DINOSAUR ELECTRONICS - The FAN 50 Plus Pins is designed to replace the new Suburban« Fan Control boards and the Atwood« / HydroFlame« Fan Control boards as well as the Dinosaur Fan Control boards which have been available since 1994. This board can also be used to upgrade older furnaces to add the Fan Control feature.The basic purpose of a Fan Control Ignitor Board is to shut the fan motor off if the board fails to sense a flame after the third ignition try. Thus, battery drain is reduced and the needless blowing of cold air is eliminated. The FAN 50 Plus Pins, after shutting the fan motor off, will wait for 1 hour and repeat the whole sequence again before permanent shut down. For 12V DC Furnaces ONLY! The ôFan Controlö feature MUST BE USED for proper operation of this board. Features: ò Jumper selectable operation. ò Works in 12V DC furnaces*. ò Microcontrolled. ò 3.35" x 4.25". ò Diagnostic LED. *Note: Fan control boards should not be used in DuoTherm« 900 series furnaces that have the thermostat in the ground circuit. Ignitor Board, Fan 50 Plus Pins.