Because most new central air conditioners built within the last decade are designed to operate very quietly, with variable speed motors and fan blades designed to reduce noise, when you do hear unusual noises, or the unit is runs much louder than usual, it is often a sign of a problem. It may be a symptom of a part has worn out and is about to fail. By being aware of these noises you can address the small problems before they lead to an expensive breakdown.
A central air conditioner is going to make some sounds when it is working normally. Subtle thumping, hissing and whining sounds are normal. By becoming familiar with the normal operating sounds that an air conditioner makes, you will be able to more easily recognize unusual sounds that could be a cause for concern.
The Sounds of a Malfunctioning Air Conditioner
Air conditioners have many parts; there are fans, hoses, belts, compressor motors, coils and other components that work together to move cool air throughout your home. As air conditioners age belts often loosen, leading to thumping sounds
. A clogged air filter will reduce air flow and can cause the unit to whine
as it cycles on and off. Loose hardware on compressor parts can lead to rattling sounds
One of the most common causes of a central AC unit running more loudly is a lack of maintenance. Annual maintenance is important to address the small problems like worn out belts, loose mounts, and other problems before they result in a major breakdown. Preventative maintenance is the best way to minimize the likelihood of air conditioner repairs. An AC tune-up includes the following steps that keep your air conditioner operating quietly and reliably. Annual AC maintenance includes some common items like:
- Inspection and lubrication of moving parts
- Inspection and replacement of worn belts and hoses
- Replacement of dirty air filters
- Ensuring that the unit cycles on and off properly
- Inspection of electrical connections
- Inspection of refrigerant levels
AC Rattling Noises
Rattling noises are a pretty common with air conditioners. Over time the various fasteners attaching components to the unit can come loose. If you hear rattling, check the screws or bolts holding the cover plates in place. If the rattling noises persist after tightening the panels, remove the cover and check internally for the same issue. After listening for rattles, always turn the power to the unit off at the breaker.
AC Whistling Sounds
Whistling sounds are usually heard when seals are leaking. Check for cracks and gaps in the seams of ducts near the unit and the duct work that carries the air throughout the home. Examine the seams around these areas for loose connections and re-tighten any screws or bolts. If heat tape was used to also cover the seals, make sure the tape completely adheres to the duct seams.
AC Screeching Sounds
Like your car, the air conditioner motor uses belts. If there is periodic screeching that only occurs when the unit turns on to blow air or cool the air down, it is likely a worn-out belt that needs to be replaced. Over time belts can stretch and wear out. A qualified HVAC technician should check the belt and replace it if needed.
Clunking sounds can mean something has come loose inside the air conditioner unit. A loose fan blade on a motor can make sounds as it turns. Or it could be a plastic component or cover plate coming into contact with the.
If you're hearing unusual sounds from your central air conditioner, call Air Specialties Heating and Air Conditioning. We will inspect the unit to ensure it is operating safely and reliably.