Aircon Noisy – Causes, Signs & Troubleshooting Tips

Do you find your air conditioner is making noisy sounds? Whether it is a squealing, buzzing, screeching or rattling noise, it can be annoying and distracting. In this blog post, we will explore the most common causes of noisy air conditioners and provide some troubleshooting tips on how to fix them. Read on for more information to solve your problem and keep your AC running quietly again!

What Are The Causes Of A Noisy Air Conditioner?

Common causes of a noisy air conditioner include blocked airflow, dirty air filters, loose fan blades, faulty fan belts, and dirty fan blower blades.

Blocked Air Flow

Blocked air flow can be one of the major causes of a noisy air conditioner. Obstructed airflow can occur when filters are clogged, or window treatments, furniture and other objects block vents. A blocked airflow will cause inadequate performance from the unit and an increase in noise levels as it works harder to try and circulate air around your home.

A simple visual inspection of these components may reveal any blockages, which you can remove to restore adequate airflow throughout your system. Regularly clean or change your filters to prevent them from becoming clogged with dust and other particles that can reduce efficiency and lead to noisy operation.

Dirty Air Filter

The air filter of an air conditioner can get clogged up with debris, dust and pet hair over time. This impedes the normal airflow causing the fan to become noisy, as it has to work harder to pull air through. Regularly replacing or cleaning an air filter is an easy fix for a noisy AC unit.

If your filter is over two months old, change it to a new one. When checking the filter, look out for any tears or rips in the fabric, which can also lead to restricted airflow and excess noise from your air conditioner. With proper maintenance, you can avoid having noisy AC units caused by dirty filters in your home or office.

Loose Fan Blades

Loose fan blades are a common cause of noisy air conditioners. When the fan blades become unprepared, they can start making loud noises when the AC runs. This noise occurs because the unbalanced blades wobble and vibrate as they spin around their central hub. The vibrations cause rattling, humming or buzzing noises from within the unit.

The loose fan blade must be re-secured with screws or another method prescribed by your model’s manufacturer before any other noise diagnosis and repair begin. If left unchecked, this issue could result in further damage to surrounding components such as cracked plastic covers, broken circuit boards, etc., resulting in more costly repairs down the line for an already burdensome expense.

Faulty Fan Belts

Faulty fan belts are another common cause of loud noises from an air conditioner. Fan belt failure can result in the inability of the system to move air through the ducts and out of the vents, which causes noise as the unit struggles to keep up with demand. Faulty fan belts must be replaced by a qualified technician immediately for optimal operation and reduced noise levels.

Worn or loose fan belts can also produce squeaking, squealing or rattling noises when they come into contact with other parts in the AC unit due to their lack of tension. In this case, tightening or replacing these worn belts should return your air conditioner to its normal, quiet state.

Dirty Fan Blower Blades

cause a noisy air conditioner, resulting in a screeching or rattling sound. Dirt and debris can build up on the fan blades over time and reduce their efficiency; this leads to loud noises as the air conditioner struggles to push air through. To fix this problem, it is important to inspect and clean out the blower fan blades regularly.

To clean out the blower fan blades, you must ensure they are free from dirt or debris by vacuuming them off with an appropriate vacuum cleaner attachment. If necessary, you can also use compressed air or a soft-bristled brush to remove hardened dust particles from the blade’s surface. Finally, lubricate all the moving parts within your air conditioning unit for optimal performance.

Loose Mounting Screws

One of the main causes of a noisy air conditioner is loose mounting screws. Loose mounting screws can cause a rattling or vibrating noises as the unit struggles to operate correctly. Therefore, it’s important to inspect all mounting screws from time to time and ensure they are properly secured.

If your air conditioner has been making more noise lately than usual, checking for loose screws should be one of your first troubleshooting steps. In addition to visually inspecting them, you can also use a screwdriver or other appropriate tool to check if any screw holes have become stripped due to wear and tear.

