After installing an air conditioning or heating unit, it’s common to hear some noises coming from the system. Many of these sounds are part of normal operation, but others can indicate a serious issue. Use this guide provided by Custom Aire to see if you should call a professional when your HVAC system is making a strange noise.

Air Conditioning Noises

Most air conditioners now contain sound-dampening features that help reduce the amount of noise they make, but you may still hear something that could mean it’s time for a repair. Here’s a breakdown of some common noises that an air conditioner may make and what they mean:

  • Humming: This usually occurs in functioning air conditioning systems, but if humming is louder than normal, it could mean a loose part. It probably isn’t serious, but should be examined.
  • Banging or clanking: These are a step up from humming and can indicate that a part is much looser or off-balance. When the noise reaches this stage, it’s time to call a professional.
  • Clicking: You may hear this when turning your air conditioner on or off, but if it persists, then it could indicate that the thermostat is failing or a control is defective.
  • Squealing: This can let you know that either the blower motor or fan motor has a problem.
  • Chattering or rattling: These noises are serious and mean that there is something clogging the system or that the system is starting to deteriorate and you may need a replacement.
  • Screaming: This is the most problematic sound your air conditioner can make. It indicates either a refrigerant leak or high internal pressure that could lead to an explosion. Shut the unit down as soon as you hear this and call a professional.

Duct Noises

The ducts in your walls are made up of several connected parts that allow the flow of air. Many duct sounds are simply a part of normal functioning, but there are some situations in which noisy air vents can indicate a serious problem. Some noises that you may hear from your ducts are:

  • Popping or banging: These sounds shouldn’t be worrisome, as they indicate the duct walls expanding or contracting because of a change in temperature.
  • Booming: This is also caused by temperature changes, but happens when there is a spot without dampers or expansion joints, so the sound is louder. Still, this noise shouldn’t be an issue.
  • Rattling: If your system is old, the sealant holding parts in place can loosen and pipes can start knocking against one another. This can mean it’s time for a replacement.
  • Buzzing or scratching: This can occur when small animals, like bees or mice, have found their way into the ducts. It’s important to work with an animal removal specialist or exterminator to eliminate these pests before they cause damage.

Furnace Sounds

Like your air conditioner and duct systems, pay attention to the sounds your furnace makes as well. Common sounds from a furnace include:

  • Knocking: This can mean sounds from the blower are allowed to move through the furnace because the vibration damper isn’t installed correctly. This won’t affect its performance, but can be fixed to reduce the noise.
  • Huffing or puffing: These sounds can occur when a burner or gas valve is corroded or faulty, which requires a repair.
  • Squealing: When a belt is frayed or the blower is dirty, you may hear this high-pitched sound. If left unattended, it could develop into a more serious problem.
  • Grinding or scraping: These are the more concerning noises related to the blower. They can indicate a failing blower motor that needs repair or replacement.

Get the Repairs You Need

Hearing noises coming from your HVAC system can be worrisome, but not all of these sounds need immediate attention. When you hear a problematic noise, contact Custom Aire to find out the right steps to take. Our experienced team can assist you with air conditioning, heating and vent cleaning for both commercial and residential spaces to get your HVAC equipment in working order.