Home > HVAC > Why Are My Air Ducts Clogged and How to Fix It?

If you don’t know much about HVAC, any problem with your air ducts can seem intimidating. But if your building suffers a few symptoms (below) of clogged ducts, there are a few common causes for it.

First, here are a few ways to tell if your air ducts could be clogged:

  • Are temperatures in different rooms of your building not the same?
  • Has your energy bill spiked up recently? More than what would be expected with seasonal changes?

The biggest symptom of clogged air ducts is differing temperatures throughout your building. This is because if your have a particular air duct that is clogged, then air is only cut off to some rooms in the building, but not all of them. And, unfortunately, since that room cannot reach the temperature you’ve set on your thermostat, your HVAC system will continue to work harder and harder to cool or heat that room properly.

To narrow down which ducts are clogged, turn your HVAC on and go to each room. Put your hand in front of the vent to see which ones are blowing air and which are not.

Then, try the following to decide whether or not your air ducts are clogged and how to fix them!

  • Initially, make sure none of your furniture or wall hangings (or holiday decorations) are covering any of your vents. Dust them as well! If a lot of dust gathers on your vents it could block the full amount of air from leaving the duct.
  • Check your air filters. They should be changed regularly, but mistakes happen and we can forget. That’s the best place to check because if they are dirty and clogged they can prevent airflow or even cause your HVAC system to circulate dirty air through your whole building–yikes! Typically your air filter should be changed every month or two depending on the type of filter.
  • Another possibility is leaky or damaged ductwork, you can check for this by using a flashlight and looking as far down your air ducts as possible. You’re looking for any loose seams or openings in your ducts. It’s pretty common for ducts to disconnect, which leads to damage. You should call an HVAC technician in the case of an opening or disconnection in your ductwork. They are trained to suggest the best method of fixing it.
  • A part of your HVAC system that you may not be familiar with is the zone dampers. These control the way the air flows in your building. They should always be completely open, but sometimes they can get stuck closed or they can wriggle loose completely on their own. Check them, they are accessible and you can adjust them manually. If they’re closed, it will completely obstruct the air from that duct and affects the airflow in your entire building.
  • If none of the solutions above have helped, you could have an obstruction in your air duct. It could be anything from dust, dirt or debri, to pieces of old air filter or ductwork insulation. Or even bugs! If you find anything blocking your ducts, remove it immediately. And if you don’t feel comfortable removing it yourself, then call us and we can perform a tune-up for your whole system and clean out your air ducts.

While these are simple fixes for common HVAC system problems, if you don’t feel comfortable checking your vents yourself, we are always happy to help our customers and make sure your HVAC system is working to its full potential.