According to Section 504.1, when is a fuel-burning water heater permitted to be installed in a bedroom closet without being a direct-vent type?

• If the closet has a listed, gasketed door with a self-closing device, obtains combustion air from outdoors, and is for the water heater's exclusive use.
• If the water heater is electric and listed per UL 174.
• Only if the closet has a standard interior door and a louver for ventilation.
• It is never permitted; all bedroom installations must be direct-vent.