The Fenwal 35-605606-227 24Vdsi is a complex ignition control module intended for use in HVAC and air conditioning systems. This part is essential to starting the combustion process inside the system. It has a 30-second pre-purge interval to guarantee a clean ignition environment and a 15-second ignition trial to safely establish the flame. It operates at 24-volt direct spark ignition... https://www.partshnc.com/35-605606-227-fenwal-24vdsi30secpp-15sectfi3trys