Direct hot surface pilot ignition, 1/2 X 1/2-inch National Pipe Thread (NPT). SmartValve™ system controls combine gas flow control and electronic intermittent pilot sequencing functions into single unit and provide all gas ignition safety functions by controlling gas flow, ignition source and air blower. These controls communicate directly with electronic fan timer (ST9160 electronic fan timer for single stage applications; ST9162 electronic fan timer for two-stage applications) in typical forced warm air furnace applications. They also interface with 208907 terminal board, providing compatibility with power-stealing thermostats. Or they directly interface with appropriate power supplies and system thermostat for additional appliance applications. When controlled directly by thermostat, these controls do not provide post-purge function, because power to control is removed when thermostat call for heat ends. SV9541 systems are suitable for wide range of fan-assisted combustion gas-fired appliances including furnaces, rooftop furnaces, boilers, unit heaters, infrared heaters, water heaters and commercial cooking appliances.