Step 7 · Inspect and Clear Condensate Drain Line

The condensate drain line is typically a PVC pipe connected to the indoor air handler that carries away moisture removed from the air. Locate the end of the drain line, usually outside your home or near the indoor unit. Check for any visible obstructions or standing water. You can use a wet/dry vacuum to suck out any debris from the end of the line, or pour a mixture of water and vinegar (about 1 cup of vinegar to 1 gallon of water) down the line to help clear algae and buildup. Be sure to check the drain pan beneath the evaporator coil for standing water, which indicates a blockage.