20 May. 19

Why Your Air Conditioner Is Making A Clicking Noise?

It is quite natural for air conditioners to make a variety of sounds after a long time of usage. These sounds constitute a normal part of the operation of your system and should not be alarming. However, some sounds from your system prove a possible problem with the air conditioning as it inhibits the cooling process. A sound that is natural for an AC is the sound of airflow. There are several other sounds which prove that your air conditioner is malfunctioning including clicking noises from it.


You need to know the type of sounds your AC is making to understand the origin of the problem. Note that authentic air conditioners contain sound-damping and two-stage compressors that maintain below 55 decibels noise-level. Do not ignore unusual sounds from your air conditioner because it could mean it needs the service of a repairer. Sometimes, all your AC needs is a routine service, but you wouldn’t know this.


Here, you can learn how to detect the type of sound your air con is making and understand the various possible solutions. If the mysterious noises of your AC are ignored, minor problems can cause significant expenses. The reason is that these noises can ultimately go from a simple tuning to costly repairs or replacing the machine.

A common example of an abnormal AC noise is a persistent clicking noise which can develop over time inside the air conditioner. To avoid unnecessary expenses, you must be quick to provide a solution to these sounds. The earlier the cause of the noise can be determined, the faster you can get to resolving the problem.


But before that, you should get familiar with the types of sounds your air conditioner can exhibit. Therefore, let’s briefly discuss them.

Types of air conditioner sounds

Before you can detect the probable source of any AC noise, you should be able to differentiate the sounds. Furthermore, if you can know where the particular sound coming from your air conditioner is, it will help you assist the repairer. By informing them of the exact noise, you have saved them a visit which saves time for both parties. Below is a list of HVAC sounds, their causes, and DIY solutions:

1. Banging

This noise can mean several things, but it is nothing to be greatly concerned about. It typically means there is a loose or broken part of the air conditioning compressor. The possible options are:

  • A broken connecting rod
  • A loose piston pin
  • A loose crankshaft
  • An unbalanced indoor blower

Worst case scenario, you would need to replace the compressor of the air conditioner, and that is all.

  • As a solution:
    Firstly, put off your air conditioner. Remember, this advice is entirely optional, and you don’t have to do it yourself. Secondly, examine the compressor system; check for any loose constituents. If there is any, replace it. Ensure that the replacement is standard for your air conditioner before buying it.


2. Clanking

It is merely another sound that indicates that there is a loose or unbalanced component in the air conditioner. It is most likely that some parts of the closed unit are malfunctioning, which means the compressor has become loose. Therefore, your compressor needs a replacement as soon as possible.

Furthermore, it could even be that the fans of the indoor blower are out of proportion. If the fans are out of place, they can hit other components, which leads to the clanking sound you hear. Leaving this noise unattended can cause worse challenges, so you should call in an HVAC expert quickly.

3. Clicking

When you start or stop your air conditioner, it’s reasonable to hear clicking noises coming from it. However, constant clicking noises coming from your air conditioner is something to worry about. This persistent noise can mean a defective control or a malfunctioning thermostat.


Your air conditioning system comprises of several vital electrical parts, and each should be in good condition. It is essential that you keep a close watch on minimal electrical challenges, like excessive clanking, before it gets worse.

If the clicking noise only occurs during the start-up and shutdown of your AC, then don’t do anything. Nevertheless, if the noise is ongoing after start-up, then check your thermostat because you may have to replace it. Even better, contact a reputable HVAC technician for your air conditioner repair.


4. Buzzing

Unlike the clicking noises, the buzzing noise you hear is coming from outside your air conditioner. Ultimately, the buzzing noise means various air conditioning challenges. This noise may indicate any of the following:

  • Loose or unbalanced fan blades
  • Defective or out of balance blower
  • A disorderly condenser coil
  • An air filter that needs to be replaced
  • Intertwined copper lines
  • Presence of debris in the indoor, outdoor, or both.
  • Leakage in the refrigerant which results in the freezing of the air conditioning
  • Loose components  

To improve your air conditioning and stop the buzzing noise, it is advisable to clear debris. But the best thing to do is to turn off your air conditioner immediately and get a technician to repair it.

5. Squealing

In some cases, this sound is utterly standard during the start-up of the air conditioner. Outside of regular start-ups, this kind of noise comes from the duct system like most blower and fan noises. The affected components that cause loud squealing noises are the outdoor fan and indoor blower motors. Also, other parts, like the blower wheel and housing, are liable to squeal if they malfunction.

  • To solve the noise:
    Firstly, you must identify if it is a sound that the unit makes typically or if it indicates a faulty system. If the noise only occurs during start-ups, then you should not be bothered. Nevertheless, if this sound is a new development, then you should consider changing the outdoor fan motor or indoor blower motor.

6. Humming

Generally, when you hear this sound coming from your air conditioner, it is usually normal, unlike clicking noises. However, the humming noise could also serve as an indication that something is off in the AC. The possible sources of the noise are loose components and refrigerant piping. The two units cause vibration, but if you don’t handle the sound quickly, it can lead to more complications.

