The situation when it is warm, food begins to deteriorate, and refrigerator compartment warm, food begins to spoil, and freezer continues to work normally and freezes water, is one of the most common complaints of owners household appliances. This behavior of the unit often takes you by surprise, because visually the compressor is humming, the light is on, but there is no expected cold on the shelves. This condition indicates a refrigerant circulation problem or a malfunction in the temperature control system.
Ignoring the problem at an early stage can lead to failure of an expensive compressor or a complete leak of freon, which will require major repairs. Understanding the principles of operation two-chamber systems will help you quickly diagnose a breakdown and make a decision: call a technician or try to fix the fault yourself. In this article we will analyze in detail the main causes of temperature imbalance.
The first thing you need to do is listen to the operation of the motor. If it runs continuously without turning off for hours, this is a sure sign that the system cannot achieve the specified parameters. At the same time, if the unit is silent, but there is ice in the freezer, perhaps the problem lies in the electronics or the start relay. Let's look at the main components responsible for the distribution of cold.
⚠️ Attention: If you smell burning or see sparking in the compressor area, immediately disconnect the device from the power supply. Operation of faulty equipment can lead to a short circuit or fire.
Malfunction of the thermostat or temperature sensor
The most likely reason that the refrigerator does not freeze in the main compartment is the failure of the thermostat. This component is responsible for turning the compressor on and off, based on the temperature inside the chambers. Older models use a mechanical thermostat with a bellows tube, which, when cooled, contracts and opens the contacts. If the tube has lost its tightness or the contacts have oxidized, the compressor simply will not receive a signal to start.
In modern models with a system No Frost or electronic control, the role of a thermostat is performed by air sensors. They are located inside the cameras and transmit data to the control module. If the sensor “lies” and shows that the chamber is already colder than it actually is, the compressor will not turn on. However, if the freezer is working, this may indicate the presence of a separate sensor for it, which is working, while the refrigerator compartment sensor is faulty.
Diagnostics of a mechanical thermostat is possible at home with a multimeter. It is necessary to remove the regulator, disconnect the wires and “ring” the contacts. When warm, the circuit should be closed. For electronic sensors, checking is more difficult and often requires replacement with a known-good test element.
- ❄️ A mechanical thermostat most often fails due to natural wear of the contacts or damage to the capillary tube.
- 📉 An electronic sensor may fail due to voltage surges or moisture on the contacts.
- 🔧 Replacing the thermostat is one of the most common and inexpensive procedures when repairing refrigerators.
It is worth noting that in some models, for example Indesit or Atlant, the thermostat is located inside the chamber and is covered with a plastic cover. Replacing it requires care so as not to damage the door seal. If after replacing the part the situation has not changed, the problem lies deeper.
⚠️ Attention: Before replacing the thermostat, be sure to wait until the unit has completely defrosted (at least 24 hours) if diagnostics were carried out with the compressor on. Working with electricians in condensation conditions is dangerous.
Problems with defrosting in No Frost systems
If your refrigerator equipped with a No Frost system, then the most common reason for the lack of cold in the upper compartment is a malfunction of the defrost system. In such units, cold air is forced by a fan from the freezer into the refrigerator through special channels. Over time, an ice “coat” forms on the evaporator. In normal mode, it periodically melts, but if the defrosting system is broken, the ice freezes and tightly blocks the air supply channels.
As a result, the fan hums, the compressor works, but cold air physically cannot get into the main compartment. The freezer continues to freeze, since the evaporator is located there. You may notice that the back wall in the refrigerator compartment is covered with frost or, on the contrary, has become warm, and a barely noticeable flow is blowing from the air ducts.
The defrost system consists of three main elements: a heater (heating element), a defrost sensor and a timer (or electronic module). If the heating element burns out, the ice does not melt. If the sensor is faulty, it does not give a command to turn on the heating or, conversely, does not turn it off. The timer may simply “stick” in the cooling mode, without switching to the defrosting mode.
