Why Is My AC So Loud? Diagnosing Air Conditioner Sounds

Whats that noise?

When your air conditioning is quiet and humming along in good shape, it’s almost soundless. That can make AC unit clanks, hisses, squeals, and buzzes coming from your unit all the more alarming. What do these sounds mean? It’s important to find out fast — before they damage your HVAC system beyond repair. Remember, your friendly team at AC Designs is always here to help you with your HVAC service and maintenance.

AC Unit Making Loud Noise

For our experienced team at AC Designs, the different noises AC units make can give us clues to help diagnose specific issues. We recommend you film your air conditioning system whenever it makes noises, so we can better troubleshoot even if the air conditioner is quiet when we arrive to help.

In general, if your outside AC unit is making a loud noise, it’s likely in need of experienced HVAC repair. That’s because these loud noises can be caused by electrical issues like loose wiring or motor failure. It’s best to leave this type of AC service to professionals.

If you’re wondering why your air conditioner is so loud inside the house, first, check your air filter. If the air filter is clogged and dirty, your system will work harder to blow and be louder as a result. If everything looks clear, there may be a more serious problem that needs professional attention, like an unbalanced blower wheel.

AC Making Squealing or Screeching Noise

A high-pitched squealing or screeching noise from your unit is usually a sign of a belt or bearings issue. Narrowing this problem down usually involves assessing your AC’s age. In older AC units, the motor is connected to the blower fan with a belt. If this belt slips, it can make a loud, squealing noise much like a car or truck with a serpentine belt issue. Fortunately, replacing this belt can be a simple fix.

On the other hand, if your HVAC unit is relatively new, it doesn’t have this belt. Instead, the problem often lies in the condenser fan. A squealing or grinding noise coming from your outdoor air conditioning unit can be the first signal that the condenser fan’s motor needs replacement. Issues like this can be identified during your regular AC maintenance service.

AC Making Hissing Noise

Your air conditioning operates via a closed-loop system, which means that the refrigerant used to cool the air that’s circulated through your home can be reused over and over. But refrigerant can escape when this closed-loop system develops a leak, which makes it impossible for your unit to fully cool the air being cycled through.

Technicians use sophisticated leak-detection equipment to quickly find and repair leaks in your system. However, serious leaks can often allow refrigerant to escape quickly enough that you can hear a slight hissing sound from your indoor or outdoor unit. In these cases, you’ll usually notice that your AC isn’t cooling the air or is cycling on and off frequently.

AC Making Buzzing Noise

Buzzing sounds can come from several sources, making them more challenging to diagnose. Just a few of the potential causes of a buzzing AC unit include:

  • Loose parts rattling around somewhere inside the unit
  • Missing or broken isolation feet
  • A malfunctioning compressor
  • A refrigerant leak that has caused the unit to freeze

Figuring out precisely what’s wrong will require you to answer a few questions, like:

  • Does the unit buzz constantly, or only when it’s running?
  • Is the AC making a buzzing noise inside the house, or outside?
  • Is the AC adequately cooling your home?
  • Is there visible evidence of condensation on or around the unit?

Because the issues that can cause a buzzing AC unit don’t usually lend themselves well to DIY repairs, it’s a good idea to contact an AC service technician for diagnosis and repair.

Air Conditioner Makes Whooshing Noise

If your air conditioner is making a whooshing noise, it may be due to airflow issues or an obstructed air duct. When this happens, your AC might not cool your home evenly, and it could even cost you more on your energy bills. To fix it, you can check if your air filters are clogged, clear anything that’s blocking the air vents, and make sure the ducts are in good shape. 

AC Making Rattling Noise

An air conditioner rattling noise may indicate loose or damaged parts within the unit, which can disrupt your system’s performance and potentially shorten its lifespan. It’s essential to address this noise promptly by calling a professional for an inspection or repairs to prevent further damage and keep your AC running smoothly. 

How To Know When Your AC Unit Needs To Be Replaced

If you continue having problems with noises and temperature inconsistencies, it may be time for a new HVAC system. AC replacements are an investment, but can ultimately save you money down the line. A new unit that is properly maintained will require less frequent repairs and will be more energy efficient. Generally speaking, an AC unit approaching the 10-year mark is nearly due for replacement.

The Best Heating and Air Conditioning In Jacksonville, FL

AC Designs can help with any of your HVAC service or air conditioning maintenance needs. Whether your unit is screeching, buzzing, rattling, or just not performing up to par, our experienced HVAC technicians can quickly get to the bottom of any issues you’re facing. Give us a call or fill out the short contact form on our website to schedule your HVAC repair or maintenance today.