostat contacts to check |
| The refrigerator does not turn off | Freon leak or thermostat stuck | Check the pressure, replace the sensor |
| Freezer freezing, the top is warm | Capillary clogged or leaking | You need to call a technician with equipment |
| Temperature jumps | Faulty NTC sensor | Replace the sensor temperature |
It is important to consider that in two-compressor refrigerators, each chamber has its own motor-compressor. If you have just such a model, and the refrigerator compartment does not work, it means that it is the upper compressor or its thermostat that has failed, and the lower one (freezer) is working properly. This simplifies diagnostics: the problem is localized in one circuit.
Clogged capillary tube
The capillary tube is a thin copper channel in which throttling (sharp expansion) of freon occurs, which causes cooling. The diameter of this channel is extremely small, so it is sensitive to any contamination. Ice plugs may form in the system (due to moisture in the freon) or blockages from oil and metal oxidation products.
If the capillary is clogged, the circulation of the refrigerant is disrupted. The compressor tries to push the gas, the pressure at the outlet increases and the pressure at the inlet drops. As a result, the evaporator in the refrigerator compartment (which is further downstream) stops cooling, while the area before the blockage (often in the freezer or near the compressor) may be cold or covered with frost.
It is difficult to diagnose a blockage at home. A characteristic sign is that when the compressor is operating, the filter-drier (barrel near the compressor) may be warm, and the tubes after it may be cold, or a characteristic hissing/gurgling sound can be heard, which should not be normal.
Removing the blockage requires professional purging of the system with nitrogen under high pressure, replacing the filter-drier and vacuuming. Simply “shaking” the refrigerator or knocking on the pipes will not help - this is only a temporary measure that can kill the compressor.
⚠️ Attention: Never break through blockages by piercing the pipes or using aggressive chemicals. This is guaranteed to lead to moisture and dirt getting into the system, which will require a complete overhaul of the refrigerator.
The influence of the environment and improper operation
Sometimes the reason that the refrigerator compartment does not work lies not in the breakdown, but in the operating conditions. Refrigerators of climate class SN-ST (subnormal-subtropical) are not intended for operation in unheated rooms at temperatures below +10°C. If you take the old refrigerator out onto the balcony “to store pickles” in winter, it may stop freezing in the upper compartment or may not turn on at all, since the thermostat in a warm room “seems” to be cold anyway.
The location of the unit also plays an important role. If the refrigerator is located close to the wall or in a niche without gaps, the condenser does not have time to give off heat. The compressor overheats and goes into protection mode, not having time to freeze the entire volume of the chambers. This is especially critical in the summer.
Overfilling the chambers with products also disrupts circulation. If you plug all the vents with food or pack the shelves tightly so that air doesn't move, different corners of the refrigerator will have different temperatures. It may be warm in the far corners of the upper shelves, while everything is frozen at the back wall.
In addition, frequent opening of the door or a loose seal (elastic band) leads to a constant influx of warm, moist air. The defrost system cannot cope with the volume of ice, the channels become overgrown, and the cooling efficiency decreases. Check the tightness of the door with a sheet of paper: clamp it around the perimeter of the closed door - it should be removed with force.
When you need to call a technician
Independent repair is possible only in cases of replacing the thermostat, start relay, fan or temperature sensors. These parts are readily available and require minimal tools. However, there are situations when you cannot do without a specialist and his equipment.
If a freon leak is diagnosed, soldering of pipes, evacuation of the system and accurate charging of refrigerant by scale are required. Violation of the filling technology (for example, filling “by eye” or without a vacuum sealer) will lead to the fact that after a month or two the refrigerator will stop freezing again, and the compressor will burn out due to lack of cooling or water hammer with liquid freon.
A technician is also needed if the problem is in the electronic control module. Repairing a board requires circuit knowledge and soldering of small components. An attempt to replace the entire module is often not economically feasible, since a new board can cost half the price of a new refrigerator.
- 🛠️ Soldering of copper tubes and working with gas is required.
- 🔋 The electronic control module is faulty (burnt tracks, swollen capacitors).
- 🔍 Professional diagnostics with a leak detector and pressure gauges are required.
Remember that a modern refrigerator is a complex unit where the mechanical part is closely connected with electronics. Correct diagnostics saves money: replacing a compressor with a simple freon leak (which is often done by unqualified technicians “just to be sure”) is a waste of your money.
Frequently asked questions (FAQ)
Why does the refrigerator turn on for 1 minute and turn off instead of freezing?
Most likely, the compressor thermal protection relay is triggered. Reasons: the starting relay is faulty (cannot start the engine), low voltage in the network, or the compressor is jammed. A short circuit in the windings is also possible.
Is it possible to use a refrigerator if one chamber does not work?
Short-term - yes, but food in a warm chamber will spoil. Long-term operation in this mode is harmful to the compressor, which will work without rest, trying to reach an unattainable temperature. It is better to turn off the device before repair.
How much does it cost to repair if the cold in the refrigerator compartment is gone?
The price depends on the breakdown. Replacing a thermostat or sensor is inexpensive. Refilling with freon and finding leaks is an average cost. Replacing the compressor is the most expensive option. The technician will tell you the exact amount after diagnostics.
Why is there a lot of ice on the back wall of the refrigerator, but no cold?
This is a sign of a malfunction of the defrosting system (the heating element, timer or sensor has burned out) in No Frost models, or a violation of the door seal in drip models. Ice blocks heat transfer.
How to defrost a refrigerator correctly if it has stopped freezing?
Unplug, remove all food, open the doors. Leave for 24 hours. Place rags to catch water. Do not use a hairdryer or a knife to chip ice - you can damage the evaporator and cause a freon leak.