Why Is My AC Unit Making a Loud Noise?
July 02, 2024

July can be a noisy month. It has loud firecrackers, backyard party music, excitable children, and even late-night fireworks. But summer noises aren't just restricted to the outdoors—sometimes we hear them inside, too! If you've ever wondered why your air conditioning unit is making a loud noise, you've come to the right place.
Have you ever told your AC system to calm down because it's being too loud? (Apologies to Taylor Swift.) If so, you're not alone. Many homeowners notice their AC unit making loud noises on occasion. But it's knowing what these noises mean and how to handle them that matters most.
Here are some helpful tips if you've ever wondered, "How do I stop my AC from making a loud noise?"
Common AC Noises and Their Causes
If your AC is making a rattling noise...
Debris in your outdoor unit is the most common cause of a rattling sound. Inspect the unit and remove any sticks, debris, or rocks near the system. If you notice anything stuck around the unit, remove it and see if the rattling stops.
If your AC is making a banging noise...
Loud bangs can be very startling, but they can be especially worrisome if they come from inside your cooling system. A loud band often signals that something is wrong with the compressor. Sometimes, this results from a failing AC system. The banging means that something inside is loose or coming apart. Whatever the issue, the HVAC service pros at Blue Dot are always available for AC repair and new air conditioning installation!
If your AC is making a hissing noise...
Typically, a hissing sound indicates a refrigerant leak. The sound comes from air getting caught in the refrigerant lines. Give our team a call, and we will fix the issue!
If your AC is making a buzzing sound...
No, it's probably not a bee inside your system. Instead, a buzzing noise could indicate a dirty filter restricting air flow, some loose wiring, electrical trouble, a bad capacitor, or a failing compressor. To determine your diagnosis, call the Blue Dot Team for a service appointment.
If your AC is making a clicking sound...
It's normal for a thermostat to make a quiet clicking noise when it turns on and off. However, constant clicking is never a good thing. Repetitive clicking or ticking sounds could mean:
- Your thermostat is malfunctioning and causing the compressor to short cycle (turning on and off constantly and sounding like a click).
- Your fan blades may be misaligned, or you may have an electrical issue.
- The AC capacitor can't provide the necessary jolt of electricity to start the compressor or fan motor, so the system clicks and fails to start.
If your AC is making a squealing sound...
Does it sound like a mouse chasing a wheel inside your system? In most cases, high-pitched squealing noises indicate too much pressure inside the air compressor. High pressure inside your system is quite dangerous. So, if you hear squealing and suspect your pressure is too high, turn your AC off, and please call us ASAP.
Any DIY Tips?
Are there any do-it-yourself tips you can use when your air conditioning unit is making loud noises? Yes! Try these:
- First, turn off the power. Then, turn off the AC breaker on the electrical panel and the outdoor disconnect box.
- Clean debris from the outdoor unit—remove any twigs, leaves, dirt, or other debris. Also, gently shake the top grate. If you notice rattling, you likely have some loose screws. Tighten 'em up!
- Check the air filter. Dirty air filters can make your system work harder than usual and cause whistling sounds. If yours is dirty, replace it and see if the noise stops.
When to Call a Blue Dot Technician
Call the Blue Dot team anytime your AC unit is making a loud noise or when you find the air conditioning compressor making a loud noise. We are happy to evaluate your system and provide the quick solutions and repairs you need.
Blog Note: These sounds listed in this blog are possible indicators of what may be wrong with your AC system. To have your system professionally diagnosed, please call Blue Dot for service. Thank you!