Why is my air vent leaking water? (2023)

Why is my air vent leaking water?

A refrigerant leak causes AC vents to leak water in almost the same way a dirty air filter does. When refrigerant levels are low, your AC unit cannot remove the humidity from the air inside properly. Water that is sucked out of the air can remain on the evaporator coils too long, and freeze over.

The AC Drain Line is Clogged

The problem: A clogged AC drain line can cause water to accumulate within an air vent. Similar to your air filters, over time the drain line can get clogged with dirt, dust, mildew, bugs, and debris and needs to be unclogged to work properly.

If the AC system wasn't installed properly, either the unit or the drain pan might slightly tilt to one side, causing pooled condensation to drip. If you've had your air conditioner for years and this is the first time it drips, this is likely not the issue.

Condensation usually occurs when warm, moist air contacts a cold surface. Moisture will form on the cold surface and drip down. You often see it on old metal windows that are not made with insulated glass. The way to avoid condensation is to keep the warm air away from the cold surface.

Wrapping your AC ductwork is an effective way to prevent condensation. Duct wrap has a foam insulation inner layer and a foil outer layer. Cleanly wrap it around the AC duct and fasten with duct tape near the joints.

Assuming that the leak is caused by blockage or dirt buildup, you should be okay to keep using it. Keep a bucket below the leaking AC unit and continue to monitor your AC for any other signs of damage.

Air duct “sweating” forms when the warm air from outside collides with the cold of your A/C ductwork. The colder your A/C, the more condensation will form on your air ducts.