DIY: Condensate Drain Line Maintenance

Water gushing down your ceiling is not a sight any homeowner wants to come home to, yet it is all too common when air conditioning system drain lines get clogged and overflow. Because the weather in Houston is both hot and humid, it is very easy for these condensate drain lines to collect a slimy mixture of dust, mold, and algae. Yuck! Luckily, there are several ways you can keep your air conditioner’s drain line clear. If you can measure out liquid and pour it in a pipe, you have the necessary skills to keep your drain line unclogged year round.

What chemical should I pour down the condensate drain?

We recommend at least four times a year to pour a one-fourth to one-half cup of plain, white vinegar in your condensate drain. Don’t use bleach as it can spill onto your metal drain pan and react with the metal, causing problems later on. Vinegar is acidic but does not react with copper, zinc, or aluminum so there is no risk of spilling or accidentally harming other metal pipes and equipment nearby.

pouring vinegar into drain Where is the drain line located?

For many homes in the Gulf Coast, the central air conditioner’s evaporator coil and furnace are located in the attic. The evaporator coil is encased in a box with a drain sitting underneath and hoses surrounding it. You’ll want to look for 3/4″ PVC pipe that is open to the air. This is where you want to pour that vinegar.

How else can I protect my ceiling/wall from leaks?

If you do not already have one, your HVAC contractor can install a “ceiling saver” or “float switch.”  These handy devices turn off the air conditioning unit if the drain pan fills up, which only  happens when the drain line is stopped up. This will keep your air conditioner from pumping out more water into the pan, eliminating costly spills and sheetrock to be replaced.

Can UV lights in the evaporator coil reduce the slime?

Yes. Another tactic we recommend is installing an Ultraviolet Light in the evaporator coil. Not only does this improve air quality in the home, it reduces the grime that can develop on the evaporator coil and slime that can accumulate in the condensate drain line, too. Because our climate is so humid, the air conditioning equipment parts that take out humidity from the air are constantly wet and that is a recipe for a build up of dust, mold, and algae. By the way, Terry’s A/C and Heating periodically runs specials in the summer on installing UV lights.

What do I do if I see my drain pan full of water?

Good news. You’ve caught the problem early and can call your HVAC contractor for help. A reputable contractor will blow out the line and do a thorough check to make sure that the problem isn’t coming back. By keeping your line maintained with regular doses of vinegar, once each season, this problem should be less common.

We Can Help

If you are in need of expert advice on maintaining and repairing your air conditioning system, contact the cooling experts at Terry’s A/C and Heating at 281-495-7830 and see our service area. We’ve seen all sorts of condensate drain issues from misdiagnosed plumbing problems to critters in the attic chewing through drain lines to get to the water, we can help keep your HVAC system running when the heat is on. Find out how we are different from other contractors in West Houston and give us a call today!