Refrigerant Leaks

Refrigerant leaks can be very serious as they may cause your air conditioner to become noisy and inefficient. Leaking refrigerants are caused by corrosion from long-term use or a faulty component such as a valve, O-ring, or gasket. Refrigerant leakage should be checked immediately to prevent further damage and noise emission from the unit.

If you suspect that there is refrigerant leaking in your system, then hiring an experienced HVAC technician is essential for repairs and maintenance of the affected component/s. The service person will check for visible signs of leakage through visual inspection or scan with the device, along with pressure testing on various components to detect any leaks in the system.

What Are The Common Types Of Air Conditioner Noises?

The common types of noises an air conditioner makes include squealing, buzzing, high-pitched screeching, rattling and clattering.

Squealing Noise

Squealing noises are usually caused by a worn fan belt or improperly aligned pulleys in the air conditioner. Worn fan belts can become brittle and have difficulty transmitting power to the fans, resulting in squealing noises. Also, loose or misaligned pulleys supporting the blower wheel can cause vibrations that create loud squealing sounds. Proper maintenance and regular servicing can identify these problems early on before the issue worsens.

A grinding noise may sometimes sound similar to a squealing noise from your air conditioner; this is usually caused by debris such as pebbles, leaves, dirt and dust that clog up your unit’s motor bearings and prevent them from running smoothly. If you notice strange noises coming from your AC system accompanied by grinding sounds, it’s time to call an HVAC specialist for further inspection.

Buzzing Noise

Buzzing noises are common noises emitted by air conditioners, which can indicate an issue with the fan. The buzzing could be due to an obstruction in the fan blades, or a loose blade or screw inside the unit may cause it. If left unserviced, this can lead to extensive damage and a costly repair bill.

To ensure that any buzzing noise is addressed as quickly as possible, regularly inspect the fan for signs of rust, wear and tear or obstructions. Additionally, check that all mounting screws are securely fastened and clean out any dust from within the blower housing to prevent future issues with your air conditioning system.

High-pitched Screeching Noise

High-pitched screeching noises indicate a problem with the motor, bearings or fan components. This is usually caused by wear and tear on the parts due to age, excessive use, lack of maintenance or extreme temperature fluctuations.

If neglected for too long, this type of noise can cause major damage to your air conditioner’s compressor and other vital components, which may lead to expensive repair bills.

Rattling Noise

Rattling noises are often caused by loose fan blades, screws, or parts that have come undone. Inspecting these components and fastening them tightly to prevent further noise and disruption is important. Faulty bearings within the motor can also cause rattles; in this case, it is best to replace the entire motor as soon as possible before further problems occur.

Rattling noises can also mean a lack of lubrication inside the air conditioner’s system. The moving parts should regularly be lubricated and checked for damage or cracking to ensure they function properly without much noise disturbance. If there is not enough lubricant within an AC unit’s moving parts, then it could cause a rattling sound when running, which will require more oiling and maintenance check-ups for optimal performance.

Clattering Noise

Clattering noise is usually caused by loose parts inside the air conditioner unit. This can be due to a worn fan blade, a broken blower wheel, or general wear and tear over time. It is also possible that debris has built up in some areas of the unit, increasing the rattling sound as components rub against each other. Inspecting your system regularly for signs of damage or wear and identifying potential causes before attempting any repairs is important.

To fix this problem, it is necessary to check all internal components thoroughly and ensure they are securely fastened, as loose parts may cause further damage if ignored. Additionally, regular cleaning of the condenser coils can help reduce clattering noises due to accumulated dust and grime trapped between them. Lastly, it’s important to replace any worn-out parts, such as fan blades or belts, before clatterings become too loud for comfort.

Troubleshooting Tips To Fix A Noisy Air Conditioner

Locate the noise source and take action by following effective troubleshooting tips such as checking the air filter, looking for loose fan blades, inspecting the fan belt for wear and tear, etc.

