This is for natural gas applications only. Remove the 5 pin plug on the unit and connect the blue wire to the "com" connection and the white wire to the "l" connection. The replacement will need to be bushed from ¾" npt to ½" npt on both the in as well as the out ports. It will also need to be adjusted from 3.5 to 3.3" w.c. - there is no replacement for lp applications.