The sudden appearance of an extraneous sound in the operation of household appliances always causes concern. The refrigerator makes a hissing sound is a signal that cannot be ignored, although you should not panic ahead of time either. In some cases, this is a natural physical process associated with the circulation of the refrigerant, and in others it is a sign of a serious malfunction that requires the intervention of a technician.
Understanding the nature of the occurrence of sounds allows the owner of the unit to quickly navigate the situation. Hissing can come from different components: a compressor, a pipe system, or even a drainage system. Modern models They often have more complex operating acoustics than old Soviet models, which confuses inexperienced users.
In this article we will analyze in detail all the possible causes of hissing sounds. You will learn to distinguish the normal operation of equipment from critical breakdowns that can lead to spoilage of products or failure of expensive components. Diagnostics starts with careful listening and visual inspection.
Natural sounds: when hissing is the norm
Many owners get scared when they hear strange sounds immediately after purchasing new equipment. However refrigerant, moving through the tube system, it often makes a gurgling, whistling or light hissing sound. This occurs due to changes in the pressure and state of aggregation of freon during the transition from liquid to gaseous state.
Such sounds are heard especially often in models with a system No Frost or drip defrosting. When the compressor starts or immediately after it stops, the pressure in the circuit is equalized and the gas passes through the capillary tube with a characteristic sound. If the sound is quiet, periodic and not accompanied by other symptoms, this is normal operation.
⚠️ Attention: A hissing sound lasting from a few seconds to a couple of minutes, occurring cyclically, is considered normal. If the sound does not stop for hours, it is necessary to carry out diagnostics.
It is also important to take into account the acoustic properties of materials. The plastic housing or internal shelves may resonate with the vibration of the compressor, amplifying the natural sounds of the system. Check whether the refrigerator body is touching a wall or furniture, as vibration transmission can distort the sound, making it sound like a hissing.
Faults in the compressor and start relay
If the hissing comes directly from the compressor motor, the situation may be more serious. This often indicates that compressor cannot start or is overloaded. The starting relay, responsible for starting the engine, may click and hiss, trying to start the piston group, but to no avail.
In such cases, the engine hums, then there is a click, a short hiss and the unit goes silent. After some time, the cycle repeats. This is a classic symptom of a compressor “jamming” or winding failure. Operating equipment in this mode is strictly prohibitedas this can lead to complete combustion of the motor.
Another reason may be depressurization of the pipes coming from the compressor. If a microscopic fistula has formed somewhere, gas will escape under pressure, creating a characteristic whistling sound. Visually, this is often accompanied by oily spots at the bottom of the unit.
Is it possible to start a refrigerator without a start relay?
Starting a compressor without a start relay is possible only in emergency cases and requires professional skills. This is a temporary measure, since operation without protection will lead to rapid overheating and burning of the motor windings.
Problems with the defrosting system and drainage
In refrigerators with automatic defrosting, hissing is often associated with water getting on hot elements. When turned on Defrost heating elementit heats up to a high temperature. If a lot of water or ice has accumulated in the evaporator tray, upon contact with a hot heater it instantly boils and evaporates, making a sound similar to frying meat in a frying pan.
This phenomenon is often observed in winter or at high humidity in the room. Water flows down the drainage channel, but does not have time to evaporate evenly. A clogged drain hole can also lead to gurgling and hissing as air passes through the water plug in the tube.
To test this theory, just look into the freezer compartment (if the system No Frost) or into the lower part of the back wall (in drip models). The presence of ice or puddles under the refrigerator will confirm a problem with the removal or evaporation of moisture.
☑️ Checking the water drainage system
Refrigerant leak as a cause of noise
One of the most unpleasant causes of hissing is freon leak. If there is a crack or hole in the circuit, gas under pressure escapes, creating a whistling sound. Unlike natural gurgling, the sound of a leak is usually more monotonous and can be heard constantly until the pressure in the system equals atmospheric pressure.
A leak can be determined not only by sound. Indirect signs are: insufficient cooling of the chambers, operation of the compressor without stopping, lack of freezing of the evaporator or, conversely, the formation of a “snow coat” in one corner. Also, traces of oil are often visible at the leak site, since freon circulates along with the compressor oil.
