Abstract: Evaporative cooler apparatus includes two pumps, a primary pump which pumps water to an evaporative medium and a secondary pump for pumping water from the bottom of the cooler to drain the water reservoir of the cooler. The secondary, or drain pump includes a programmable timer that is operable by a user to select a run time duration for the pump motor from a plurality of possible run times. The programmable drain pump also includes a user control for selection of an off-state time from a plurality of available off-state times or intervals between run times of the drain pump motor. The programmable drain pump also includes a constant on control and a test control.