Robertshaw 780-735 Lockout Spark Ignition Module. The 780 Series Ignition Modules are specifically designed for use on heating systems that utilize fired gas. This Ignitor is designed to read and act according to the demand for heat by the thermostat. This Robertshaw 780-735 Lockout Spark Ignition Module has a 60 second head lockout feature, and a time delay. This 780-735 Lockout Spark Ignition Module provides lockout and complete gas shutoff if ignition is not detected after the ignition sequences have been completed. This Lockout Ignitor also functions as a replacement part, and is designed to function and perform in most residential applications.