Appearance An extraneous hum, whistle or crackling sound in the operation of refrigeration equipment is often the first signal about the need for maintenance. Owners of household appliances are often faced with a situation where the cooling system works properly, but fan makes irritating sounds that disturb the peace in the apartment. The main reason for this behavior is most often drying out or contamination of the lubricant in the sliding bearings of the electric motor.
However, before taking active steps, it is necessary to clearly understand which materials are permissible to use. The wrong choice lubricant can lead to node failure in a matter of days or even hours. In this article, we will analyze in detail the chemical and physical properties of various oils so that you can make an informed decision on restoring the performance of your No Frost or combined system.
Diagnostics of problems with the refrigerator fan
Before looking for an answer to The question is how to lubricate the fan in the refrigerator, you should make sure that the problem lies precisely in the bearings. Users often confuse bushing wear with blade imbalance or foreign objects. The first sign of lubricant depletion is an increasing hum, which intensifies as the load on the motor increases. If you hear periodic squeaking or cracking noises, this indicates dry friction metal surfaces.
For an accurate diagnosis, you need to gain access to the evaporator by removing the back panel in the freezer. Visual inspection allows you to identify shaft play. Rock the blades with your finger: if you feel a noticeable movement to the sides or the shaft rotates with uneven force (sometimes easy, sometimes hard), it means the bushings are worn out or lack lubrication. It is important to note that modern models, such as Indesit or Atlantoften use sleeve bearings, which are critical to the quality of the lubricant.
There is also the possibility that the noise is caused by freezing. If ice has formed on the blades or around the shaft, the fan will operate under overload. In this case, lubricant will not help - defrosting is required. But if the mechanism is clean and dry, and the sound remains, then it's time for service. Ignoring this stage can lead to jamming of the shaft and burning of the motor windings.
Strictly prohibited substances for lubrication
The most common mistake that inexperienced craftsmen make is the use of improvised means that are not intended for working in low temperatures. Classic machine oil or waste oil is absolutely not suitable. At temperatures of -18°C and below, prevailing in the freezer, the viscosity of such liquids increases sharply. They turn into a thick mass, which not only stops lubricating, but permanently blocks the rotation of the shaft.
⚠️ Attention: Never use edible oils (sunflower, olive, butter). Organic fats tend to oxidize and polymerize in air, turning into a sticky resin. After a week, such a “repair” will require a complete replacement of the fan, since it will be impossible to clean the bushings from fossilized oil.
You should also avoid using solid oil, lithol and graphite lubricants in their pure form. These materials are too thick for high-speed plain bearings in household fans. Their use will cause the motor to overheat, trying to turn the thickened mass. Additionally, many aerosol lubricants, such as the classic WD-40, are solvent-based. They can wash away the remnants of old grease and temporarily remove noise, but after a couple of days the situation will worsen due to the effect of “dry operation.”
Particular attention should be paid to the compatibility of materials. Some synthetic oils can react chemically with the plastic of the fan housing or rubber dampers, causing them to deteriorate. Therefore, the choice should fall only on specialized compounds that guarantee stable properties over a wide temperature range. Using the wrong chemicals is a direct path to expensive repairs of the compressor group.
Why is WD-40 not a lubricant?
WD-40 is a Water Displacement agent. Its base is white spirit and low-viscosity mineral oils. It perfectly displaces moisture and deoxidizes rust, but quickly evaporates, leaving parts without protection.
Suitable types of oils for low temperatures
The ideal solution for servicing refrigeration equipment are synthetic oils designed specifically for extremely low temperatures. The leader in this category is synthetic oil for sewing machines. It has a low viscosity, does not thicken in the cold and does not evaporate when the motor windings heat up. It is these compositions that are often recommended by manufacturers of household appliances for servicing moving parts.
Another excellent option is silicone lubricants. They are inert to plastics and rubber, do not change their consistency when cooled to -50°C and have excellent water-repellent properties. Silicone creates a stable film that effectively reduces the coefficient of friction. On sale you can find both liquid silicone oils in bottles with a dispenser and sprays, but for spot application it is better to use liquid.
For more loaded components, where there is noticeable play, you can consider special frost-resistant lubricants for refrigeration equipment. They are often labeled H1 (food safety) or indicate an operating temperature range of up to -60°C. Such compositions are more expensive, but provide maximum service life. It is important that the selected oil is transparent and does not contain solid particles that could act as an abrasive.
