The appearance of extraneous sounds in a household refrigerator always causes concern among owners, especially if the equipment previously operated silently. The characteristic crackling sound can be either a normal variant associated with the physical properties of materials, or a signal of serious malfunctions condensing unit. Understanding the nature of the sound is the first step to solving the problem, allowing you to avoid costly repairs or wasted calls to the technician.
The intensity and frequency of the crackling noise depend on many factors: the age of the equipment, the type of refrigerant, installation conditions and the current load on the system. In some cases, it is enough to simply change the position of the housing, in others, you will need to replace thermostat or the starting relay. It is important not to ignore sudden changes in the acoustic profile of the device, since a timely reaction extends the service life of the equipment.
In this article we will analyze in detail the mechanical, electrical and thermal causes of crackling. You will learn to distinguish safe sounds from critical signals of a breakdown, which will help you make the right decision about further actions. A sharp metallic crackling sound when starting the motor most often indicates wear of the trigger mechanism or problems with the windings.
Natural causes of crackling: thermal expansion and refrigerant
The most common and safest cause of sounds is the process of thermal expansion of materials. The internal chamber of the refrigerator, made of plastic or metal, is constantly exposed to temperature changes. During sudden cooling or, conversely, during defrosting, the walls contract or expand, producing characteristic clicks. These sounds are absolutely normal for working equipment and do not require intervention.
The second natural source of noise is the movement of refrigerant through the piping system. Liquid freon, flowing from the condenser to the evaporator or vice versa, can gurgle, hiss or crackle. This is especially noticeable in models with a No Frostsystem, where the circulation of gases occurs more actively. If the sound resembles the pouring of water or a quiet hissing, there is no need to worry.
However, you should be wary if the nature of the sound changes to a loud, intermittent hum or knocking. This may indicate that air pockets have formed in the system or that oil circulation has been disrupted. In such cases, the cooling efficiency drops and the load on the motor increases.
- 🔊 Quiet clicks of plastic when first turned on or after defrosting are the norm.
- 🌡️ The sounds of metal expansion are more often heard in older models with enamel chambers.
- 💧 Gurgling freon usually subsides 10-15 minutes after the compressor stops.
Why does a new refrigerator crackle louder than the old one?
New models often use thinner insulation walls and modern refrigerants (for example, R600a), which circulate under a different pressure, creating louder sounds compared to R134a freon in older ones devices.
Problems with the compressor and start relay
If the crackling noise is heard precisely in the lower part of the refrigerator where the motor is located, the problem most likely lies in the electrical part or mechanics of the compressor. Often the culprit is starting relay the device responsible for starting the engine. When the contacts wear out or the plastic case breaks, the relay makes a loud click, after which the motor may not start or stop immediately.
The compressor itself can also become a source of noise when the service life is exhausted. Worn bearings, loose fittings or deformed internal valves lead to metallic clanging and crackling noises during operation. If the motor hums heavily and makes intermittent sounds, this is a sign of a serious malfunction that requires replacement of the unit.
⚠️ Attention: If you hear a loud crackling sound and see that the compressor is trying to start, but immediately stalls, immediately unplug the device. Repeated starting attempts can lead to burning of the motor windings.
It is better to diagnose the electrical part using a multimeter, checking the resistance of the windings and the integrity of the relay contacts. For an untrained user, visual inspection can be dangerous due to high voltage.
Fan malfunctions in No Frost systems
In refrigerators with an automatic defrosting system, the fan is responsible for circulating cold air. Over time, ice may accumulate on the blades, which, when rotating, begins to touch the housing or protective grille. This causes a rhythmic crackling or humming noise that intensifies when the door is opened (since in many models the fan stops when opened).
Another reason is wear on the fan shaft plain bearings. If the lubricant has dried out, the shaft begins to turn with difficulty, producing dry creaks and crackling sounds. In some cases, the blades may become deformed due to the age of the plastic or mechanical stress due to inaccurate defrosting.
To eliminate the problem, it is often necessary to completely defrost the refrigerator within 24 hours. If after this the sound returns after a few days, it means that the tightness of the seals is broken or the heating element of the evaporator is faulty, and ice builds up again.
- 🌀 A rhythmic crackling sound, depending on the operation of the motor, often indicates the fan.
- ❄️ Ice growth on the blades is a sign of problems with defrosting evaporator.
- 🔧 Replacing a fan usually costs less than repairing a compressor.
The influence of improper installation and vibration
Often the source of the crackling sound is not inside the unit, but outside. If the refrigerator is not level, vibration from the operating compressor is transmitted to the cabinet, floor or nearby furniture. This causes rattling of glass shelves, bottles or decorative elements, which can easily be mistaken for equipment failure.