Check The Air Filter

The first step to fixing a noisy air conditioner is to check the air filter. An unclean or clogged filter can block airflow, causing your AC unit’s fan blades and blower motor to overwork and make more noise than usual. Ensure your air filter is regularly checked and changed every 3 months for optimal results.

It’s important to note that dirty filters reduce the cooling system’s efficiency, resulting in higher energy bills. This makes it all the more necessary to monitor your air-conditioning systems’ cleanliness frequently for better performance and quieter operation.

Look For Loose Fan Blades

Loose fan blades can be a common cause of air conditioner noise. Start by inspecting the fan blades for any signs of damage or loosening, and if found to be the culprit behind your air conditioner’s problem, make sure to tighten it right away. Regularly check its condition and replace them if worn out or damaged. This should help reduce the noise coming from your AC unit considerably.

Another thing you should also look out for is debris caught between the fan blade edges, as this could affect its spinning motion and create vibrations that result in loud noises when running. Cleaning your AC’s fan blades regularly will prevent such issues, keeping it quiet and efficient.

Inspect The Fan Belt For Wear And Tear

A fan belt, or a drive belt or v-belt, is used to power the air conditioner’s mechanical components like the compressor and blower motor. To fix any air conditioner problems that may arise from a faulty fan belt, it is important first to inspect the fan belt for wear and tear.

Look out for cracks in the fan belt’s surface material and signs of fraying. This can indicate that the fan belt needs to be replaced.

Additionally, listen out for squealing noises when running your unit; this could mean too much tension on your belts, requiring adjustment or replacement.

Check For Refrigerant Leaks

Refrigerant is an essential component of a functioning AC system. Leaks in refrigerant can lead to the compressor not running and result in a noisy operation. If your air conditioner is making unusual noises, it could be due to low refrigerant levels, which must be identified and repaired immediately.

It’s important to have your AC system checked annually by a professional for any signs of leaks or low refrigerant levels, as this can help prevent issues later on down the line. A technician will inspect all other components, such as hoses and connections, ensuring everything works correctly.

If you suspect refrigerant leakage, call in an experienced HVAC specialist immediately who can troubleshoot and identify any underlying problems with your AC unit, including detecting potential leaks through specialised testing methods. Replacing or refilling the lost coolants should end unruly noises coming from your air conditioner and restore its optimal performance.

Check For Loose Mounting Screws

When troubleshooting a noisy air conditioner, it is important to check for loose mounting screws. These screws help secure the cabinet to the wall or floor and can become loose over time due to vibrations from normal usage.

If these are not tightened properly on installation, they will loosen eventually and cause rattling noises inside the unit. To fix this issue, use a screwdriver or power drill to tighten all of the screws securely.

Regularly check the mounting screws during maintenance checks as part of general upkeep.

Clean The Fan Blower Blades

The fan blower blades are one of the most important components of an air conditioner unit. They help to circulate cool air throughout the house and must be kept clean for optimal efficiency. To clean them, turn off the power supply to the unit and use a vacuum cleaner with a soft brush attachment to remove dust from all surfaces. Use a soft cloth lightly dampened with warm water if there is any build-up on the blades.

It is also important to regularly inspect these fan blades for any signs of wear or damage which could affect their performance. Replace any worn parts immediately as they can cause further damage if left unchecked. Ensure all mounting screws and wiring harnesses are secure before powering up again after cleaning the fan blower blades!

Clean And Service The Fan

The fan is an important component of the air conditioning system and needs to be regularly cleaned and serviced. This involves removing dust and debris from the blades, lubricating parts if needed, and checking for loose components. If the fan is not properly maintained, it can become noisy, affecting your air conditioner’s efficiency.

It’s also important to inspect tubing leading away from the fan blower unit for signs of bending or crushing, as this can restrict airflow, causing your AC unit to run louder than normal. Lastly, ensure all connections are tight so no external vibrations can affect its performance. Regular servicing will help keep your Fan running safely and efficiently while reducing noise levels significantly.