Comparative table of lubricants
To systematize the information and simplify the choice, we will consider the main characteristics of various types of lubricants in a comparative table. This will help you understand why saving on a specialized product can lead to unnecessary costs.
| Lubricant type | Operating temperature | Effect on plastic | Recommendation |
|---|---|---|---|
| Oil for sewing machines | from -30°C to +150°C | Neutral | Optimal choice |
| Silicone oil | from -50°C to +200°C | Safe | Excellent option |
| Motor oil (mineral) | from -15°C to +100°C | May be corrosive | Not recommended |
| Edible vegetable oil | thickens at -5°C | Oxidizes | It is strictly forbidden |
As can be seen from the table, specialized synthetic fluids win in all respects. Their ability to maintain fluidity at sub-zero temperatures is a key factor. The use of motor oils is permissible only as a last resort and only if they are synthetic and have the appropriate index, but the risk of damage to the plastic elements of the bushing remains high.
Step-by-step instructions for lubrication of the fan
The process of servicing the fan requires accuracy and adherence to the sequence of actions. The first step should always be to unplug the refrigerator. Unplug the cord from the outlet and let the unit stand for at least 15-20 minutes to discharge the capacitors and stabilize the pressure in the system. Only after this can you begin disassembly.
Next you need to dismantle the back panel in the freezer. It is usually attached with self-tapping screws or plastic latches. Be careful with plastic at low temperatures - it becomes brittle and can crack if handled carelessly. After removing the panel you will have access to the evaporator and fan. In some models, for example Bosch or LG, the fan can be hidden by an additional casing.
☑️ Preparation for lubrication
The lubrication process itself depends on the design of the bearing. If it is an open bushing, place 1-2 drops of oil directly onto the shaft at the entrance to the motor housing. If the structure is closed, you often have to remove the fan itself, remove the retaining ring and carefully remove the impeller along with the shaft. Old dried grease must be removed with a cotton swab dipped in alcohol or Galosh gasoline. After cleaning and drying, apply fresh oil.
⚠️ Attention: Do not overfill with oil! Excess lubricant can get onto the motor windings or temperature sensors, causing them to malfunction or catch fire when turned on. Two or three drops are enough for quality maintenance.Assembling and checking the results
After applying the lubricant, reassemble the assembly in the reverse order. Make sure all fasteners are tight but not overtightened. Pay special attention to the fit of the impeller: it should fit tightly and not touch the housing walls or evaporator elements. The backlash of the blades should be minimal, exclusively within factory tolerances.
Turn on the refrigerator and listen to the fan operation. In the first seconds there may be a slight noise associated with the distribution of oil, but this should quickly disappear. If the hum disappears and the fan runs smoothly, then the procedure was successful. If the sound persists, perhaps the problem is not in the lubrication, but in the wear of the bushings or the balance of the motor itself.
Assemble the chamber, return the products into place and close the door. Check the temperature for several hours. Proper fan maintenance ensures efficient circulation of cool air, which reduces the load on the compressor and saves energy. Regularly checking the condition of the components extends the life of the entire refrigeration unit.
How often should the fan be lubricated?
In modern models with the No Frost system, maintenance is rarely required, once every 3-5 years, or when noise occurs. In older models, the interval can be 1-2 years.
Frequently asked questions (FAQ)
Is it possible to lubricate the fan without removing it completely?
Yes, if the design allows access to the shaft. Often it is enough to remove the impeller and drop oil onto the axle, turning it by hand to distribute the lubricant. However, complete cleaning of old dirt is only possible with complete dismantling.
How many drops of oil are needed for one lubricant?
Usually 2-3 drops are enough. Sliding bearings in refrigerators have a small working chamber volume. Excess oil will create additional resistance and may leak out.
Why does the fan make noise immediately after defrosting?
This may be due to residual moisture or ice trapped in the bearing. It is also possible that the old lubricant has lost its properties due to freeze-thaw cycles, and now needs to be replaced.
Will graphite lubricant replace special oil?
No. Graphite grease is too thick and contains solid particles. It is not suitable for high-speed bushings of household fans and can accelerate wear or jam the shaft in the cold.