Blocked condensation drain lines often cause excessive amounts of water in an air conditioner drain pan. These lines are designed to funnel excess water from condensation away from the air conditioning system inside the home. If these lines become blocked, the excess water drains into a drain pan.
The water created by an air conditioning system is caused by condensation. Condensation occurs as air from inside the house is cooled by being blown across the evaporator coil. This condensation is then funneled outside of the house via a drain line. A drain pan is placed below the air conditioning system inside the house in case the drain line becomes clogged and the water has no way to escape.
The process of cleaning the primary condensation drain line varies depending on the model of air conditioner. Traditionally, the drain line is located near the air unit and is either open or has a cap. If there is a cap, it's easily removed so the homeowner can check that the water caused by condensation is flowing freely away from the air unit. If it isn't, most clogs may be removed by pouring a mixture of bleach and warm water down the drain line.