Suburban Furnace NT-40 Core (2614A) CORE ONLY 2051A This is the core for a Suburban NT-40 furnace. It does not come with the exterior jacket. Compatibility: Suburban NT-40 Furnace BTU Level: 40000 BTU Width: 12 Inch Depth: 23 Inch Height: 12-1/2 Inch With Electronic Ignition... See More