A fuel-fired appliance must not obtain combustion air from which of the following locations?

Fuel-fired appliances require a specific amount and quality of combustion air for safe and efficient operation. When combustion air is obtained from areas such as living rooms, bathrooms, or storage closets, there can be significant risks associated with air quality and appliance performance.

Living rooms are generally used for gatherings and activities, and introducing combustion air from that space could lead to the displacement of oxygen and the possible introduction of combustion byproducts into the living space. This creates a potential health hazard for the occupants.

Bathrooms typically have limited air flow and are often used for personal hygiene where maintaining a clean air quality is essential. Drawing combustion air from a bathroom can also introduce moisture and contaminants that can adversely affect combustion efficiency and could lead to conditions such as rusting within the appliance.

Storage closets often contain materials and chemicals that could be harmful if they were to enter the combustion process. Using air from these areas can create a risk of flammable vapors, which can pose a serious safety hazard.

In summary, ensuring that fuel-fired appliances obtain combustion air from appropriately designated and safe areas is critical to prevent safety hazards and maintain optimal appliance performance. Thus, the statement that these appliances must not obtain combustion air from living rooms, bathrooms, or storage closets is vital, making "all of the