5 AC Noises and What They Mean

As technology progresses, air conditioning systems are quieter than ever before. That’s why it’s majorly concerning when you hear some unexpected noises coming from your AC unit. These noises could be coming from the AC unit itself, or the condenser—either way, they shouldn’t be ignored. Since AC season is just around the corner, here are 5 AC noises and what they mean.


As we’re sure you know; screaming isn’t just for horror movies. Screaming or screeching sounds can come from your home air system, and when it does, it shouldn’t be ignored. If you ever hear screaming coming from your AC system, turn it off right away. One of the main causes of a screaming AC unit is a refrigerant leak. Refrigerant leaks can cause monumental damage to your AC and could potentially harm your health. Another reason for a screaming AC is high internal pressure. Either way, screaming is an AC noise you shouldn’t ignore.


If you hear any clicking when you first start or stop your system, that’s not a cause for concern. The issue is if you hear the clicking while your system is running. Clicking could indicate an issue with the thermostat or the electric system in your AC unit. While clicking isn’t catastrophic, it’s better to have the whole thing checked out so small problems don’t turn into bigger ones.


If something is loose or broken, it’ll make a banging sound. Oftentimes, you can blame a loose, or completely separated, connecting rod, piston pin, or crankshaft on this AC noise. If you hear banging, turn off your AC and wait for your HVAC technician. They can help diagnose the problem and pinpoint where the banging is coming from, what’s causing it, and what can be done.


Just like how cars squeal when there’s a loose belt; AC units will do the same. If you hear a loud squealing it means the fan belt is worn or incorrectly aligned. If you only hear the squealing from time to time, please note that humidity levels can cause a fan belt to expand or contract, which will make it go off kilter. If you hear squealing you can keep your AC unit on and working, but call an HVAC technician ASAP, you don’t want this small problem to turn into a large, expensive one.


If you hear a buzzing or a humming coming from your AC unit or condenser, it could mean a few things. It could indicate the compressor isn’t working, or the electric is running too hot. Another reason for a buzzing AC noise is that the little rubber feet on your condenser are getting old and worn out. This will cause the condenser to shake and buzz. Buzzing could also be a sign of loose parts or a refrigerant leak. Either way, when you hear the buzz, it’s time to call your HVAC technician.

Hearing Any of These AC Noises? Call Moore Home Services

Are you hearing any strange sounds coming from your air conditioning system? Don’t hesitate to call the experts at Moore Home Services. We are a Diamond Certified company happily serving Santa Rosa, Marin County, and surrounding communities. Our HVAC technicians and plumbers are on hand for any issues you may have. Reach out to our friendly call center representatives today or click here to request an appointment online.