Water leaking from American Standard indoor air handler or furnace cabinet during cooling

Safety first: Turn off power to the indoor unit to avoid electrical hazards around water.

• Clear the drain line: Locate the PVC drain exiting the air handler. Use a wet/dry vacuum on the outside termination to suck out algae and debris. Alternatively, use a condensate drain cleaning tool or compressed air from the indoor side.
• Clean the trap: If there is a P-trap, remove and clean it thoroughly. Reinstall with proper slope.
• Flush with cleaning solution: Pour a mixture of warm water and a small amount of vinegar or approved coil cleaner into the drain pan to help dissolve buildup.
• Inspect drain pan: Use a flashlight to check for cracks or rust holes in the primary pan. If damaged, the pan or coil assembly may need replacement.