If you’ve been running your central air conditioner and have puddles under your furnace or air handler, don’t panic. No, you don’t have some strange plumbing leak that’s getting into your heating and air conditioning system – you probably just have a plugged condensate drain line.
Your central air conditioning system or heat pump not only cools the air inside your home, it also dehumidifies the air which helps your home feel cooler and more comfortable. Moisture is extracted from the air as it passes over the evaporator coil located in chamber above your furnace or in the air handler of your heat pump.
Moisture (called condensate) condenses and collects on the evaporator coil and drips into a collection pan below. The pan drains out through a condensate drain line which is typically made of PVC pipe. In some installations, the drain line is routed directly outside or to a drain. In other cases, the drain line goes to a small sump pump that pumps the water outside or to a drain through a clear plastic hose.
The condensate drain line can sometimes become clogged with dust or mold and mildew growth. When that happens the condensate will back up and drip out onto your floor.
It is usually pretty easy to clear a clogged condensate line. If you are fortunate enough to have an air compressor, a blast of air will usually do the trick. Sometimes you can suck the clog out from the end using a wet/dry vac. Otherwise, running a small plumbing snake or even a wire coat hanger through the condensate drain line will clear the clog. Once you have the clog cleared, you can help prevent new clogs from forming by mixing a cup of bleach with a gallon of warm water and pouring through the condensate drain line twice a year. Be very careful and take all necessary safety precautions when handling bleach.
