Swamp Cooler and AC Leaks

Swamp coolers on roofs or in windows use a water supply line, a float valve and a pan. A stuck float or cracked pan can overflow onto the roof or into ductwork and ceilings below.

Central air conditioners make water that drains through a small line. If it clogs with algae, water backs up into the drain pan and can overflow into a closet, ceiling or crawl space.

Ceiling stains near vents or the cooler, water around the furnace or air handler, a musty smell when the system runs, and higher water bills in summer.

Have coolers serviced in spring and drained and covered in fall. Flush AC condensate lines with a cup of vinegar each month in summer, or as the manufacturer suggests.

A cooler supply line left full in winter can freeze and split, leaking into the attic. Shut off and drain it before the first freeze.

A float switch on the AC drain pan shuts the system off if water rises. It is a small, cheap part that prevents ceiling leaks.

Turn the system off, catch drips, photograph and call. See drying and dehumidification.

Leaks into ducts and ceilings are dark and warm, which suits mold. Dry quickly.

Coolers on the roof sit above the attic. A leak there soaks insulation and ceiling drywall before anyone sees it. If you have a roof cooler, look in the attic around its duct each spring and after any summer storm.

Coolers work by adding moisture. Running one with every window closed can push indoor humidity high enough to cause condensation and mold. Crack a window or two so moist air can leave.

The air handler and furnace often sit in a closet or the crawl space. Check the floor around them each month in summer for water from the condensate line or pan.

An HVAC technician fixes the unit or drain. If water has soaked a ceiling, floor or crawl space, call a restoration provider to dry it.

Spring start-up and fall shutdown are the two moments to look closely. Make them part of your seasonal routine.

Dark stains on the attic floor around a cooler duct, damp insulation or a musty smell in the attic point to a leak. Check after the first hot week of summer.

Old cooler pads clog and push water where it should not go. Replace pads each season and check the pan for cracks or rust. A pan that leaks drips onto the roof or into the duct.

Some AC systems use a small pump to move condensate water to a drain. If the pump fails, water overflows. A pump that hums but does not empty, or water around it, means it needs replacing.

Water that gets into ducts can drip from ceiling vents. If you see drips at a vent when the cooler or AC runs, turn the system off and call.

Sudden overflow damage is often covered; long-term leaks may not be. Regular service records help show the unit was maintained.

Before turning on a cooler for the season, check the pads, the pan, the float valve and the supply line. Turn the water on and watch for a few minutes for drips or overflow. For central air, check the drain pan and condensate line and pour a little water in the pan to confirm it drains.

Shut off the water to the cooler, drain the pan and line, and cover the unit. Close any damper so cold air does not come down the duct. For central air, nothing needs draining, but check the pan is empty and dry.

Coolers and air conditioners make summer comfortable, but their water lines and drains need two checks a year. A few minutes in spring and fall prevents most ceiling stains and wet closets.

If the furnace and air handler sit over the crawl space, a condensate overflow can drip below the floor for weeks. Check under the house near the furnace a few times each summer.

An HVAC technician fixes coolers, pans and drain lines. For wet ceilings, walls or crawl spaces, a restoration provider dries the house so the leak leaves nothing behind.

Two seasonal checks, spring and fall, prevent most cooler and AC water damage.

Questions about swamp cooler and ac leaks? Call (208) 923-0564 to reach a local Caldwell provider, 24 hours a day.