While most newer units have either a drain plug or pan, some units do not have any type of manual drainage system. In these cases take the unit out of the window, and set it upside down with the front of the unit facing upward. After a few minutes, the liquid will drain from the unit. To avoid flooding your room, make sure that the air conditioner is tilted backward in the window, allowing any excess water to exit through the back of the unit. If your unit has a drainage pan or plug, check it periodically and manually empty the pan, which is especially important after a heavy rain to help the unit to remain functional.
Many homes do not have a central air conditioning system that will automatically drain condensation or rainwater from the system. Those who own "room" or "window" air conditioning units must know how to properly drain them to avoid flooding the room and keeping the unit in a safe operating condition. Locating the drain on these window units can be difficult sometimes, but by finding the drain location and knowing the method of drainage, you can easily remove excess liquids from the unit.
Unplug the air conditioner from the wall. Given that you will be touching the unit and effectively looking for water, it is best to remove any possibility of electric shock.
Take the unit out of the window. This step is optional, but it is recommended because it will make the process of finding the drain much simpler.
Look for a pull-out pan. Most newer air conditioners will have a pan that you can pull out of the unit and empty, which is called the evaporator drain pan. It catches all the condensation that forms inside of the unit. If your unit does not have an evaporator drain pan, proceed to step 4.
Look for a small rubber plug. Depending on the manufacturer of your unit, it could be located in a variety of places, including the lower corners on the back or near the back on the underside of the unit. It is generally a slightly different color than the unit itself and is approximately 1-inch in diameter.
Pull this plug to empty any water that may have collected in the unit.