Abstract: A combustion control system applicable universally to various types of combustion apparatus operating with different control timing and different fuel is disclosed. The combustion control system includes a data selector circuit, a control circuit, and a control timer circuit using a counter as timing means. The data selector circuit includes a circuit section for providing pre-purge timing and another circuit section for providing ignition timing as required. The control circuit includes an R-S flip-flop controlled by the pre-purge timing produced by the data selector circuit section.