We have a small pvc pipe in the ceiling of our garage. It’s been dripping lately and I’m not sure if it’s because we are using the a/c more or if it’s because it’s been raining the past week. Can anyone tell me what this is dripping from or what I can do to fix the issue?

  • 4
    Picture will help. Right now it could just be a piece of pipe put up there for storage, a water pipe or a drain pipe.
    – crip659
    Aug 1, 2022 at 21:15

1 Answer 1


My guess is that your AC unit is in your attic, somewhere near this small PVC pipe. It's likely from the auxiliary drain pan underneath your AC unit. Under normal circumstances the AC has a primary pipe that drains the condensation away to a normal drain somewhere in your house that you probably never see. But if that primary drain pipe gets clogged, the AC will overflow and the water will run into the auxiliary drain pan, which typically gets routed to an obvious place that the homeowner would see and pay attention to.

It's likely that your primary drain line is clogged, and the dripping you're seeing is a warning to that situation. The solution is to go up into the attic and clean out the primary drain line (or hire a professional to do it). It's not hard to do, but could be a challenge, depending on what access you have to your AC unit.

The auxiliary drain pan is basically preventing that condensation from causing water damage to whatever is below your AC unit, likely walls/ceilings, etc.

  • My primary drain line clogged and the water went out the drain vent (which was very short) and then travelled on the OUTSIDE of the sloped drain line for about 30' before it dripped off onto our foyer ceiling.
    – RetiredATC
    Aug 1, 2022 at 22:10

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