Troubleshoot A/C Noises Before Scheduling HVAC Service

A/C noises

Here’s a potentially scary story: it’s a hot day in the Orlando area and the heat index is flirting with 100 degrees. You escape indoors to avoid melting onto the sidewalk, and suddenly the air conditioner makes a not-so-good noise. Yikes! Fortunately, you can troubleshoot A/C noises if this ever happens to you. Here’s a quick guide:

  • Loud banging noises may mean that the A/C motor is failing or that a rotating shaft has come unbalanced on its bearings. It could also mean that something is hitting the fan, which could be a serious problem.
  • Are you hearing a loud clunk, or a sound like shoes knocking around in the dryer, when the system shuts off? Have someone check the blower fan assembly, which could be loose.
  • A constant hum and intermittent buzz from the outdoor compressor unit could be that the compressor motor has seized or the contactor relay or start-run capacitors are bad.
  • Clicking and ticking noises coming from your system, especially just after it shuts off, could mean a fan is wobbling and hitting something. It could also mean loose hardware or a malfunctioning relay.
  • If you’re hearing a loud hissing from the A/C, watch out! Just like in the animal kingdom, it could indicate danger. In an air conditioner, it might indicate dangerous over-pressure conditions in the unit.
  • Popcorn noises? This could indicate a problem in the refrigerant line. Refrigerant passes from a gas stage to a liquid stage and back again as it passes through various parts of the system. When it stays in liquid form, it can lead to refrigerant flooding and make noises like these. An HVAC professional should take a look at this immediately.

While being able to troubleshoot A/C noises can give you a bit of insight into your unit, it’s always useful to get a professional opinion. If you have any concerns about your A/C this summer, call Scott’s Heating & Air Conditioning!

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