Hot surface ignition system

A hot-surface ignition (HSI) system that controls the operation of industrial gas-fired appliances with levels of safety, reliability, and versatility never before achieved is presented. A microcomputer-based control module provides multilevel component fault tolerance in critical areas such as the flame-sensing and valve-control circuits. The program in the control module negates unsafe operation in the event of a failure of the microcomputer by requiring diverse signals to exist at precise time relationships to execute particular functions. The control module is designed for reliable operation far beyond normal appliance life