Abstract: A water purification device comprises a unitized self regulating water distillation unit for processing drinking water. The distillation system is simple, rugged, and inexpensive to install, operate, and maintain. Two internal float switches in combination with an in-line, normally closed water supply valve and with an internal and always submerged heating element that are controlled by an electrical circuit including two electrical relays that when effectively combined enable water to be distilled through an air-cooled condensing coil housed in a compact unitized body. A mechanical insulation barrier is also provided, insulating the exterior of the device from the heat of the distillation process as well as internally directing the heat generated by the distillation process so that may be exhausted. Water may therefore be processed easily and routinely on a daily basis with a minimal amount of effort, cost, and maintenance by the owner or owners of such a system.