Turning Down the Volume on an AC Unit Making Loud Noises

Your AC is supposed to run quietly enough that you barely even notice it, especially since you’ll be running it frequently in the Houston-area heat. If you’re stuck with an obnoxious rumble, rattle, or buzz instead, you could have a deeper issue that needs attention.

Before you call for air conditioner repair, here’s what might be causing that loud sound in your AC.

Why Is My Air Conditioner So Loud?

The reason for your deafening AC could be several things. You can narrow down the cause of your loud air conditioner based on what’s making noise and when.

My Outside AC Unit Is Making a Loud Noise

Your outside unit, exposed to the elements as it is, is the most likely to be damaged through general wear and tear. If you hear buzzing, check that your unit is debris-free, especially if there’s been a storm lately.

Similar things can happen to internal units, including parts wearing out, coming loose, and failing. If you hear a hissing noise from your outdoor unit, turn it off immediately and schedule emergency repairs. This is most likely due to leaking refrigerant, which can potentially be very dangerous.

Why Is My Air Conditioner So Loud Inside?

The most common cause of loud noises inside your AC unit is loose parts. If something has come loose in your unit, it can rattle around, potentially causing further damage as it creates a racket.

A noticeable but not deafening whistling or whooshing noise may come from your indoor air conditioner due to an obstruction in the vents or a dirty filter. Change your filter and see if the problem resolves. If it doesn’t, you could benefit from duct inspection and cleaning to clear out anything clogging up the inside of your vents.

My Air Conditioner Makes a Loud Noise When Starting

Many air conditioners click when they turn on and off, but the noise should seem normal. If your AC makes a loud noise as it turns on, it could be coming from your compressor, indicating that the part is starting to go bad.

Do you mostly hear banging as your unit starts up, and occasionally throughout the heating and cooling cycle? Your blower wheel could be loose and banging against other machinery parts. You should call a technician to handle inspecting and replacing any broken or out-of-place parts.

If the noise is more constant and sounds like creaking metal, you could be hearing your sheet metal ducts expanding and contracting. You might hear this as the air comes on, but it’s more likely to happen after the AC has been running for a few minutes. This sound is normal and doesn’t require a fix, but if it’s disruptive, you can have a pro inspect your ducts and offer solutions.

My Air Conditioner Makes a Loud Noise When Turning Off

If your system has dampers to control the flow of air from your air conditioner to different parts of your home, they may slam shut when your system turns off. You can adjust your damper’s actuator settings until the banging stops or upgrade to spring-loaded dampers that don’t bang. If the problem persists, call a professional to have a look.

What Noise Is Your Loud AC Unit Making?

• Buzzing. An inside or outside air conditioner making a loud buzzing noise can mean a range of things, including debris stuck in the outside unit, rattling copper lines, loose internal parts, or a malfunctioning compressor. If the sounds don’t go away after a basic clean-up of your unit, call a professional.
• Humming. Your air conditioner’s loud humming sound probably isn’t your AC at all. It’s likely a problem with your electrical system or a voltage concern. This will require a professional electrician to resolve the issue.
• Rattling or banging. One or more parts of your air conditioner may have come loose and could be rattling around inside the metal shell. Call a technician to identify the part and reattach or replace it as necessary.
• Squeaking or squealing. In your outdoor unit, this often means a motor is going out and will need to be replaced. Inside, the most likely culprit is a failing blower fan. Get either replaced by a technician.
• Whistling. If you hear high-pitched and loud whistling or screeching, especially from your outdoor unit, shut off your AC immediately and call for emergency service. You likely have a refrigerant leak or pressure build-up somewhere in your system, which is dangerous.

Get Professional Service for Your Houston-Area Loud Air Conditioner

Heading into summertime in Houston requires a fully functioning AC system. Ditch the earplugs and call in the professionals at One Hour Air Conditioning & Heating of Houston to keep your system running all summer long. We’ll diagnose the source of your sound and provide the repairs or replacements you need, most likely in a single visit. Call us at (713) 352-7903 or book an appointment online.