☑️ Diagnostics of the defrost system
For diagnostics, you need to get to the evaporator by removing the back panel in the freezer. Visually assess the amount of ice. If the evaporator has turned into a monolithic piece of ice and the channels are clogged, the diagnosis is obvious. Defrost the refrigerator within 24 hours. If after switching on it worked normally, but after 2-3 weeks the problem recurred, it means that one of the elements of the defrost system requires replacement.
Refrigerant leak and capillary system clogging
A more serious technical malfunction, due to which The fridge compartment does not freezeis a freon leak or capillary system clogging tubes. The refrigerant circulates in a closed circuit, picking up heat. If its quantity decreases due to a microcrack in the circuit (often in the foamed part of the housing or in the evaporator), the pressure is not enough to cool the entire volume. First of all, the cold stops flowing into the upper chamber, since the refrigerant simply does not reach it in the required state.
Clogging of the capillary tube occurs less frequently, usually due to moisture entering the system or oil oxidation products. At the point where the tube narrows, an ice or paraffin plug forms, blocking circulation. The symptoms are similar to a leak: the compressor runs continuously, trying to raise the temperature, but there is no effect. The freezer may freeze weaker than usual or only at the back wall.
It is almost impossible to diagnose a leak or blockage yourself without special equipment. Craftsmen use leak detectors, pressure gauge stations and nitrogen for pressure testing. If, when the compressor is operating, the condenser (grid at the back) is only partially warm or cold, and the filter drier is at room temperature, these are signs of circulation problems.
| Symptom | Probable cause | Characteristic symptom |
|---|---|---|
| Compressor hums, but does not start | Stuck compressor or start relay | Relay clicks, motor housing overheating |
| The refrigerator freezes, but does not turn off | Freon leak or blockage | Warm condenser, no cold in the upper chamber |
| Warm in the chamber, ice in the freezer | Malfunction of the defrost system (No Frost) | Ice coat on the evaporator, clogged channels |
| Periodic on/off | Thermostat malfunction | The temperature in the chamber does not correspond to the settings |
Repair in case of a leak or blockage involves a complex process: finding the location of the damage, soldering, replacing the filter-drier and refilling new freon. This is a job for a qualified, licensed professional. Independent attempts to refuel can permanently damage the compressor.
Is it possible to refuel the refrigerator yourself?
Theoretically, it is possible if you have the equipment and skills. However, without vacuuming the system (removing moisture and air), the compressor will not last long. In addition, different types of freon (R134a, R600a) require different oils and procedures. R600a is also explosive. It’s better not to take risks.
Faults of the compressor and start relay
The compressor is the heart refrigerator. If it does not work correctly, the entire thermodynamics of the process is disrupted. It often happens that the engine hums, but does not start, or starts for a few seconds and stalls. In this case, the start relay is to blame. It supplies the initial impulse to the motor winding. If the relay contacts are burnt or the coil is burned out, the compressor cannot gain speed.
In more severe cases, the compressor itself loses performance. The piston group wears out, the valves stick or break. In this state, it can create some kind of pressure sufficient to operate the freezer (which is closer to the outlet of the compressor in some circuits or requires less cold to maintain -18°C), but not enough to cool a large volume of the refrigeration chamber.
You can check the start relay visually (for any burning or smell) and by ringing. Replacing this part is simple and inexpensive. If the problem is in the motor-compressor itself, replacing it is economically feasible only for new or expensive models. In older units it is easier to buy a new refrigerator.
- 🔊 A loud knock or clanging when starting the compressor often indicates mechanical destruction of the internal components.
- 🔥 Strong heating of the compressor housing (impossible to touch with your hand) indicates an overload or an interturn short circuit.
- ⚡ Frequent knocking out of plugs or machines when turning on the refrigerator is a sign of a short circuit in the motor windings.
It is important to distinguish between the operating noise of the compressor and the emergency hum. Normal operation is accompanied by a steady hum. If the sound changes to intermittent, whistling or is accompanied by vibration of the case, this is an alarming signal.
