I have a question on clearances listed on stoves. What I have now in my basment is a 2005 forced hot air Natural gas furnace that has PVC intake and exhaust. On the right side of the furnace, I have a Hot Blast wood and coal add on furnace connected to the older chimney with a 6" stainless steal hard piped liner with clean out door. ( not the cheaper flex liner) When I had the Hot blast instaled the inspector said it had to be 6" away form each other. ( Hot Blast listed clearance to combustables 6") Now I would like to remove the Hot Blast furnace and put a pellet stove in place of it, but the listed clearances for most bigger pellet stoves that are 50,000 btu are 12" and up form combustables. I would not be able to move the newer stove over a foot because it will then be in the way of the walking path to my electric panel and Hatch way door. My question is, A metal cased Natural gas furnace, Is this legaly considered as a combustable surface? My furnace tech dose not belive that the Gas furnace is considered as a combustable because it has a incased burn camber then insulation an outer metal casing.