Have you been dealing with air ducts making noise constantly in your home? The sound of air moving through your HVAC system is normal, but if you start noticing noise coming from AC vents such as banging, hissing, or buzzing, it might be an indication that your air ducts need some attention.
How to Troubleshoot Air Ducts Making Noise
In this guide, we will help you understand and pinpoint several common reasons for your air ducts making noise, while also providing simple DIY fixes that can help restore peace and quiet in your home.
Blocked or Closed Vents
How do you stop noisy air ducts? Checking for closed air vents is a good place to start! The sound of air struggling to pass through blocked or closed vents can create disturbing noise.
This blockage can occur when you’ve accidentally left furniture obstructing a vent or intentionally closed vents in a seldom-used room. Often, this is an overlooked issue that many homeowners might not consider when troubleshooting noise from their HVAC system.
Solution:
- Ensure all your vents are open and unblocked.
- This simple adjustment will not only reduce noise but also help the system work more efficiently, extending its lifespan and reducing energy costs.
Dirty or Clogged Air Filters
Air filters that aren’t replaced regularly may accumulate dust and debris, obstructing airflow and creating unusual sounds like thumping or high-pitched whistling. If overlooked, it can even lead to more serious damage to your HVAC system, compromising its efficiency and performance.
Solution:
- Regularly replace your air filters, preferably every 90 days, to ensure optimal airflow and noise reduction.
- This will also improve the overall indoor air quality, contributing to a healthier living environment.

Clean, Seal, and Insulate Ductwork
Why is my air vent making a lot of noise? Over time, dust and debris can build up in your ductwork, leading to airflow restriction and can give sounds like an air duct rattling noise.
Furthermore, unsealed ductwork can cause pressure imbalance, exacerbating the noise issue. Insufficient or non-existent insulation may also contribute to temperature fluctuations that cause metal ductwork to expand and contract, creating popping or creaking sounds. This can decrease the efficiency of your HVAC system and cause inconsistent temperatures throughout your home.
Solution:
- Consider having your ductwork cleaned, sealed, and insulated.
- Professional cleaning helps remove dust and debris, while sealing the ductwork reduces pressure differences and prevents air leakage. Insulation, on the other hand, helps dampen any noises caused by the metal ductwork expanding and contracting.
- Solutions can include acoustic duct liners, Aeroseal duct sealing, and fiberglass insulation. It’s important to always hire a professional for such tasks to ensure safety and efficiency.
Check Dampers and Actuator
The dampers within your ductwork are essentially valves that control the flow of air throughout the system. Improperly adjusted dampers can cause pressure imbalances and can lead to a loud popping sound from an ac unit or a loud banging noise from an ac unit.
Similarly, the actuator, which controls the opening and closing of the dampers, can also cause the same problem if not set correctly. Adjusting these components improperly can make the noise worse and potentially cause damage to your HVAC system.
Solution:
- Open the dampers on the supply side of your ductwork one at a time and see if this reduces the noise.
- Adjust the actuator inside the duct dampers up or down to help balance the pressure and reduce the associated noises.
- If you are unsure how to do this or if the noise persists after adjustment, it’s advised to contact your local HVAC technician.
Electrical Control Issues
A constant clicking sound from an ac unit might indicate issues with the thermostat’s electrical control or a system relay disruption. This can interfere with the efficient operation of your HVAC system and could potentially lead to larger, more expensive problems than your air ducts making noise.
Solution:
- To resolve this issue, it may be necessary to replace the old relay switch. However, due to the risk of electric shock, this should be done by a professional to ensure the safe handling of electrical components.

Motor Problems
Motor issues in your HVAC system may present as banging, rattling, or high-pitched squealing or screeching noises from an ac unit. Not only do these sounds disrupt your peace, but they can also signify serious issues that may lead to system failure if not addressed.
Solution:
- AC motor repair requires professional expertise to prevent further damage to the compressor.
- If you’re experiencing these kinds of noises, calling a professional should be your immediate course of action to ensure your HVAC system is thoroughly checked and repaired.
Compressor Malfunctioning
A malfunctioning compressor might create hissing or humming noises from an ac unit, indicating issues such as high compressor pressure or a strained compressor. This problem could severely impact the cooling capacity of your HVAC system and may lead to a complete system breakdown if not addressed in a timely manner.
Solution:
- Given the complexity of handling refrigerants and repairing the compressor, it’s necessary to call a professional in this case. This will not only ensure a safe and effective repair, but also potentially extend the lifespan of your system.
Even with these DIY fixes, there are some issues that may require an air duct repair professional’s touch. If your air ducts are still making noise even after you’ve checked for the common problems listed above, it may be time to call in the pros. At Dependable Heating and Air, we have an experienced team of professionals that can efficiently diagnose and repair your air ducts, ensuring your system runs smoothly and quietly. We are committed to providing you with the comfort you deserve and aim to deliver services that are both reliable and affordable.