
You've got water pooling around the furnace, dripping from the attic, or staining the ceiling. Nine times out of ten it's the condensate drain.
You probably came here because…
- Water puddle around the base of the furnace or air handler
- Wet spot or brown stain on the ceiling under an attic unit
- Rust developing on the bottom of the furnace cabinet
- The AC keeps shutting itself off (float switch tripping)
What’s actually happening
When your AC runs, it removes moisture from the air. That water drains out through a small PVC line that goes to a floor drain or outside. When that line clogs with algae or debris, the water has to go somewhere – and that somewhere is your floor or ceiling.
Modern systems have a float switch that shuts the AC off when the drain pan fills up. That's a safety, not a fix. If the AC keeps cutting off, the drain is clogged.
The other possibility on attic units is that the drain pan itself has rusted through. That's a bigger job because the pan is under the coil.
What we do about it
Find the drain line
Look for a white PVC pipe about 3/4 inch coming out of the side of the furnace or air handler. Follow it to where it terminates – either a floor drain, a utility sink, or outside the house.
Clear the clog
You can use a wet/dry vacuum on the outside end of the line to suck the clog out. Or you can pour a cup of white vinegar in the cleanout tee (that vertical PVC piece with a cap) to kill algae. Both work.
Prevent it from happening again
Pour a cup of vinegar in the cleanout tee every spring. Some systems have a tablet holder in the drain pan – a $5 pack of algae tablets lasts a year.
When to just call
If you can't find the drain line, if the leak is coming from somewhere other than the drain (like a rusted-through pan), or if water is already staining drywall, call (423) 637-1846. Drywall repair is expensive – a service call is cheap.
Ready to fix it?
Call the family that’s been doing this in the Sequatchie Valley since 1996.