Abstract: A foamer pump for dispensing foam has a simple construction and utilizes a single piston to reduce the volume of both a fluid chamber and an air chamber. A portion of the actuating mechanism helps to unseat a check valve at the outlet of the fluid chamber. The foamer pump has a fluid chamber, and an outlet of the fluid chamber is connected to a mixing chamber. An air chamber has an air channel that connects the air chamber to ambient air in a first position and to the mixing chamber in a second position. A piston causes the volume of the air chamber and the liquid chamber each to be reduced, forcing air from the air chamber and foamable fluid from the liquid chamber into the mixing chamber where they blend to form an air/liquid mixture.