⚠️ Attention: When replacing the compressor or start relay in refrigerators with R600a (isobutane) refrigerant, it is strictly forbidden to use an open flame for soldering. This gas is explosive. The use of a burner with gas exhaust or special clamps is required.
The influence of the operating mode and external factors
The reason that The refrigerator does not freeze wellis not always due to a breakdown. Sometimes external factors or improper operation are to blame. For example, if the refrigerator is located close to the wall or in a niche without gaps for ventilation, the condenser will not have time to give off heat. The compressor overheats and goes into protection without having time to freeze the chambers.
It is also worth checking the settings. In modern electronically controlled models (LG, Samsung, Bosch), the user could accidentally activate the “Super Freeze” mode only for the freezer or reset the temperature zone settings. Check the display to see if the alarm indicator or defrost symbol is on.
Another banal but important factor is the loading density. If you have just placed a large amount of warm food into the chamber, or if you have packed the shelves tightly, preventing air circulation (especially in No Frost systems), the cold will not be able to be evenly distributed. The fan will circulate air, but it will get stuck in the “pockets.”
Check the integrity of the rubber seals on the doors. If the rubber is dry, dirty, or the door is warped, warm air constantly enters the chamber. The compressor will work hard, trying to compensate for the heat gain, but in the refrigerator compartment the temperature will still be higher than normal, while the freezer, whose door is opened less often, will keep the cold.
Specifics of single-compressor and double-compressor systems
Understanding the design of your unit is critical for diagnosis. B single-compressor models one motor drives freon along both circuits. Typically, the freezer compartment is cooled first, and then, according to the residual principle, the cold enters the refrigerator compartment. Therefore, if there is a lack of freon or weak compression, it is the upper compartment that suffers first.
In two-compressor refrigerators the situation is different. There are two independent motors and two circuits. If you have just such a model (often found in the premium segment or old Soviet Saratovs), and only the fridge compartment does not work, then the problem is localized strictly in the circuit of this chamber: its thermostat, its sensor, or a leak in its evaporator. In this case, the freezer can work perfectly, since it has its own independent system.
There are also models with one compressor, but two circuits and a solenoid valve that switches freon flows. If the valve jams in the “freezer” position, then freon does not flow into the upper chamber. This is a common malfunction in equipment Indesit i Ariston. The valve requires replacement.
Frequently asked questions (FAQ)
Is it possible to temporarily use a refrigerator if it does not work upper chamber?
Can be used, but not for long. Food in the refrigerator compartment will quickly spoil. In addition, if the cause is a freon leak, the compressor will work without stopping, which will lead to its overheating and eventual breakdown. If the reason is in the thermostat, the risk is less, but the food will still be lost. It is better to eliminate the malfunction.
Why did the refrigerator start working after defrosting, but after a week it stopped again?
This is a classic sign of a malfunction of the defrost system (in No Frost models). The ice froze again and blocked the channels. You need to replace the defrost heating element, defrost sensor or timer. Simply defrosting the refrigerator every week is not a solution to the problem, it is only a temporary measure.
How much does it cost to repair if the cold in the refrigerator compartment has disappeared?
The cost depends on the reason. Replacing the thermostat or start relay is an inexpensive procedure. Freon refilling and leak detection are more expensive. Replacing the compressor is the most expensive part. The exact price can only be given after diagnostics by a technician on site.
Can a clogged filter-drier be the cause of the problem?
Yes, the filter-drier can become clogged with oxidation products or moisture, creating a blockage. This disrupts the circulation of freon. The symptoms are similar to a leak: the compressor works, but there is no cold. The filter needs to be replaced and the system evacuated.
What to do if the refrigerator is humming, but does not freeze anywhere?
If it does not freeze anywhere (neither in the freezer nor in the refrigerator), then the reason is most likely in the compressor itself (does not start, the winding is burned out) or the complete absence of freon. It is also worth checking the presence of voltage in the network and the integrity of the power cord.