Outside vents or chimneys should not be used except for large industrial installations. A vent connector shall not be connected to a chimney serving a fireplace, unless the fireplace opening is permanently sealed and the fireplace discontinued for use.
NOTE: An automatically controlled gas appliance connected to a chimney, which also services equipment for the combustion of gas or liquid fuel shall be equipped with a safety shut-off device. If two or more openings are provided into one chimney, they shall be at different levels.
