Your air conditioner produces 1-5 gallons of water per hour in humid climates. That water drains through a small PVC pipe to the outside. When that pipe clogs — and it will — gallons of water have nowhere to go but into your ceiling, walls, and floors.
Insurance companies estimate that HVAC-related water damage costs U.S. homeowners $2.5 billion annually. It's the most common and most preventable home disaster.
How Much Water Does Your AC Make?
Use our condensate calculator, but here are the basics:
- 2-ton system in Houston: ~1.5 gallons/hour
- 3-ton system in Miami: ~2.5 gallons/hour
- 5-ton system in New Orleans: ~4+ gallons/hour
That's 20-40 gallons per day during peak summer. All flowing through a 3/4" PVC pipe. When algae, rust, or debris blocks that pipe, the overflow starts — silently, in your attic, where you can't see it.
Warning Signs
- Water stains on ceiling below the AC unit
- Musty smell near return vents
- AC shuts off randomly (float switch triggered)
- Dripping or pooling water around the indoor unit
- Higher than normal humidity indoors
The 5-Minute Fix
- Find your condensate drain line (PVC pipe exiting your house near the outdoor unit)
- Pour 1 cup of bleach or vinegar into the access port every 3 months
- Use a wet/dry vac on the outdoor end to clear any blockage
- Install a safety float switch ($15) if you don't have one — it shuts off the AC before overflow
- Check the drain pan under the indoor unit for cracks or rust
If your system needs a condensate pump (basement or attic installations), use our sizing calculator to get the right one.