The invention is directed to a chlorinator mounted inline in a water purification system having a housing having an inlet end and an outlet end and an upper compartment having an electronics section with a controller unit contained within the electronics section and in electrical communication with a power source and an at least one electrolytic plate. The system having a heat sink member in thermal communication with the controller, wherein the flow of the water in the water purification system cools the heat sink member and the controller unit.