It is difficult to find the leak site on your own, since the refrigerant can escape through microcracks in the foamed parts of the housing or in places where pipes are soldered, hidden by insulation. Using soapy water to look for bubbles is an old method that only works if there is obvious damage to the external tubes.
⚠️ Warning: Freon itself can be dangerous in high concentrations in a confined space, although modern types (R600a) are also explosive. If you suspect a leak, ensure the room is ventilated.
Diagnostics: table of symptoms and solutions
To simplify the process of identifying a malfunction, use the summary table. It will help to compare the nature of the sound with the probable cause and the necessary actions.
| The nature of the sound | Localization | Probable cause | Necessary actions |
|---|---|---|---|
| Short-term hissing | Inside the chambers, along the entire height | Refrigerant circulation | Observation, no repair needed |
| Hissing with clicks | Bottom part, rear | Malfunction of the start relay | Replacing the relay or compressor |
| Hissing as if frying | Rear wall, bottom | Water ingress on Heating element | Cleaning drainage, checking defrost |
| Constant whistle | Any part of the circuit | Freon leakage | Searching for leaks, refilling, soldering |
Use this table as a primary guide. However, an accurate diagnosis can only be made by a specialist using a pressure gauge manifold and a leak detector. Self-disassembly of components under pressure without skills can aggravate the situation.
Consequences of ignoring the problem
If the refrigerator makes a hissing sound due to a malfunction, ignoring this signal leads to negative consequences. In the case of a freon leak, the compressor will work hard, trying to reach the set temperature. This will lead to its overheating and eventual combustion, which will significantly increase the cost of repairs.
If there are problems with defrosting, water can get on the electrical contacts or flood the floor, causing a short circuit or damage to the floor covering. In winter, frozen condensate can rupture the plastic elements of the drainage system.
Timely contacting a specialist allows you to eliminate the problem at an early stage. Replacing a lance sensor or cleaning a tube is much cheaper than replacing compressor or the entire refrigerator. Do not wait until the products begin to deteriorate.
Prevention and proper maintenance
What To reduce the risk of problems associated with noise and hissing, it is necessary to regularly service the equipment. Cleaning the drainage hole is a simple procedure that you can do yourself using a brush or a special wire. This will prevent stagnation of water and subsequent hissing as it evaporates.
It is also important to monitor the position of the refrigerator. It must be level, without distortions, so that the oil circulates correctly in the compressor and the refrigerant does not create plugs. Regular defrosting (for models without No Frost) will prevent the formation of excessive ice crust, which can also be a source of strange sounds when melting.
Check the door seals. If they do not fit tightly, warm, humid air enters the chamber, which increases the load on the system and the amount of condensation. Wipe the seals and check their elasticity at least once every six months.
Why does the refrigerator hiss after defrosting?
After defrosting, a lot of moisture remains in the system. When the compressor is turned on for the first time and the defrost system begins to operate, this water actively evaporates, falling on the hot elements. This is normal and will go away after a few hours of operation.
Is hissing dangerous for food?
Hissing itself is not dangerous for food. However, if it is caused by a freon leak or a compressor failure, the temperature in the chambers will begin to rise, which will lead to damage to the contents. Monitor the temperature.
Can a new refrigerator hiss?
Yes, new refrigerators can make more varied sounds during the “break-in” period. Expansion and contraction of plastic, valve adjustment and initial oil circulation can cause sounds that will disappear after 1-2 weeks of operation.
What to do if the hissing is accompanied by an odor?
If you smell burning or plastic along with the hissing, immediately unplug the refrigerator. This is a sign of overheating of the wiring or insulation. You need to call a technician to diagnose the electrical part.
Does the load level affect the sounds?
Indirectly, yes. An overloaded refrigerator has poorer air flow, which can disrupt the defrost cycle and lead to the formation of ice, which will subsequently hiss as it melts. An empty refrigerator operates in shorter cycles, which also changes the acoustics.