If the furnace is the heart of your home, then your air ducts are the veins, sending air from room to room, filtering out dust and other particles, and ensuring even distribution of heat (or, when the AC is running, cold) and proper home airflow.

When your air ducts are leaking, it can cause all sorts of problems. Fortunately, there are a number of symptoms that you can use to identify leaky air ducts. Better still, there are a number of ways you can fix an air duct leak yourself – you don’t always need to call a contractor.

The symptoms of leaky air ducts

You may have noticed that heating and cooling in your home seems uneven from room to room. You may also have noticed that air seems stale in certain areas. These are both signs of leaky air ducts – but they’re also signs of other problems.

Before pointing your fingers at the air ducts, check:

  • That your filters are clean – replacing them if needed
  • That all of your grilles and registers are open

If you’ve checked the above and stayed on top of regular maintenance, it’s probably the air ducts. Other signs of leaky air ducts include:

  • Kinks and twists in the ductwork
  • Holes in the ductwork (often accompanied by the sound of air escaping)
  • An unexplained increase in your energy bills

Note that an increase in your energy bills alone is not a reason to suspect ductwork problems – you may also have insulation or appliances that are getting too old to be energy efficient.

Finding the duct leaks

There are two routes for finding leaks in your air ducts – the DIY route, and the hire-a-contractor route.

The advantage of the first route is easy to understand: it’s free. The disadvantage is that it’s going to take some time and some elbow grease – and you might still need to hire a contractor at the end of the day.

With that said, let’s look at a couple of DIY methods you can use:

Visual inspection

This is pretty straightforward. Follow along the ductwork in your home, and take note of any holes, twists, kinks, or hissing sounds. You’ll patch them later. When doing this, make sure to run your furnace or AC full blast, so that any leaking sounds will be more noticeable. Don’t stop after finding one leak, because you may have multiple.

Smoke inspection

The smoke method is similar to the visual inspection, in that you’ll follow along your ductwork taking note of any holes. This time, though, you’ll carry around incense or a smoke pen, and take note of anywhere that the smoke moves in unusual ways. This is a sign that air is blowing out of or being sucked into a hole in the ductwork.

We won’t go into the hire-a-contractor method – look for a reliable HVAC contractor, then hire them. Simple as that. They’ll also be able to help you if there are places your ductwork goes that you can’t get to.

Repairing duct leaks

Now that you’ve found the leaks in your ductwork, it’s time to repair them. This process will involve sealing the holes with either mastic sealant or metal tape – duct tape, surprisingly enough, is not the go-to tool for these repairs.

In many cases, this is all you’ll need to do – and it’s among the simplest DIY projects you can find.

You may, however, need to call a contractor in a couple of cases. If you see a number of holes or kinks in your ductwork, or if there are some areas that you find impossible to reach, an HVAC technician can help.

What’s the best time to replace your AC? Some say it’s in the spring. Some say it’s when you need repairs. We say one of the best times (the other two included) is when you need to get your air ducts repaired.

In some cases, you’ll need to add on to your existing air ducts when you’re getting a new AC system anyway. That makes it easy to replace your ductwork when you get a new AC system. New ductwork tends to be more energy-efficient, too, so you’re sure to get the most out of your new system.

And now you know everything you need to about diagnosing, finding, and repairing duct leaks! We hope this helps you.