Leaks & sources
Swamp cooler leaking through the ceiling: causes and fixes
Updated
Short answer
A swamp cooler usually leaks through the ceiling because its float valve stuck and overfilled the pan, the pan rusted through, or the seal where the duct enters the roof failed. Turn the cooler off, close its water supply, and check the ceiling and attic for wet insulation.
Stop it now
- Turn the cooler off at the thermostat or wall switch.
- Close the cooler's water supply valve — often in the attic, laundry, garage or at a hose bib.
- Put a bucket under the vent and move furniture.
- If the ceiling sags, keep people out from under it.
Common causes
- Stuck float valve overfilling the pan
- Rusted or cracked pan
- Cracked roof jack seal or flashing around the duct
- Clogged bleed-off or overflow line
- Pump or distribution line leaking inside the cabinet
Is the ceiling ruined?
A small damp area caught quickly can sometimes be dried in place. Sagging drywall or soaked blown-in insulation usually needs replacement. The attic side of the drywall can grow mold in a warm attic, so it's worth having it checked with a moisture meter.
Preventing it
- Service the cooler every spring: float, pads, pump, pan and lines.
- Coat or line the pan to slow rust.
- Inspect the roof seal around the duct.
- Drain, disconnect and cover the cooler every fall.
Questions
Can I keep using the cooler if it's leaking?
No. Every hour it runs adds water. Fix the float or pan first.
Does insurance cover a swamp cooler leak?
A sudden failure may be covered; slow leaks and maintenance issues such as a rusted pan often aren't.
Who fixes the cooler?
A cooler or HVAC technician repairs the unit; a roofer fixes the roof seal; a restoration company dries and repairs the interior.
Editorial note: this guide is general information for Arizona homeowners, not professional, legal or insurance advice. For your situation, talk to a licensed contractor and your insurer.