Check the distance between the back wall of the refrigerator and the wall of the room. If it is too small, vibration can be transmitted to the building structure, creating a resonating hum. It is also important to make sure that the refrigerator does not touch adjacent cabinets or walls.
Particular attention should be paid to adjusting the support legs. An unstable position of the housing leads to misalignment, which is why the doors may not fit tightly and the internal mechanisms may work under increased load. Use a building level for fine adjustments.
| Surface type | Probability of resonance | Recommended solution |
|---|---|---|
| Linoleum/Tile | High | Use anti-vibration pads |
| Wooden floor | Medium | Align the legs, check the joists |
| Carpeting | Low | Make sure the legs are stable |
| Uneven floor | Critical | Urgently level the supports |
Defects in the evaporator and capillary tube
The evaporator itself can be the source of the crackling sound, especially in the freezer. As temperature cycles, the aluminum evaporator plates expand and contract. If the fastenings are loose or the geometry of the block is broken, the plates may rub against each other or against the housing, producing loud sounds.
The capillary tube through which the refrigerant moves is also subject to vibration. If it is not secured properly or touches metal parts of the case, a characteristic metallic ringing occurs. In systems with Low Frost or static cooling this is less common, but possible.
It is important to distinguish these sounds from the noise of freon boiling. Mechanical friction usually has a higher frequency and resembles the ringing of metal on metal, while gas movement has a softer sound. To eliminate mechanical contact, it may be necessary to carefully bend the tubes or install dampers.
⚠️ Attention: Bending the evaporator tubes or capillary system yourself is dangerous! Thin aluminum easily bursts, which will lead to freon leakage and expensive repairs with sealing of the system.
Diagnostics and methods for eliminating noise
To accurately determine the source of the sound, it is necessary to carry out consistent diagnostics. Start by visually inspecting and listening to the unit running. Try to localize the area where the cracking is coming from: top, bottom, back wall or inner chamber.
Try to lightly press on the walls of the refrigerator or change the position of the case. If the sound changes or disappears, the problem is vibration or fasteners. If the cracking persists regardless of external influence, the internal unit is probably faulty.
☑️ Primary diagnostic checklist
If simple methods did not help, a more in-depth check of the electrical components will be required. However, if you do not have the skills to work with electrical appliances, it is better to entrust this task to a professional.
When you need to call a specialist
There are a number of signs in which self-repair is not only ineffective, but also dangerous. If the cracking sound is accompanied by a lack of cold, a burning smell, or frequent blackouts, you should not hesitate. These are symptoms of serious problems with the compressor or electrical wiring.
A specialist’s help is also needed if the start relay, thermostat or fan in complex models needs to be replaced. The technician has the necessary tools and spare parts, which guarantees high-quality repairs.
Do not forget that opening components (for example, a sealed system) automatically voids the warranty. Therefore, for new equipment, any suspicious sound is a reason to contact an authorized service center.
- 🛑 The smell of burnt wiring or plastic - turn off the device immediately.
- 📉 Lack of cooling when the engine is running is a sign of a freon leak.
- ⚡ Frequent power surges or knocking out plugs is an electrical problem.
⚠️ Attention: Prices for compressor repairs can reach 70% of the cost of a new refrigerator. If the appliance is old, sometimes it is more profitable to buy a new model than to repair the old one.
Why does the refrigerator only crack at night?
At night, the overall noise level in the room decreases, and the sounds of operating equipment become more noticeable. In addition, at night the voltage in the network may be more stable, which affects the operation of the motor, or the doors open less often, changing the thermal regime.
Is it possible to lubricate the fan yourself?
Theoretically, it is possible if you have access to the bearing. However, in most modern models the fans are not serviceable and require complete replacement. Using the wrong lubricant (for example, WD-40) can only worsen the situation by dissolving the remaining factory lubricant.
Is cracking noise dangerous for the food inside?
The sound itself does not affect the food. However, if the cracking sound is caused by a problem with the cooling system (such as a fan or compressor stopping), the temperature in the chamber may begin to rise, causing food spoilage. Control the temperature.
How long can a refrigerator operate with a bang?
If the crack is caused by thermal expansion - indefinitely (infinitely). If it is wear of a relay or fan - from several weeks to several months. If the compressor is cracking, it can fail at any time, from an hour to a year.
Does the type of refrigerant affect the noise?
Yes, refrigerators using isobutane (R600a) often operate quieter, but require more precise tuning of the system. Freon R134a can create more noticeable sounds of liquid flow due to different physical properties and pressure in the circuit.