Faced with a situation where the refrigerator hisses from the back, many owners of household appliances panic, expecting expensive repairs or a complete replacement of the unit. However, extraneous sounds do not always indicate a critical breakdown or failure of expensive components. Often this is a natural process of refrigerant circulation or the operation of the defrost system, which may be accompanied by a characteristic hissing, gurgling or light whistle.
To accurately determine the source of the problem, you need to listen carefully to the nature of the sound and its localization. Noise from behind can come from the compressor, condenser grid or tubes through which freon moves. In some cases, the sound may be intermittent, appearing only when the engine is turned on or off, and in others it may be constant, intensifying when the door is opened.
In this article, we will examine in detail the main causes of hissing, methods of self-diagnosis, and situations where you can no longer do without calling a technician. Understanding the operating principles of your unit will help you save time and money by avoiding false service calls.
Natural sounds of a working refrigerator
Modern models of refrigerators, whether Indesit, LG or Boschare complex thermodynamic systems. During their normal operation, the refrigerant constantly circulates in a closed circuit. When freon transitions from liquid to gaseous state and back, especially in the area of the evaporator and capillary tube, characteristic hissing or gurgling may occur. These sounds are most often heard from the back side of the unit, where the main communications are located.
In addition, many modern refrigerators are equipped with a system No Frostthat involves forced air circulation. Fans that move cool air through chambers can also create noise, which is sometimes mistaken for hissing. If the sound is uniform, quiet and not accompanied by other alarming symptoms (for example, lack of cold or overheating of the case), then most likely your refrigerator is operating normally.
⚠️ Attention: If the hissing is accompanied by a strong burning smell, plastic or visible smoke, immediately unplug the appliance from the power supply. This may indicate a short circuit or overheating of the wiring.
It is also important to take into account the age of the equipment. New models may make noise during the break-in period while the moving parts of the compressor are grinding in. Old units may begin to hiss due to the accumulation of condensate in the drainage system or changes in the properties of insulating materials.
Problems with the refrigerant and capillary tube
One of the most common reasons why The refrigerator hisses from the backis a violation of the circulation of the refrigerant. If a microcrack or depressurization has formed in the system, freon begins to come out under pressure, creating a characteristic whistling sound. This is the most dangerous scenario, since a refrigerant leak leads to a complete loss of refrigeration capacity and overload of the compressor.
The capillary tube responsible for throttling (pressure reduction) of the refrigerant has a very small diameter. If there is moisture or contamination in the system, a so-called “ice lock” or blockage may occur. As freon passes through a narrow opening under high pressure, it makes a whistle similar to the sound of a flat tire. In such cases compressor it can work continuously, trying to reach the set temperature, but cold does not appear in the chambers.
It is difficult to diagnose a leak or blockage at home, but you can pay attention to the following signs:
- 🔇 Hissing is heard only in certain operating cycles, often before the engine stops.
- 🌡️ The temperature in the main chamber is higher than normal, food begins to deteriorate.
- ❄️ An uneven “coat” or ice forms on the evaporator (in the freezer) only in one corner.
- 🔥 The condenser grille at the back remains cold or barely warm, although the compressor is hot.
If you suspect a leak, under no circumstances try to solder the tubes yourself or add freon without evacuating the system. This requires special equipment and skills.
Danger of self-repairing the circuit
An attempt to solder the tube without removing moisture from the system will lead to the formation of acid inside the circuit, which is guaranteed to cause the compressor to fail within several months.
Malfunctions of the compressor and start relay
The heart of any refrigerator is the compressor. If the refrigerator hisses from the back in the immediate vicinity of the motor, the problem may lie in its mechanical part or in the starting system. Worn valves inside the compressor can leak gas, creating a hissing sound when compressed. A sound can also be produced start relayif its contacts are burnt or the mechanism is stuck.
Often owners confuse hissing with buzzing or vibration. However, if the sound is more like steam escaping, it is worth checking the mounting of the compressor itself. Loose bolts or worn rubber shock absorbers can transmit vibration to the metal tubes and housing, which resonate, creating a hissing or humming sound. In some models, such as Samsung or Atlant, this may be a design feature in a certain position of the unit.
To check the condition of the compressor compartment, follow these steps:
- 🔌 Carefully move the refrigerator away from the wall and remove the rear protective panel (if there is one).
- 👂 Turn on the device and listen to where exactly the sound comes from - from the motor, tubes or grille.
- 🖐️ Carefully (without touching the hot parts!) Check the vibration of the compressor housing by hand.
⚠️ Attention: Before removing the protective panels, be sure to turn off the refrigerator from the mains. Inside the compressor compartment there are live parts under high voltage.
If the hissing comes directly from the compressor housing and is accompanied by its constant humming without shutdowns, this is a sure sign that the unit is working at the limit of its capabilities. In such a situation, professional diagnostics are necessary.
