Cleaning the A/C condensate drain can range from simple maintenance to an urgent emergency service call if the system clogs and overflows. As long as the condensate drain system is flowing freely, it all goes through a drain line to an outdoor discharge point or into a connection with the household sanitary sewer.

When blockages occur, however, an overflowing condensate drain pan can rapidly cause serious consequences in your building. Depending on the location of the air handler, you could experience water damage, a ceiling cave-in, mold growth or ruined HVAC equipment.

What You Can Do

DIY steps for cleaning the A/C condensate drain system are limited mainly to a preventive procedure.

1. Most condensate drain lines are PVC pipe. Near the connection to the condensate drain pan, locate the U-shaped trap inserted in the span of drain line. A short pipe with a threaded clean-out cap normally extends upwards from the trap.
2. Unscrew the clean-out cap and insert a funnel. Pour a cup of white distilled vinegar into the drain line.
3. Allow the solution to remain in the line for 30 minutes, then flush the line with water.