A solid fuel-burning appliance or fireplace shall not connect to a chimney passageway venting another __________.

A solid fuel-burning appliance or fireplace must have its own dedicated chimney passageway because connecting it to a chimney venting another appliance can create several significant safety hazards. The primary concern is that the combustion gases produced by one appliance can potentially backdraft into another, leading to dangerous situations such as carbon monoxide poisoning. Furthermore, each appliance has specific venting requirements based on its size, fuel type, and design; combining them could lead to inadequate venting performance and possibly a fire hazard. Therefore, ensuring that a solid fuel-burning appliance connects to a separate chimney passageway promotes safe and efficient operation, adhering to established mechanical codes.