Every year we receive calls from frantic homeowners stating that there is water leaking from the air conditioner coil on top of the furnace. Since your homes central air conditioner does not use water to cool the home, where does this water come from? And why is it leaking?
Split-system AC units produce condensation moisture on the indoor evaporator coil while removing humidity from inside the home. This moisture runs down the coil and into a drain pan located below the coil, where it is then diverted out to a drain (normally a floor drain, or into a condensate pump if no floor drain is available).
If water is leaking out from the edges of the coil, and onto and down the side of the furnace and onto the floor, chances are you have a plugged drain opening that is causing the drain pan to overflow. Its also possible that your drain pan is cracked, or in the cases of older coils, rusted through. But well over 95% of these type of situations is merely a plugged condensate drain, and easily corrected.
If you see water leaking out from your indoor AC coil, it is very important to have this repaired immediately, as not only can the leaking water cause damage to the homes floor, carpet, etc, but water leaking into the furnace can result in damaged components and expensive repairs. Turn off your AC unit immediately if you notice a leak from the coil, and call us to have the problem corrected.
In most cases this is just a minor problem and easily corrected. But if left alone, it can result in expensive repairs.