There are a few simple and easy steps any homeowner can perform on their heating and cooling system that can help keep their equipment operating at peak performance. Last month I went over the importance of keeping a proper sized, clean filter in the air handler/furnace. This month we will go over one of the most overlooked parts of your air conditioning system, the condensate drain. The condensate drain system is one of those things that is out of sight out of mind until it fails and overflows potentially causing thousands of dollars of damage to your home and furnishings. With just a few simple steps this flooding and damage can be avoided.
First, it is important you understand what your condensate drain is. There is moisture in the form of humidity suspended in the air in your home and before your air conditioner can cool the air it has to remove the moisture. Water is removed from the air by a part of your cooling system called the evaporator coil. The coil sits in a large collection drain pan on top of or connected to the end of the furnace/air handler. The water sits in the drain pan until there is enough to flow into a white 3/4″ PVC drain line at which time it flows either into a gravity fed drain system and out the wall of your home or a small collection pump which pumps the water out your home in a small clear vinyl tube. The amount of water removed by your air conditioner in the summer can be staggering. Gallons of water are removed every summer day and if you do not keep this part of your air conditioner maintained, it will fail causing damage to your home. Most homeowners I meet with have owned a home sometime in their life that had a water leak from a clogged or inoperative condensate drain.
Locating your homes condensate drain should not be difficult. If your furnace/air handler is a upright type, the condensate drain line ties into the cooling coil right above the top of the furnace and it is a white plastic PVC pipe 3/4″ in diameter. If you furnace/air handler lays down in an attic or crawl space the drain line ties into the cooling coil about six or seven inches off the ground and is also almost always 3/4″ white PVC pipe also. The drain system is what we call a gravity drain which means the water flows slowly and is pushed out from the pressure of the standing falling water. The water removed from your air in your home gets mixed with the airborne dirt and it clogs up the drain line. Molds and algae grow in the drain pan and drain line and cause the water to back up and overflow onto the ceiling of an attic system or the carpet and flooring of an upright system in a basement or closet. Even a crawl space furnace/air handler condensate leak can cause trouble by often causing premature rusting of the furnace/air handler cabinet or coil cabinet.
There are a couple of ways of cleaning out the drain line and all can be performed by a homeowner with a few inexpensive supplies. The first thing you need to do is locate your drain line and look for a clean-out "tee". The clean-out "tee" is a 3/4″ PVC plastic "T" shaped fitting right off your cooling coil. Sometimes it has a cap on it and sometimes it is just open to the drain. Put a funnel in the "T" and pour a quart or two of bleach into the drain. Go slowly as to allow the bleach to kill the mold and mildew . This should be done once a year at least. If your drain line is especially dirty and it has not been cleaned recently, you might want to take a garden hose and blow it out slowly with a little water pressure, or use a tank of compressed air to blow the crud out. If you have a condensate pump, the bleach will fill up the water reservoir and turn on the pump cleaning out the vinyl exit tubing.
If you do not have a clean out "T" on your system, it is very easy to add one. Go to your home improvement store and purchase a 3/4″ PVC "T" and a can of PVC glue. Cut the drain line with a hacksaw near the coil and glue in the "T" with the opening facing up.
For those of you with an attic system, there is another drain system to be aware of and that is the secondary drain pan and line. The secondary drain pan and line is there to catch any water that leaks from the primary drain system we have been discussing. The secondary pan is the pan that the furnace or coil sits in and it looks like a big cake pan with a drain line coming off it. Often times there is a float switch attached to it with wires and the job of the switch is to cut off your air conditioner before water damage can occur. Check this pan and make sure there is no water in it or no evidence of mineral deposits where water has dried and evaporated. If there is any evidence of water in your secondary pan you need to make sure that the problem is corrected by yourself or by a professional as the standing water will damage the bottom of the furnace cabinet..
With just a small amount of time and preparation, you can be assured that your condensate drain will flow freely all summer long and you will no longer have to worry about water stains or damage.