Heating equipment differs in design and purpose. Consequently, clearances or distance from flammables recommended by N.F.P.A. vary. Generally, single-walled stoves which produce radiant heat should be spaced at least three feet from combustible surfaces and stove pipe connectors should be at least 18 inches away. A circulating stove is manufactured with a surrounding shield which controls the flow of heat away from the firebox. These shielded stoves can be placed nearer to combustible walls.
Manufacturers usually recommend an adequate clearance.
You may provide your own wall shielding by screening the combustible surface with non-combustible barriers such as sheet metal, asbestos board, brick or tile. An air space of at least an inch but preferably two inches should be left between the wall and the shield. Air currents will carry away the heat transmitted through the steel. A brick or stove wall built directly against a combustible wall is false security and sometimes worse than no shield at all. A masonry hearth, a thick layer of sand or gravel, or a mat of asbestos sandwiched between layers of sheet metal should be beneath the stove.