Defrosting system and drainage
In refrigerators with a system No Frost and even in drip models, the defrosting process occurs periodically. At this point, the ice accumulated on the evaporator melts and water flows into a drain tray located above the compressor. When falling on the hot surface of the motor or into water already in the tray, the drops can sizzle like water on a hot frying pan. This sound is absolutely normal and indicates the correct operation of the condensate drainage system.
However, if the drain tube is clogged with debris (food debris, mold or mucus), the water may not have time to drain and overflow, falling on electrical parts or creating gurgling and hissing sounds in hard-to-reach places. Clogged drainage is a common reason why the refrigerator hisses from the back and an unpleasant smell of dampness appears.
The main signs of problems with the drainage system:
- 💧 Water accumulates at the bottom of the refrigerator compartment or under the drawers vegetables.
- 🧊 Excessive ice forms in the freezer, even after defrosting.
- 👃 The appearance of a musty smell from inside the refrigerator.
To clean the drainage hole, you can use a soft wire or a special brush, carefully inserting them into the hole in the back wall of the chamber. Spilling warm water to dissolve the fat plug is also effective.
Comparative table of causes of noise
To systematize the knowledge gained and To quickly identify the cause, use the table below. It will help to compare the nature of the sound with a possible malfunction.
| Character of the sound | Probable cause | Necessary actions | Urgency of repair |
|---|---|---|---|
| Quiet hissing/gurgling | Freon circulation (normal) | Observation | Not required |
| Loud whistle, no cold | Freon leak | Call a technician, look for a leak | High |
| Hissing + water on the floor | Drainage clogged | Cleaning the drainage hole | Medium |
| Hissing when on/off | Thermal expansion/contraction | Checking panel fastening | Not required |
| Motor hissing + humming | Fault compressor | Compressor diagnostics | High |
This table covers the most typical scenarios. However, each refrigerator model, be it Stinol, Liebherr or Haier, may have its own design features that affect the acoustics of operation.
When you need to call a specialist
Despite the possibility of self-diagnosis, there are situations when the intervention of a qualified specialist is inevitable. If the refrigerator hisses from the back and at the same time there are power outages, frequent shutdowns or knocked out plugs, this indicates serious problems with the electrical part of the compressor or wiring.
Also, a technician is needed if after defrosting the refrigerator within 24 hours there is no cold and no sound hissing persists or intensifies. This is a direct sign of a refrigerant leak or compressor failure. Self-repair in these cases is not only ineffective, but also dangerous.
☑️ Signs that you need to call a technician
A professional technician has the necessary equipment: leak detectors, gauge manifolds and vacuum pumps. Only with their help can you accurately determine the location of the leak, replace the filter drier and fill the system with the required amount of freon.
Prevention and care of the refrigerator
If your refrigerator served for a long time and quietly, it is important to follow the operating rules. Regularly, at least once a year, it is recommended to unplug the device, defrost it and wash it thoroughly. Pay special attention to the back wall and the area around the compressor - there should be no clouds of dust that impair heat transfer and cause the motor to work with overload.
Check the tightness of the door seals. If the gum becomes dry or dirty, warm, moist air enters the chamber. This leads to increased ice formation on the evaporator, which during defrosting produces more water and, accordingly, more noise. Wipe the seals with a soft cloth dampened in a mild soap solution.
⚠️ Attention: Do not install the refrigerator close to the wall. For normal operation of the condenser and air circulation, there must be a gap of at least 5-10 cm behind the back wall. Violation of this rule leads to overheating and increased noise.
Following these simple rules will help extend the life of your appliances and maintain silence in the kitchen.
Influence of position refrigerator
If the refrigerator is not level, the compressor may work misaligned, which causes increased wear on the bearings and additional noise. Adjust the legs according to the level.
Why does the refrigerator hiss only at night?
At night, the overall noise level in the apartment decreases, and the sounds of operating equipment become more noticeable. In addition, the refrigerator may work more actively at night if you often opened the door during the day or loaded a lot of warm food. Also at night, the voltage in the network can stabilize, which changes the nature of the compressor operation.
Is hissing dangerous for food?
Hissing itself is not dangerous for food. What's dangerous is what's behind that sound. If this is a freon leak, then the temperature in the chamber will begin to rise and the food may spoil. If the sound is natural, there is no threat to the products. Always monitor the temperature inside the chambers.
Is it okay to have a refrigerator if it hisses?
If the hissing is quiet, intermittent and the refrigerator freezes normally, it’s okay. If the sound is loud, constant, accompanied by heating of the body or lack of cold, it is better to stop operation until the reasons are clarified in order to prevent complete failure of the device.
How long can a refrigerator operate with a freon leak?
Theoretically, the compressor will work constantly, trying to gain temperature. This can last from several hours to several days, but the result is the same - a compressor burned out from overheating. Therefore, if you suspect a leak (hissing + no cold), you cannot delay repairs.