9 Signs Your Air Ducts Need Repair

person cleaning the air duct

Air ducts, like every other part of your home, need repairs every so often. A damaged duct system can lead to serious problems, such as water damage or even the ductwork collapsing. Therefore, it’s important for homeowners to recognize signs of air duct damage, such as odd smells or temperature pockets, so that they can make repairs as soon as possible. Below are 9 signs that your air ducts need repair for you to look out for.

Signs Your Air Ducts Need Repair

Signs of air duct damage can be subtle, but they’re not overly hard to recognize if you know what you’re looking for. Among other things, you should watch out for altered airflow, odd noises or smells coming from the vents, pockets of hot or cold air, and pests. If you suspect that your air ducts are damaged, you shouldn’t wait to get them inspected, for the sake of both your indoor air quality and your utility bills.

1. Weak Airflow

One of the number one signs that your air ducts aren’t working properly is reduced airflow from your vents. This is a sign that there’s a hole somewhere in the ductworks, or in the case of flexible ducts, that there’s a kink or compression somewhere. However, it can also be a sign of a dirty air filter or vent. Clean the vent or replace the air filter, and if the problem persists, look into professional help.

2. Strange Noises

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Odd noises are a pretty good indicator that something’s not right in your duct system. Any banging, clanging, bumping, or other noise that you don’t typically hear from your HVAC system, is a sign that you need to take a look at it. In particular, if you hear anything that sounds metallic, that likely means that some metal parts are grinding together and will need to be replaced soon.

3. Odd Smells

Another sign of damage is odd smells coming from the vent. A musty, dusty smell is fairly normal, if not pleasant, for a ventilation system due to the amount of dust that builds up in the air ducts. However, if you smell mold or mildew, you should find a professional to take a look right away. Mold in your ductwork can cause health problems, particularly in people with asthma or another lung issue.

There are also other smells to look out for. If you smell burning coming from the vent, it’s a sign that there’s an issue with your fan belt, especially if it’s accompanied by a squealing noise. 

If the vents smell sweet, it’s possible that your HVAC system is leaking refrigerant. Really, any smell that’s out of the ordinary is a cause for concern. An HVAC company will likely be able to tell you in detail what individual smells mean.

4. Humidity

By design, an HVAC system will eliminate humidity in your home’s air. If you’re noticing that your home is more humid than it usually is, even if only in certain rooms, that’s a clear sign that something isn’t right with your air conditioning system.

Specifically, excess humidity indicates an issue with your HVAC’s evaporator coil. The evaporator removes water vapor from the air through condensation, and then drains it out through a pipe to the outside. If the evaporator isn’t doing its job, the extra humidity can seriously damage your home through mold or rot.

5. Temperature Pockets

If there’s pockets of cold air when your thermostat is set to heat, or vice versa, that’s a pretty good indication that you need to take a look at your HVAC system. Although it can be a sign that something’s wrong with your insulation, it’s also indicative of poor airflow in your ductworks. Any number of causes could restrict the airflow, few of them pleasant, so talk to a professional to get to the bottom of the issue.

6. Leaks

If your HVAC, ducts, or vents are leaking water, it’s a pretty good indicator that something needs to be repaired. Most likely, it’s an issue with the condensation pipe or pump, but it could also be something more serious.

Your HVAC may also leak refrigerant, which is the substance it uses to condition the air and remove humidity. If this is the case, it’s a much bigger issue than leaking water. Breathing it in can cause serious health issues, so if you suspect it, turn off your HVAC, evacuate, and schedule an emergency visit from an air conditioning professional.

7. High Utility Costs

person cleaning the air duct
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Energy costs will fluctuate throughout the day. You can expect to pay more to cool your home during the warm seasons, and to cool it during the heat. However, if you notice that your energy bill is higher than normal, it could be a sign that something’s wrong with your ductworks.

Leaks, restricted airflow, and more can make your ductwork less efficient and therefore make your HVAC work harder. It’s not too serious an issue, but it is wasted money and decreases energy efficiency, so it’s worth getting it checked out.

8. Pests

A pretty good indicator that you need to call a duct expert is any signs of pests. Rats can chew holes in your ductwork, which will lead to serious problems. Almost any other pests can do similar damage, especially if you have flexible ductworks. Rodents can also leave behind droppings or bacteria that you most certainly don’t want in the air you breathe.

If you suspect you have a pest problem, your first call should be to an exterminator. Once they’ve done their work, it’s time to call in an HVAC technician to assess the damage. If you’re lucky, the pests limited themselves to the ductwork. If you’re not, it’s possible they damaged your refrigerant lines or other important components.

9. Buildup

air ducts full of dust
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A sign of duct damage you may not consider is dust buildup. If you have significant amounts of dust on your air vents, it’s a sign that something’s wrong with the filter in your ductworks. This is especially true if the air filter on your vent looks clean but the vent itself is dirty.

If this is the case, your HVAC could be experiencing buildup of dust or other contaminants that could eventually inflict damage. It can also lead to less efficient ducts and higher energy bills for you. Thankfully, it should be relatively easy to solve; a filter replacement or repair and an air duct cleaning will, with any luck, set your ductwork right.

On a similar note, mold or mildew is another good sign that your ducts need repairs. Even the smell of mold is an indicator that you need to call a professional. Not doing so can lead to health problems for the inhabitants of the house, as well as an even greater problem down the line that will cost even more to take care of.

FAQ About Air Duct Repair

How often should I replace my ductwork?

On average, a duct system lasts for about 10 years before it needs to be replaced. Keep in mind that this applies to the ducts themselves; an actual air conditioning unit and the HVAC system as a whole have different lifespans.

What causes air duct problems?

Air duct issues can have any number of causes. Here’s a short list of possible causes for your air duct problems:

  • Lack of maintenance
  • Pest infestations
  • Debris
  • Poor sealant
  • Leaks
  • Kinks or compressions

Can I repair my own ductwork?

It’s not recommended to DIY duct repairs. It’s not an easy process, and doing it wrong can have serious consequences for your HVAC system. Unless you yourself are a licensed and trained professional, it’s best to find a professional to do it for you.

Find a Duct Expert

Home repairs are a sad necessity. When your air ducts need service, you shouldn’t hesitate to get them worked on. Otherwise, you may experience a reduced quality of life, and you risk serious damage to your home in worst-case scenarios.

When your HVAC system needs repairs, contact your local HVAC experts. They can help you with your air conditioning, heating, and ventilation needs so that you don’t have to worry about them.

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Austin Geiger

Austin Geiger is a writer who's passionate about home care. He enjoys writing about home maintenance practices, as well as projects to turn an outdoor space into a backyard paradise.