Learn What Those Unusual Noises From Your Air Conditioner Unit Mean

Posted on: 30 December 2014

Conventional residential air conditioners do not run silently. A typical unit emits small occasional clicks and a continuous whirring sound. However, unusual noises from the AC unit usually point to a specific problems. Here are a few examples of common air conditioner noises that usually mean something is wrong with the unit:

Clicking or Sudden Loud Rustle

A clicking sound, or a loud rustle that develops suddenly, is not good news. In most cases, your condenser will make this sound if there is debris trapped inside the unit. The noise is due to the debris hitting the fan blades. Common debris that that may find its way into your AC's exterior are small tree twigs (the grate only blocks larger pieces).

If you hear such noises, turn off the AC immediately and remove the offending object, if you can see it. Call a technician if you can't remove the debris, or if there is visible damage to the fan or any other part of the unit.

Loud Hiss

A loud hissing noise usually points to an escaping rush of fluid. Therefore, it may mean that the refrigerant or air is leaking. If you know how the normal rush of air sounds in your vents, you will know when it changes to an audible hiss. In that case, you may be dealing with a damaged coolant line or a compromised ductwork. The solution? Call an air conditioner technician to offer a remedy.

Banging, Thumping or Rattling

Any of these sounds may mean that there is a mechanical fault in your air conditioner. This is especially the case if the sounds remind you of metal hitting metal, which points to the presence of a loose piece of metal in your AC unit. It may mean that something is loose, such as a screw or belt. Replacing or tightening the loose part usually solves such problems.

Squeal or Thump With Each On-And-Off Cycle

Another sound you may hear from your air conditioner is that of a regular squeal or thump. These sounds are usually made by old units during the start and stop parts of their cycles. Aging (and loose) belts and dirty rotors are usually part of the problem. A simple tune-up service usually resolves such issues.

In general, you shouldn't ignore any unusual noises from your air conditioner. This is especially true of loud noises that start suddenly. If you don't know that a sound signifies, call an AC contractor from a company like Patriot Heating & AC LLC to help you figure it out and fix the problem.