AC Leaking Water? It's Usually the Drain — Act Before the Ceiling Does.
A Valley AC pulls gallons of water out of your air on a humid day, and all of it leaves through one narrow condensate drain. When algae and Phoenix dust clog that line, water backs up — and either your float switch shuts the system down (that mysterious 'AC just stopped') or the pan overflows into your ceiling. A tripped float switch is the system protecting your house: don't bypass it.
Ranked by Likelihood
Ordered by what we actually find on Valley service calls — start at the top.
What's most likely causing it
Clogged condensate drain line
Schedule service soonThe cause behind most water calls. Algae grows in the warm, wet line; dust binds it into a plug. Water backs into the primary pan, trips the float switch, or overflows. Monsoon humidity multiplies condensate volume — clogs that were 'fine' in May flood in July.
Frozen coil thawing
Schedule service soonIf the coil iced up (airflow or refrigerant problem) and then thawed, the meltwater can overwhelm the pan all at once. The water is the second symptom — the freeze is the real one. See the frozen-coil guide.
Cracked or rusted drain pan
Stop and callAttic air handlers past their 10th summer often have secondary pans that have rusted through exactly where you can't see. Water stains on the ceiling below the air handler with a clear drain line point here.
Safe checks before you spend a dollar
- If water is visibly pooling: turn the system OFF at the thermostat
- Check the secondary drain outlet (usually a small pipe over a window or eave) — water dripping there means the primary line is clogged
- If your air handler is in the attic, look for ceiling staining below it
- A tripped float switch = the AC won't run: that's by design; leave it until the line is cleared
When it's time to call
- Any water reaching drywall, flooring, or the ceiling below an attic unit
- The float switch keeps tripping after a line clearing
- Water plus ice on the lines (two symptoms, one visit)
- You're a ChampionCare member — drain checks are part of the visits; call before monsoon season peaks
Interactive
Answer three questions and get an honest read: likely cause, urgency, and the right next step.
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