AC Leaking Water Inside the House: Causes and Fixes
Water under the air handler, a stain on the ceiling under the attic unit, or water in the garage near the furnace almost always means the condensate drain is blocked. In Las Vegas, with units in hot attics and garages, it is a summer regular.
Why it happens
An air conditioner pulls moisture out of the air and drains it through a small PVC line. Dust, algae, and sludge clog the line; water backs up into the drain pan and overflows. Many systems have a float switch that shuts the AC off when the pan fills, which is why a leak often shows up as "AC stopped working" first.
Right now
- Turn the system off at the thermostat to stop more water.
- Put a pan or towels under the unit; look for the secondary drain line outside (a short pipe near the eaves) and see if it is dripping, which means the primary is blocked.
- Do not pour bleach into the line unless you know which end is which.
What it costs
| Fix | Las Vegas range |
|---|---|
| Clear the condensate line and test the float switch | $100 to $250 |
| Replace a cracked or rusted drain pan | $250 to $600 |
| Frozen coil from a dirty filter or low refrigerant (thaws and leaks) | $100 to $1,500 depending on cause |
| Ceiling drywall repair after an attic leak | $300 to $1,000, usually a separate contractor |
Prevention
A drain flush is part of every real tune-up. If your unit is in the attic, ask about a secondary pan with its own float switch; it is cheap compared to a ceiling.
Water coming from the AC?
We introduce you to licensed Las Vegas heating and air companies. Free for homeowners.
Get matchedWe introduce you to licensed Las Vegas heating and air companies. Free for homeowners.
Related answers
- AC Blowing Warm Air in Las Vegas: Causes and Repair Cost
- AC Won't Turn On: What to Check and What It Costs to Fix
- Heater Not Working in Las Vegas: Furnace and Heat Pump Fixes and Costs
- Repair or Replace the AC? How Las Vegas Technicians Decide
- AC Capacitor Replacement Cost in Las Vegas
- AC Tune-Up Cost in Las Vegas and What a Real One Includes