A Water Leak in an A/C

Slope

• This problem only occurs with window or wall-mounted air conditioning units. When the unit tilts toward the interior of the room, excess water from the condensate drain leaks down the wall or onto the floor, according to the website LG Knowledge Base. Air conditioning units come with a small bracket that helps keep the unit level by supporting it properly on both sides of the window. When this bracket breaks or the unit is installed improperly, water drains inside the house instead of outside.

Drain Problems

• As the air conditioner removes moisture from the air, it condenses and flows down to a drain pan. A condensate pump or floor drain allows this to travel out of the home without causing problems, according to Air Comfort Systems. When the condensate pump breaks, water builds up until it overflows. A blockage in the floor drain also allows this to happen. Debris accumulating in the drain pan takes up the space that the water needs. Drain pans are designed to hold plenty of water, but when full of debris they become overfilled on days with high humidity.

Holes in Coil

• The condenser coils attract the moisture in the air and give it a surface to condense on. The drain pan is situated below these coils and will leak water around the air conditioning unit if it has a hole from rust or damage in it, according to G&S Mechanical Services. Look for an isolated leak to determine whether a hole is causing the problem rather than an overflowing drain pan. Replacing the drain pan or patching the hole fixes the problem.

Dirty Coils

• Heavy coatings of dust, grime or oil on the condenser coil prevents water from condensing properly. Instead of gathering in the drain, it drips back off into the rest of the unit and leaks out in random areas, according to G&S Mechanical Services. Grease and oil often get onto the coil during repairs when motors and other parts are oiled. A broken part spraying out lubricant will also interfere with the proper condensation and draining process.