Remove Dust And Debris

Removing dust and debris from an air conditioner is necessary for its upkeep. Dirty components can lead to increased noise, decreased efficiency and even system failure.

To clean the unit effectively, you should use a vacuum cleaner with a soft brush attachment to extract dirt from any visible areas and within the fan assembly. Check for any accumulations of dust or lint around vents on both the indoor and outdoor units.

Finally, ensure all crevices are clear, and no debris remains inside the filter housing or in other interior components.

Lubricate And Inspect Parts

Lubricating the moving parts of your air conditioner can help reduce any noise coming from them. Regularly inspect each part for wear and tear, as this could be causing excess vibrations and resulting in a loud noise.

Ensure all parts are securely connected and tightened to limit their movement within the unit. You may need to call an HVAC technician if you’re not familiar with the system or its components to properly lubricate and inspect any specific parts that may require more attention.

Inspect Tubing And Ensure It Is Secured And Properly Connected

It is important to inspect the air conditioner’s tubing and ensure that it is properly secured. Check for any kinks, splits, or punctures in the tubing as these can cause a decrease in efficiency and performance. Also, check that connects are firmly tightened so there are no leaks in the system.

The refrigerant lines also need to be inspected regularly and ensure they fit correctly with no gaps between them. If any of the connections look old, worn out or damaged then replace them immediately with new parts from a reliable source. Additionally, ensure all of clamps used to secure the lines stay tight when vibration occurs during normal operation.

Tips To Avoid Noisy Air Conditioners

By following simple preventive maintenance tips, you can ensure that your air conditioner runs quietly and efficiently for years to come. Read on to learn more about how to prevent noise and other problems!

Regularly Change The Air Filter

To keep a noisy air conditioner at bay, it is important to regularly change the air filter. Filters should be changed every three months as they can become clogged with dust and debris which reduces cooling efficiency and may even cause increased noise levels.

This will also improve indoor air quality by trapping airborne particles like pollen, pet dander and other allergens from circulating around your home.

Schedule Annual Maintenance Visits

Scheduling an annual maintenance visit with a licensed HVAC technician is one of the best ways to prevent noisy air conditioners. During a regular service, they can inspect the parts and components of your unit to look for any potential problems that could be causing noise as well as suggest solutions or repairs if necessary.

Additionally, during a service call, you may want your technician to lubricate certain parts such as fan motors and blower blades which helps keep them running smoothly and lowers the chance of rattling noises occurring when in use. Finally, it’s important to have your unit checked annually for signs of refrigerant leaks which can cause loud compressor operation and reduce efficiency levels significantly.

Check For Any Signs Of Damaged Or Worn Parts

It is important to check your air conditioner regularly for any signs of damage or wear. Look out for any cracks, leaks, loose parts, abrasions or bent parts and replace them promptly. Make sure all the screws are tightly secured and functioning properly to avoid rattling noises from vibration and other abnormal conditions. If you suspect a part may be compromised, it’s best to get it checked by a qualified technician as soon as possible.

Your fan belt should also be checked periodically for signs of wear and tear such as cracking and fraying. A worn or damaged fan belt can cause noise due to lack of tension on the pulleys so make sure it is replaced at once if needed. Other components like mounting screws should also be inspected for tightness since these could lead to vibration noises if they become loose over time. Proper lubrication will help reduce friction and thus extend the life span of your air conditioner’s moving components.

Keep The Condenser And Evaporator Coils Clean

Keeping your air conditioner’s condenser and evaporator coils clean is an important part of routine air conditioning maintenance. Debris build-up on the coils can reduce airflow, affect operation and create loud noises when turned on.

To ensure coils remain in good condition, it’s best to have them wiped down regularly with a damp cloth or brush. Doing so will help protect your unit from operating inefficiently as well as reduce future repair costs.

Additionally, doing this cleaning task instead of hiring professionals would save you some money in the long run.

