Split AC Is Making Noise

The first time you heard that horrible sound, you were justifiably unnerved. You searched all over your house trying to figure out what the source could have been. You’ve since unplugged the fridge, the oven, and the living room TV, but none of those appliances and electronics seem to be responsible for the noise, as it persists.

Ruling out your options is good, as now you can say with more confidence that it may be an HVAC unit, even your split AC. The problem is your air conditioner can make all sorts of noises depending on the issue. Let’s take a closer look at the sounds you might hear from your split AC.


This noise is almost like a bubbling. During some moments, the sound is pretty distinct, but in other cases, it almost blends into the background. Even still, if your split AC gurgles, it’s because the unit has collected too much moisture. The blockage pipe may have a hole or a backup that’s led to it malfunctioning.


No, that’s not your cat hissing at you, or your dog either. It’s your split AC. This sound signifies a leak in one of the air ducts, usually in the room in which you most loudly hear the hissing. Using the wrong type of air filter with your split AC can also make the unit hiss, and so can a bad expansion valve.


When your split AC first kicks on, a bit of clicking is perfectly normal. It’s when the sound persists that you know something isn’t right. The thermostat has probably gone haywire, so you’ll need a new one sooner than later.


Why your split AC rattles can come down to a few reasons. We’d advise you to check outside first, as the outdoor compressor may be covered in leaves or dirt that are prohibiting it from working correctly. Barring that, then the electrical contractor within the split AC is on its way out.


That annoying buzzing sound is caused by the compressor’s fan blades. The blades might have come loose so they’re making contact with the interior of the compressor. Other parts may be undone in the compressor and are buzzing. The split AC’s copper lines could be blocked, the condenser coils need cleaning, or the outdoor fan motor is broken.


A humming sound is almost too easy to miss since it doesn’t start very loud. Still, this noise is your contactor relay switch crying out for mercy. Your split AC might not work if the relay switch fails, so don’t delay in getting those repairs done!


Oh goodness, what is that awful shrieking sound? You guessed it, it’s your split AC. The fan motor, besides making the unit buzz, can also lead to ear-piercing screeches. The compressor’s motor might also be producing an audible death knell.


This one is scary because it almost sounds like someone’s knocking on your door. A banging air conditioner has a damaged compressor. This allows the other parts around the compressor to come apart, so now you’ll have banging and rattling at the same time.