What willieG is saying is true, as an owner we may choose to take a risk in exchange for the benefit. Then we need to take responsibility. But as an installer we try to make sure we don't take on undue liability. I hesitate to do any maintenance and repair to any outdoor furnace inside a building as any accident may be placed back on the last person that indicated the furnace was in operational condition. And never install a unit inside a building. A sale is not worth the risk to me. I have been asked by an insurance company more than once what was the cause of the fire. Don't ask me to lie. But if you want the building , take the responsibility for safe operation, liability for accidents and assume their could be a malfunction in the stove itself. I have went back to a costumer and found a building with stove, chainsaws, gas, tools, lawnmowers and even tractor and farm equipment in the same building. More risk than I want to be close to.