Air Conditioner Drain Line 101

Why does my AC have a drain line? 

When your air conditioner (AC) is running, condensation forms on the evaporator coil inside your air handler, which drips into a pan beneath the coil. That water should travel from the pan to outside your home via a condensation drain line.

What causes the drain line to become clogged?

Inside the drain pan on its way through the drain line, the water will pick up dirt, dust, and even pet hair. This will in turn cause mildew and algae to grow in your drain line.  All of this can cause the drain line to become backed up and eventually the pan will overflow.

If your system was installed within the last couple of years and by a professional installer, your drain system should have a safety switch installed that will shut the system down if the drain becomes backed up. This way you don’t end up with an overflow in your attic, closet, or wherever your air handler is located.  If you do not have a safety switch for your drain, one can be added.

Is blowing out your HVAC drain line enough?

If you are just blowing out the lines, the algae and mildew are still left behind. If you are doing the cleaning yourself, we recommend using vinegar and hot water or even a HVAC approved cleaner that will dissolve the slime buildup.

Our service technicians use a product that contains digestive enzymes that break up and disperse the slime, sludge, and sediment that tends to gum up the pan, p-trap, and piping.  We then add a gel strip to the pan that lasts for up to 6 months. These strips prevent sludge build up and drain pan corrosion, as well as control odors. The strips will dissolve and are safe for metal and plastic drain pans.