My HVAC is making a weird noise—should I be worried?
If your HVAC system has started making strange noises, you're not alone. We get this question all the time from homeowners across Greenville, Taylors, Greer, and the surround area.
The short answer? Sometimes yes. Sometimes no.
What Greenville Homeowners Should Know
But knowing which noises are normal and which ones could mean trouble can save you money and help you avoid a HVAC repair breakdown when you need your system most.
1. Banging or Clanking? That’s Not Good.
If you hear a loud banging, clanking, or thumping, it could mean a loose or broken part inside the compressor or blower.
What it might be:
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A loose motor mount
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A damaged fan blade
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A broken compressor part
Pro Tip: If the banging keeps happening, shut the system off and call an HVAC tech. Running it could make the problem worse and more expensive to fix.
2. Hissing Sounds? Watch Out for a Leak.
A soft or loud hissing sound could point to a refrigerant leak or air escaping where it shouldn’t.
What it might be:
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Leaking refrigerant line (can affect cooling)
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Leaky ductwork
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Faulty valve
In Greenville’s hot summers, a refrigerant issue can lead to poor cooling, higher energy bills, or even a frozen coil.
3. Squealing or Screeching? Likely a Belt or Motor Issue.
If your system suddenly starts squealing like a banshee, it could mean something’s wearing out.
What it might be:
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Worn blower motor belt
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Failing fan motor
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Motor bearings going bad
These parts aren’t always expensive to fix, but ignoring them can lead to full system failure.
4. Clicking Sounds? Could Be a Sign of Trouble Starting Up.
Some clicking is normal when the HVAC kicks on or off.
But if you hear repeated clicking, especially if your system doesn’t start, it could be:
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A faulty capacitor or relay
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Electrical control issue
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Thermostat problems
Electrical issues should be handled by a pro. Don’t try to DIY this one.
5. Buzzing Noise? Could Be Electrical or a Failing Motor.
A buzzing sound could mean:
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Electrical components are wearing out
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The condenser fan motor is going bad
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Debris is caught in the outdoor unit
Electrical buzzing should always be taken seriously especially during the hot Greenville summer when your system works harder.
6. Rattling or Vibrating? Something Might Be Loose.
If your outdoor unit is rattling or vibrating, check for:
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Loose screws or bolts
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Twigs or debris stuck in the fan
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A loose access panel
A quick visual inspection might fix this one. If not, it could be a sign the motor or fan is unbalanced.
Noisy Heating and Cooling Unit FAQs
Some minor issues like tightening a loose screw or clearing away leaves from your outdoor unit are homeowner-friendly. But when it comes to refrigerant, electrical, or moving parts, it’s safest to call a licensed technician.
Older systems tend to make more noise, but loud or unusual sounds are never “just age.” They’re usually a sign something needs repair or replacement.
Not always. Catching an issue early, like a belt replacement or capacitor swap, can cost far less than ignoring it and facing a full system breakdown.
When Should I Call for Service?
Here’s a good rule of thumb: If the noise is new, repeats, or comes with poor performance (like warm air, weak airflow, or high energy bills), it's time to call a HVAC company.
Don’t ignore weird HVAC noises. If something sounds off, it probably is. And in our hot, humid Upstate SC climate, you want your system running smoothly especially when summer’s in full swing.
Need a fast diagnosis?
Our team at Air Repair AL is local, licensed, and ready to help. We’ll listen (literally) and find the cause before it becomes a bigger problem. We will even offer some tips on how to prevent HVAC issues before they start.
Call 864-777-1111 for quick help if you are experiencing concerning noises from your air conditioning or heating system or contact us online with any questions.