The FAN 50 Plus Pins is designed to replace the new Suburban® and Atwood® / HydroFlame® Fan Control boards as well as maintain backward compatibility with the Fan 50 Plus, and UIB 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.