Come On, Feel the Noise: Why Is My AC So Loud?

What’s that racket? If you’ve turned down the music, but you’re still hearing banging, grinding, or hissing noises, it’s time to turn your attention to a different type of heavy metal — your air conditioner. Let’s look at some common noises that might be coming from your unit, which ones can be easily fixed, and which require a visit from your HVAC specialist ASAP.

Bring the Noise

Noisy AC units are among the most common complaints we get. It’s important to understand that even a properly functioning air conditioner is still a large, metal machine made up of lots of moving parts that are working hard (especially during those Central Texas summers) to keep your home cool. It’s not always quiet work. If you’re bothered by your unit’s everyday noise, ask your HVAC technician about noise-reduction solutions.

Prick Up Your Ears

If the noise is a new development, it’s important to identify what it is and where it’s coming from. Here are a few of the most common culprits:

  • Rattling: If your outdoor unit is rattling, it’s possible something has fallen into the vents. Check your unit for debris like leaves and sticks. Also check that all screws, bolts, and fasteners are tightened — loose connectors could also be the source of the noise.
  • Banging/Clanking: This is a sign that something inside the compressor is loose, broken, or unbalanced. You’ll want to call in your HVAC specialist to take a look — a compressor replacement might be in order.
  • Grinding: Grinding noises usually mean that something is wrong with one of your fan motors. Possibly, the bearings are worn down. It’s important to get this looked at soon, as the failing part could cause damage to other parts of your unit.
  • Buzzing: This can be the result of a number of different issues. There may be debris in the unit or the condenser coils might need to be cleaned. The fan blades might be loose or out of balance. The fan motor or blower might be about to fail. If you hear a buzzing noise and your unit keeps freezing up or isn’t cooling, you might have a refrigerant leak. Contact your HVAC specialist immediately.
  • Clicking: Most units click as they cycle on and off. However, constant or continuous clicking could indicate a defective thermostat or control.
  • Popping: This usually indicates an issue with your ductwork, not your AC unit. Just like the rest of your system, ductwork is subject to wear and tear and requires regular maintenance.
  • Hissing: If the hissing noise is coming from inside the house, it’s another indication that ductwork repairs might be in order. If, however, the hissing is coming from the outdoor unit, it might indicate a refrigerant leak. This is a major issue and needs immediate professional attention.
  • Screaming: This is the most serious one. If your unit is making a high-pitched screaming noise, shut it down and call your HVAC specialist immediately. There might be unusually high internal pressure in the compressor, which can be very dangerous. Your unit might shut down on its own, which is a good thing — an internal sensor is protecting you from the potential hazard.

No Noise Is Good Noise

It’s important to know what your unit sounds like on any given day, so that you recognize when an unfamiliar noise is trying to alert you that something’s off. While some issues can be fixed with a simple cleaning, many require professional help and the replacement of worn down parts. Don’t ignore strange noises! At worst, they signal truly dangerous situations that can lead to the need of a new AC unit. More often, ignoring them will lead to more costly repairs down the line. Contact your HVAC professional, so you can enjoy some peace and quiet!