I remember the first time I looked up at an HVAC vent in my living room and noticed a light brown stain. At first glance it looked like maybe it was a shadow or even some dust stuck to the ceiling. However, upon inspection it was a stain. More specifically, it was a water stain caused by poor insulation around the air ducts. 

In this post, we’ll look at some of the main causes of water stains around your HVAC vents along with what you can do to fix the problem and remove the stain.

Main Causes of Water Stains Around HVAC Vents

As mentioned above, a water stain around your vent is an indication of escaped moisture. This is a direct result of a problem with insulation. The most common causes are air leaks and lack of insulation.

Condensation is a byproduct of all HVAC systems. Condensation is the result of the warm air in your home’s attic mixing with the cool air traveling through your HVAC system’s ducts. When properly insulated and maintained, excess water is removed from the air and exits your house through a drain line. 

Myrtle Beach summers are very hot and humid, so there is often a lot of condensation during months with high AC use. When there are gaps or leaks in duct insulation, water droplets drip from your attic to your ceiling. Over time, these drops will create stains and ruin drywall.

Stains that are around HVAC vents indicate an insulation problem around the part of the duct that attaches to the vent. This is commonly known as the “boot.” Poor insulation and boot fitting create opportunities for condensation to escape. When water drips around the vent, you’ll notice the dark stain on the ceiling near your AC vents. 

Fixing Water Stains Around HVAC Vents

Since the stain is a symptom of an insulation or vent fitting problem, it’s wise to call an HVAC professional to fix the root issue. Adding insulation and refitting the duct boot is a relatively common service call. Once fixed, it’s time to take care of the stain.

Get rid of water stains by applying a coat of Kilz primer and then a coat or two of paint to match your ceiling. 

For professional and affordable HVAC service, call Cooper Mechanical Services today. Our team is knowledgeable, courteous, and quick to solve problems with the latest technology include thermal imaging for hard-to-find leaks. To schedule a service call, simply Call Cooper.