6 Common Causes and Solutions to a Leaking AC Vent

Have you noticed some water pooling under your air conditioning system? This could be due to several reasons. Three among the causes of an AC vent leak include a dirty coil, clogged drain line, and a clogged air filter. We discuss below, the 6 common causes of an AC vent leak and how to fix them.

A Dirty Evaporator Coil

Your AC works to cool your home in a variety of ways, one of which is by pulling humidity from the air. The unit’s cold evaporator coil works by collecting this condensation and draining it away, and when everything is functioning as it should, the water from the system runs down this coil into a pan, leading to another drain. This collected water eventually accumulates in your plumbing drain or at some point, outside the house.

One of the most common reasons why coils malfunction is due to dirt, once it gets coated in dirt, mold, dust, or other debris, the water’s no longer bonded tightly enough to its surface. This makes the AC vent leak, and in turn, the water creates a bond with the dirt and grime. The dirt and grime product then mixes with condensation puddles on an interior’s floor.

A dirty evaporator coil can be problematic. It affects the water it manages by preventing it from diverting into the proper drain, and as such dirt gets carried through the system and leads to clogged drains. Moreover, once they’re completely blocked, the water won’t have anywhere else to go but back into your house. To prevent this issue, you need to have yearly inspections, clean your furnace and central humidifiers, along with the coils.

Clogged Drain Lines

Once you have identified a clog, you can use a wet or dry vacuum to get rid of obstructions. Every 4–6 months, after you’ve made sure that the pipes are clear, pour a mixture of half bleach and half warm water down the drain line.

This is necessary to ensure that the drain stays clear of mold and other growths. It also helps dislodge any other impediments. If you observe that clogged drain lines continue to be a problem, you may have to install an overflow shut-off device on your drain line to help minimize future damage by allowing your AC to shut off automatically if the drain backs up.

Clogged Air Filter

For your indoor air handler to work smoothly, it needs proper airflow. If there is a clog in the air filter, the air gets restricted, and that leads to different problems, one of which is the issue of frozen evaporator coils dripping excess water. How can you tackle this problem? Change your air filter every 30–60 days.

A Damaged (or Corroded) Overflow Drain Pan

Over time, drain pans made of metal or plastic can corrode, leading to further leakage. Get a flashlight to have it inspected for holes or cracks, and then replace if there is a need to.

Problems from Installation

It’s crucial to bear in mind that poor installation practices result in a variety of problems, many of which cause water leakages inside the house. Sometimes, drain pipe fittings without proper installation loosen over time, thus making the condensation drain onto the floor. Also, the air conditioning unit may not be completely level, or there could be too much pressure; this can equally lead to pooling water on the ground.

Extensive Water Damage

Condensation line leaks take place within walls and low traffic areas such as attics and basements. This implies there may have been the presence of standing water over a long period even if you’ve noticed, and now, trying to address the problem. Repairing extensive water damage can cost you thousands of dollars, that’s why it is crucial that you inspect your HVAC regularly and frequently.

Contact General Air Conditioning Services Corporation — Your Local HVAC Contractor in Greenville

To prevent an AC vent leak, our well-trained and experienced professionals will include the yearly inspections, cleaning the furnace, and central humidifiers, along with coils as part of your comprehensive annual AC system maintenance visit.


For all your HVAC needs in Greenville, SC, General Air is the go-to service provider. We have been rendering full-scale HVAC services to satisfied customers since 1969. Whether you need to upgrade your system, have an existing system repaired or replaced, or you wish to purchase a brand-new system, kindly call General Air on 864-633-5664 to schedule an appointment!

Share on facebook
Share on twitter
Share on linkedin
Share on reddit