A Complete Guide to HVAC Noises and Their Meaning

By January 10, 2022December 15th, 2023No Comments
HVAC noises

When your HVAC is working well, you probably won’t realize it’s even in the house. When you hear HVAC noises such as thumping, rattling, and squawking, you know there’s trouble. To help you determine if it’s time for Texas HVAC repair, we’ll go over the most common HVAC sounds and what they mean.

HVAC problems only get worse when they are left alone. Problems with your HVAC can also lead to indoor air quality issues. To help keep your system up and running, we’ve rounded up everything you need to know about a broken HVAC system and sounds to watch for.

Screeching or Squealing

If your HVAC system is starting to sound like nails on a chalkboard, it could be a sign of air conditioner problems. This usually signals parts moving in your AC unit. These parts are breaking and becoming worn out.

A belt could need replacing or a motor bearing has come off-center. These will both cause a painful squealing and screeching sound. We can take a look and assess where the sounds are coming from. In the perfect scenario, we can fix the problem easily before they completely stop working.

Let us check out and inspect your HVAC system before a small problem becomes a big one. We can get in and get your system back up and running. Don’t try and fix screeching with an oil or another do-it-yourself solution.


There are a number of reasons your AC unit could be rattling. One common reason is that a part has come loose. You need a professional to repair it before the loose part comes off completely. If the motor has become damaged, this will also need to be taken care of by a professional.

Loose panels are another common reason for rattling. The panels and doors on your unit should be attached firmly. If they aren’t, the loose screws will cause a rattling sound.

Debris caught in your HVAC system can also cause a rattling sound. Cleaning your AC unit will help keep your air clean and improve your indoor air quality. We’ll inspect your AC unit and see if a twig or something else has become stuck.

HVAC System is Thumping

While it’s normal for your air conditioner to make a thumping noise when it powers down, a continuous thump is a cause for concern. If you are constantly hearing thumping noises, it’s time to give us a call.

When the filter is hitting the duct cover also known as the return grille, you may also hear a thumping sound. This could also mean there is a hole in the ductwork or that you have a broken seal. We’ll inspect both to find the cause of the thumping and repair it.

If you hear a thumping noise from the outside you may also have a problem on your hands. If your compressor springs are broken, or the fan is banging against metal, you’ll hear a thumping sound. One key thing to listen for is if the thumping is getting louder. This indicates a problem that should be addressed by professionals.


A thwapping sound is similar to playing cards being shuffled. This could mean something is stuck in the blades of your blower or touching it from the inside. This noise may not be an emergency immediately but if it isn’t addressed, your motor or belt could wear out.

If you hear a thwapping noise, give us a call to have an inspection done. The longer the problem persists the more serious it could become. We’ll find the source and get your system back in working order.

Repeated Clicking

If you hear a clicking sound that keeps repeating, this could be a sign that there’s a problem with the relay process. This process regulates the air temperature in your home. This is a very important function that you don’t want to ignore.

An electrical problem could also be the cause of the clicking. This electrical problem could cause the relay to stop working. Before the problem becomes more serious, give us a call.

The contractor is the connection between the compressor and the thermostat. If you hear a repeated clicking this connection could be damaged. Let us inspect it to see if you’re in need of a replacement.


A buzzing noise from the outside of your HVAC unit is a sign that you have a refrigerant leak. This could mean it’s getting used too often. If you turn off your air conditioner and give it a break, you may hear the buzzing subside.

If you’re constantly hearing buzzing even after giving your AC a break, you’ll want to have us inspect it. This isn’t something that should be happening often.

Buzzing could also indicate a problem with your condenser fan or with the electrical. Buzzing is always something that shouldn’t be ignored.

Loud Banging

If your air conditioner is running and you hear loud banging, this is a sign that it needs to be repaired. You could have a damaged connecting rod or a piston pin. Banging could also mean it’s time to replace your compressor.

If you hear a loud banging, you should shut off your AC unit and give us a call. We’ll come in and inspect and repair it before you use it again.

It’s Time to Call a Professional About Your HVAC Noises

If you hear any of the HVAC noises above, it’s time to give us a call. We’re ready to serve you in the Forney, Texas, and surrounding areas. From Forney, Mesquite, Kemp, Rockwall, Kaufmann, Terrell, and Maybank, were are your air conditioner repair specialists.

If you’re ready to book your service appointment, fill out the contact form here. We’ll find the source of the noise and get your air conditioner back up and running.