Why Is My Air Conditioner Making Noise?

1 Aug
Air Conditioner Noises

Why Is My Air Conditioner Making Noise?

You think you’ve heard that noise before but never quite that loud, and is it really exactly the same in the first place? HVAC systems are rugged and meant to see you happily through the muggiest summer days. What happens, though, when your tried-and-true unit begins to complain? This wouldn’t mean trouble, would it?

Learning to Speak HVAC

When your air conditioner moans and groans, it really needs you to listen. Each of those different noises it makes has a particular meaning. If you’re more familiar with ancient Greek than you are with the sounds you’re hearing, the following translation will help you understand.

It’s time to consider calling in the troops when your air conditioner begins to:

  • Scream. When your outside unit emits a high-pitched sound or hiss for 10 to 15 seconds after turning on, it’s likely due to a buildup of pressure in the compressor. When this is the case, the unit itself may cycle on and off excessively. This situation can be quite dangerous, so it’s best to shut the air conditioner off entirely and call an HVAC repairman to come and have a look.
  • Screech. If your outside unit emits a sound resembling metal against metal, the chances are that the fan’s motor bearings have given up the ghost. If so, the entire fan motor is due for a replacement. You can keep running the unit if you absolutely must, but make plans to have this fixed as soon as you can.
  • Squeal. This sound will almost always indicate a problem with the belt. Replacing it will solve the problem, and if you notice signs of wear, it’s best to do this before the belt breaks entirely. Once it does, the blower will cease to turn.
  • Clank, rattle, thump or bang. The air conditioner making this type of racket usually has a problem with its motor or blower assembly. This sound will usually occur when a particular component has begun to loosen. If the rattle turns into a bang, some part has likely disconnected or broken entirely. At this point, you’ll have no choice but to shut off the system and have a qualified HVAC repairman check the motor mounts and bearings or see if the blower has fallen out of alignment.
  • Gurgle. If your air conditioner starts to gurgle as it runs, one of two things is probably wrong. It is either having an issue with its condensate drain line or else it has sprung a refrigerant leak. Although the drain line situation is not too serious, the leak will require professional help.
  • Thwack or slap. This sound closely resembles that of a playing card clipped to and hitting the spokes of a turning bicycle wheel. It normally indicates the presence of a foreign object stuck in the blades or something in the housing that is contacting the blower, and removing the intruder should resolve the problem.
  • Click. Any working HVAC unit will make a clicking sound when it turns on or off, but when the noise repeats in the area of the outside compressor or control panel, it might indicate a defective relay or a bug in an electrical control.
  • Rattle. Loose panels on the condenser or evaporator housing are the commonest cause of a rattling sound. In this case, tightening the screws that hold it in place will often solve the problem. Other causes of this particular noise include a misaligned fan, a broken motor or debris blowing around inside the cabinet.
  • Whistle. When seals along your air conditioner’s seams and cracks fail to do their job, escaping air will generally result in peculiar whistling noises. Loose screws or bolts around these areas are often to blame, and the same is true of caulking faults or failure of tape to adhere to the duct seams.

An air conditioning unit in good working order will not make any of these sounds. When yours begins emitting anything more troubling than white noise, it’s time to call in the pros. The HVAC repair specialists at Windy City Air take pride in diagnosing and correcting the most annoying and exceptional air conditioning problems. Don’t wait until the temperatures rise routinely to triple digits. Take these noises for the warnings they are and call Windy City Air today at 702-932-7284.

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