April 6, 2021
Central Air Conditioning in Shawnee, Kansas

When the weather gets warm, it’s easy to go to the thermostat and simply switch on the air conditioner. The system turns on almost silently, and everything starts to cool down again.

But what happens when it isn’t that easy and your system starts to make noise? There are noises you should be aware of that indicate your system needs service.


A humming can be a sign of several problems. On the simple end, it can be caused by something loose in your system. On the more serious end, it could indicate a problem with your compressor motor failing to start. One common cause of this kind of humming accompanied by your system not starting is a faulty capacitor. Even if your problem is not serious right now, if it is not resolved, it can become serious very quickly.

Clanking or Banging

Banging and clanking sounds will likely draw your attention very quickly because they are loud and repetitive. These can indicate several other types of problems. Easily fixed are problems with a component like your circulating or compressor fans being out of balance. It could also signify a serious problem with your compressor.


Squealing is never a good sound from your air conditioning system. You will likely be able to hear this very well because the sounds are transmitted through your duct system. A squealing sound usually originates from a fan motor going bad. Your system likely has two: one outside for the compressor fan and one inside for the circulating fan.

In some cases, you may hear a little squealing as the system starts up. If you are unsure if your squealing is normal, call to have it inspected. If the blower motor is going bad, it will raise your operating costs. It will also add strain to your system, causing it to age prematurely.


Most people will never know the sound of their air conditioner screaming, so if you do, take notice. The most likely cause of this is a refrigerant leak. This will not only damage your system, but it will pose a health hazard. If you hear a screaming sound, shut down your system and call for repairs. If you can, open some windows to increase air circulation just to be safe.

Helicopter Whirring

Your system should operate nearly silently, so if it sounds like the whirring of a helicopter, you may have a problem. From a mechanical perspective, this kind of sound usually comes from a bearing going bad in one of the fan motors. However, it could also be as simple as something like a piece of paper having gotten trapped in the system. The point is, investigate to find the cause in order to rule out mechanical problems.


Rattling or chattering can be a general sign your system is starting to age. Normal systems will last 10-15 years when properly maintained. If your system is starting to age, you can expect several things to start wearing out. The fan blades may be getting loose, or you may have loose mounting bolts or screws. The condensing unit contactor may also be getting old, which will cause a chattering sound. Left unresolved, this can put excessive wear on your compressor by making it constantly start and stop.

Rattling can also be caused by something simple like twigs caught in the compressor fan cage. Be sure to check your outside unit frequently to keep debris out of the way.


Buzzing is another fun sound that could mean many things. These could include:

  • Debris caught in the system
  • Condensing fan motor about to fail
  • Loose fan blades
  • Other loose parts
  • A refrigerant leak
  • The system needs to be cleaned


When your system first starts up, you may hear a number of different clicking sounds. This could be from your thermostat as well as from several relays within the system starting different parts on time.

However, you should not hear constant or ongoing clicking as your system runs. If you do, you likely have an electrical component about to fail. Once you notice the unusual clicking, get your system serviced to keep from causing more damage.

Air conditioners are like most mechanical devices. If you leave small problems unchecked, they will turn into much larger, more expensive problems. Air Care Heating & Cooling has provided Shawnee residents with trusted air conditioner repair services for over 25 years. We also provide installation and maintenance options, along with a full range of heating and indoor air quality services. Call to schedule your air conditioning repair call today.

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