Talking About Air Filtration Systems

Talking About Air Filtration Systems

Air Conditioner Whisperer: Interpreting The Noises Your A/C Unit Is Making

Tammy Terry

Maybe the problem just started or maybe it's been going on for awhile, but your air conditioner is making odd noises that have you concerned. Although these appliances aren't able to talk (yet), it's still possible to interpret the clanks and bangs your unit is making to diagnose the cause. Here are a few different sounds air conditioners make when something is wrong and their potential sources.

Rattling Noises

The most common reason for rattling noises is debris. It's not unusual for small items such as leaves, sticks, and pebbles to fall into the cabinet of an air conditioner. You can confirm this by removing the cover and looking inside. A/C units are built to prevent this from happening, so it's essential that you investigate how the debris got inside the machine and patch the problem after removing the items.

Loose panels and misaligned fans are other things that can cause rattling noises. This is usually caused either by screws working themselves loose or debris knocking around and damaging components. If you don't see any debris when you remove the cover, check the screws on the fan and panels, and tighten them if they're loose.

The third thing that can cause rattling noises is a broken motor (alternatively, it may make a grinding sound). This piece of equipment has quite a few moving parts since it's responsible for controlling the condenser and fan. Over time, the parts wear down and elements begin breaking off or shifting, causing a rattling sound. Since it can cost anywhere from $400 to $500 to replace a motor, have a professional diagnose this is the problem before investing the cash.

Hissing or Whistling Sounds

This sound can be caused by two things. If you hear the noise inside your home whenever the air conditioner turns on, the problem most likely will be your ductwork. The hissing may indicate that you have holes in the ducts that are letting air escape. Patching the holes will typically eliminate this issue.

On the other hand, if the hissing noise is coming from the air conditioner itself, then the problem may be a refrigerant leak. These leaks can occur in a number of ways including accidental damage to lines connecting the refrigerant to other components, cracks in the evaporator or condenser coils, and manufacturer defects. If the air passing through your register is lukewarm or weak, there's ice on the evaporator coils, and/or refrigerant is being blown to exterior parts of the machine, then you probably have a leak.

Refrigerant leaks must be fixed by a professional. Failure to address the issue can result in at least a 20 percent increase in your energy bills and a reduction in the lifespan of your air conditioner.

Screeching or Squealing

This noise typically indicates the belt on the motor may need to be lubricated or replaced. This is generally a problem with older air conditioning units, as newer ones don't use belts to power the blower. As time passes, the belt weakens, slips from its original position, or stretches out. If it appears this is the issue with your belt, then it needs to be replaced.

If the belt doesn't look damaged or is new, it may need to be lubricated. Be certain to use oil that's specially designed for this application. Common lubricant products used for household tasks are usually too light to be effective.

When your air conditioning units starts making strange sounds, it's a good idea to have it checked out by an HVAC technician who can accurately diagnose the problem, saving you time and money. To schedule an appointment to have your unit checked, contact an HVAC company in your area. For more information, check out websites like  


2019© Talking About Air Filtration Systems
About Me
Talking About Air Filtration Systems

Hey everyone, I am Mort Nicholas. Since I have allergies to pollen, dust and chemicals, I must filter the air blowing through my home day and night. The air filtration systems hook straight to the furnace and air conditioner to provide my home with fresh air at all times. The filters used for these systems capture the tiniest of particles to keep them out of my airways. As a result, I often wake up feeling healthy and refreshed. I hope to share the benefits of having filtered air flowing through your home. I will discuss symptoms caused by contaminated air. In addition, I will share information about air filtration maintenance services provided by HVAC contractors.