Clean Or Change The Air Filter Regularly

Cleaning or changing the air filter is important to air conditioner maintenance. A dirty air filter can block the flow of cold air, causing the air conditioner to have to work harder and cause it to become noisy.

To keep your AC running efficiently and without noise, regularly check and replace your unit’s filter at least once a month during peak usage periods. The more often you change your filters, the quieter your AC will remain.

Have Your Unit Checked Annually

Annual air conditioner maintenance is highly recommended to ensure it runs efficiently and effectively. It’s important to have an HVAC technician inspect, service and clean the system every 12 months to detect any existing problems or potential parts needing replacement. Having a professional check on your unit can reduce the chances of developing serious issues like excessive noise.

The technician should always start with an overall inspection before moving on to more intricate tasks like lubricating or checking components for wear and tear. Additionally, they can make necessary adjustments if anything is not running optimally as well as check its performance levels against industry standards so that you get positive results from the maintenance visits. Lastly, regular servicing helps improve air quality by removing dust particles from all internal components so that nothing obstructs airflow within the unit.

Insulate Any Exposed Ductwork

Insulating any exposed ductwork is one way of reducing noise from your air conditioner. This will help reduce the transmission of sound waves and provide an extra layer of sound dampening. Doing this yourself can be relatively easy and only requires insulation, tape, screws, and other tools.

For more effective results, consider using fibreglass-based insulation materials as these have superior noise reduction capabilities due to their higher-density nature. Professional installation may also be a better alternative for larger area coverage or difficult-to-reach places in the ductwork system. Whichever route you take, proper installation is key to maximising sound-dampening benefits from insulating any exposed ductwork.

Check The Evaporator Coil Every 3-5 Years

The evaporator coil is an important air conditioning system component and should be checked every 3-5 years. During a regular service check, a technician will inspect the evaporator coil for any signs of wear or damage and blockages caused by dust and debris.

If not properly maintained, an inefficient evaporator coil can cause noise from your air conditioner due to loud vibrations of the fan blades or malfunctioning fan motor. As part of preventive maintenance, serviced coils should also be lubricated periodically to reduce noise levels when running.

Regularly checking on the condition of your evaporator coil will ensure that it operates at peak performance and helps extend its lifespan while preventing noises associated with faulty components like worn-out bearings or loose screws.

Utilise Regular Servicing

Regular servicing of your air conditioner is an essential part of its upkeep. By scheduling regular visits from a certified technician, you can keep your unit in top working order and reduce noisy operation.

Having the system assessed and serviced every 6-12 months will ensure that loose screws are tightened, fan blades inspected and lubricated, parts checked, and any signs of wear or rust addressed accordingly. Regular servicing also enables technicians to identify developing issues before they become major problems which could be costly to repair or replace.

Monitor Unit Operation Regularly

It is important to keep a close watch on your unit’s operation. Check for any signs of unusual noises, temperature fluctuations or performance issues. If you notice anything that doesn’t seem normal, it could indicate an underlying problem. To ensure the smooth and efficient running of your air conditioner, monitor its operation regularly.

It is also important to check that all thermostat sensors are working properly. In addition, always consider the age of your air conditioner and assess whether it is time for regular servicing or even replacement if necessary. Regular maintenance will help reduce any long-term breakdowns due to wear and tear and improve efficiency, saving money in the long run.

Finally, talking with an HVAC professional can provide expert advice on how best to maintain and operate your system correctly without experiencing unnecessary noisiness or other problems in the future.


Noisy air conditioners can be a nuisance, especially if you’re trying to get some rest or focus on something in your home. Luckily, there are several measures you can take to fix the problem.

Checking for common causes, such as blocked airflow, loose fan blades, faulty belts, and dirty filters, can help identify the noise source. Furthermore, cleaning and servicing the unit regularly will ensure it continues running smoothly while avoiding potential issues like excessive vibration or rattling noises. Regular maintenance and inspection visits allow you to keep your air conditioner running silently!

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