In other cases, humming noises may be triggered by loose wiring, which can mean electrical problems. It can also be a motor-related issue, especially if the compressor hums and doesn’t start. A simple solution is to check for loose components in the internal parts of your condenser unit. For better results, you should call a local tested and trusted HVAC technician.

7. Rattling

Unfortunately, a rattling noise indicates that the state of your air conditioner has begun to decline. Also, the deterioration naturally comes with loosening parts. The other possibility is that leaves or twigs have gathered in the system and are obstructing it from functioning correctly. Failure to quickly attend to this noise can lead to significant repercussions, including a damaged compressor.

A lose fan also rattles; therefore, this is another potential source of the noise. The first thing to do when you hear rattling is to examine your air-con for loose screws or bolts. Afterward, you should tidy up the condenser coils and replace the indoor air filter. If the noise persists, then you can call an HVAC company to fix it.

8. Screaming

This noise is an aggravating sound, and you should shut off the air conditioner instantaneously. The recommendable thing to do immediately you hear whistling or screaming is to call for professional help. The main reason for this noise is a refrigerant leak which can be harmful to humans. A refrigerant leak not only damages your air conditioner but also threatens the health of your family.

Furthermore, screaming can also imply a hazardous internal pressure in the compressor. Some air conditioners will turn off to protect you, so don’t panic if that happens. In fact, take it as a good sign. It means a sensor works to safeguard you against potential danger.

Finally, it is generally a good idea to turn off your central air conditioner as a preventive measure. Put it off when you hear an unusual persisting sound and wait till it is thoroughly inspected by a professional. Also, an annual checkup and servicing as a means of maintenance work can be a preventive plan against potential defects. It is costly to repair or change any component of your air conditioning system, so adapt to the preventive measures.

The causes of clicking sound in an air conditioning system

There are common challenges that may cause the clicking noises that may be produced by your air conditioner, so you need to know them. By understanding each possible challenge, you will be able to gauge the level of damage. Here are some common issues you should know:

Compressor Hardware Problems

One of the main components of your air conditioning system is your compressor. Clicking or ticking noises coming from your air conditioner can cause problems with your compressor. It is advisable to contact a reputable HVAC company immediately, to avoid needing a new air conditioner.  Any noise coming from outside or inside can indicate an imminent collapse of the cooling system. This is the type of technical problem that must be addressed urgently.

If the clicking noise is an external one, it can also result in a compressor problem. Nonetheless, this is not ultimately alarming. It could merely be loose bolts or one that hasn’t been removed first, as with shipping hardware. Also, loose screws can produce a soft click, as it hits the AC frame because of the vibration of the running unit.

Clicking noises may range from minor nuisances to worse intrusions, but you should contact a technician nonetheless. A competent technician will examine the AC and get to work immediately. Repairs done on an AC unit carry the risks of both electric shock and excessive component damage. Therefore, a licensed AC expert is best left to do this.

Capacitor / Control Board Defects

If your system turns itself on, say every 20 seconds, it can indicate:

  • A defective control board
  • A malfunctioning fan engine
  • A faulty condenser, or switch.

Any delay or attempts to solve your problem yourself may result in a bigger problem for your air conditioner. What many homeowners are ignorant about is that every time your aircon starts or stops, it makes an audible click. However, it is normally just one click whereby the thermostat sends a signal to the condensers to ignite.

It may be an electrical problem if the clicking noises from your air conditioner become constant as a result of a continuous startup of the system. The thermostat sends the signal, but they can not be implemented, due to the shortness of the wires. Sometimes, it may be the switch on the condenser or control panel. In any case, an air conditioner service technician is needed before it gets worse and you have to repair or replace it.

Fan Blockage

The first and most accessible area to control is the inside air filter fan unit. A clicking noise that slowly starts and goes as your unit warms up can be caused by a blockage of the fan. Other times, it may just be a curved fan blade. Note that every time the blade hits the debris, the click will happen. The noise will continue until the removal of either the obstruction or the blade.

Unsecured Fan

A loose fan or a faulty relay switch may lead to clicking noises when your unit is on or off.  Often, if a fan gets loose, the case is that it is worn out or something has hit the condenser. Maintenance usually prevents the wearing of fans in the air conditioning system.  

Malfunctioning Thermostat

Another probable cause of clicking noises is a faulty thermostat. After a long time, your thermostat will wear out, while your air conditioning system might still work. This partial function of the AC will result in a struggle to perform. The struggle can be loudly heard through the clicking noises coming from your air conditioner.

Fortunately, it is easy to source for what is making your air conditioning system malfunction. Clicking noises range from slow at startup to fast and continues even after the AC is shut down. However, the frequency of these sounds can help you to troubleshoot the problem.

It is vital to inform the technician about the oscillation of your air conditioner before repair. Clicking noises from your air conditioner are best solved before they get worse. Our HVAC experts can help you handle these noises. Get in touch with us today!

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