How to Contend with Mold Growth in the Drip Pan

Published on: August 16, 2012

Central air conditioning units may be breeding grounds for mold and mildew. Because central air conditioners not only cool the home, but they also act as dehumidifiers by removing moisture from the air. In fact, removal of moisture from the air is, in part, how central air conditioners work to keep the air inside the home cool and comfortable during the summer season. When moisture is removed from the air, the less humid air feels cooler and more comfortable.

As central air conditioning units remove moisture from the air, the moisture is collected into condensate trays and drip pans. Standing moisture presents an optimal environment for the growth of mold and mildew. Add in the dust that may accumulate in and around the vents and ducts, and a mold problem may develop. If you notice mold in the drip pan of your air conditioning unit, chances are that you need the HVAC system inspected by an AC repair technician for the presence of mold in the coils and other components of the unit.

If you spot mold growth in the drip pan of your air conditioner unit, you likely have a mold issue that you cannot see. Dust in the air, combined with moisture that is removed from the air by the AC system, may create a mold issue. Mold growth in the drip pan may be just one symptom of mold infestation inside your AC unit and ductwork. However, if you find mold growth in the drip pan, you should perform some immediate steps to clean the mold and prevent the further development of mold in the pan.

1.) Empty the water from the drip pan.

The first task if you find mold in the drip pan is to empty any standing water from the pan. If mold has clogged the drain, the water may have filled the drip pan and run over onto the ceiling, floor or wall. Clean the area of all water and dry the area. You may need to use a fan or dryer to make sure the area is dry.

2.) Check the drain and drain lines of the drip pan for clogs or damage. Unclog or repair the drain lines.

If the drain lines are clogged or damaged, this will prevent the water from draining from the condensate tray or drip pan. If the water is not draining properly from the drip pan or tray, the presence of moisture, combined with dust and dirt from the AC system, is a prime environment for mold growth. The key to stopping mold growth is to ensure that water is properly draining from the drip pan or tray. Call an AC repair company to check and repair your drain lines, if needed. However, many homeowners choose to repair or replace the drain lines themselves as this repair is generally a small project.

If the line is clogged, you may attempt to unclog a drain line before calling an AC repair company. To clean mold or debris from the drain line, use a wet/dry vacuum to suck the mold or debris out of the line. However, if you prefer not to attempt the task, unclogging or replacing a drip pan or condensate tray drain line is an inexpensive AC repair. In fact, if you have an annual preventative maintenance check, the drain line unclogging or repair may be included in your air conditioning maintenance visit.

3.) Schedule an air conditioning maintenance visit with your HVAC company to have the AC coils and components cleaned and checked for mold. If mold is growing in the drip pan, you may have mold issues with other components of the AC unit. An air conditioning maintenance technician will check the system for mold and clean any mold that is not readily visible.

Minimize the Possibility of Mold Growth

In addition to regular air conditioning maintenance, there are a few steps you can take to minimize the possibility of mold growth in and around the AC system.

1.) Clean your home regularly to reduce the presence of dust in the home.

Dust, when combined with moisture, promotes the growth of mold and mildew. Regular cleaning and dusting of the home will reduce the chances that mold develops in the AC system and ductwork.

2.) Flush the drip pan drain line once every six months.

Remove the cap from the drain pipe and pour about one quarter of a cup of bleach or vinegar down into the pipe. Let the bleach or vinegar sit in the pipe for about 30 minutes. This will allow the bleach or vinegar to kill any mold, mildew or bacteria inside the drain pipe. After 20 minutes, pour about a gallon of warm water into the pipe to wash the bleach or vinegar out of the pipe. Check the outside drain line to ensure the water has passed through the pipe and out of the home. If you are not sure about the location of the drain pipe cap, or if you need assistance with flushing the drip pan drain, call an AC repair technician or check the owners manual for your unit.

3.) Be sure to change or clean your AC filter once per month. Dust and debris build-up in the AC filter will contribute to the growth of mold and mildew in the home.

4.) Be sure to have an annual air conditioning maintenance tune-up performed once per year.