Door insulation 31183 on the front door with hole for the burner Used on the Clean Burn model CB 2500, CB 1500, CB 1750 and CB 3250 waste oil furnace. You may have another variation of these models such as 1501, 1502 or 2501. This board will also work with those variations. If you have any questions please give us a call (765) 449-0113 or (800) 765-3345.