The Ontario Building Code | Chimney Flue Limitations
9.21.2.1. Chimney Flue Limitations
(1) Achimney flue that serves a fireplace or incinerator shall not serve any other appliance.
(2) Achimney flue that serves a solid fuel-burning appliance shall not be connected to a natural gas- or propane-fired appliance.
(3) Achimney flue that serves a solid fuel-burning appliance shall not be connected to an oil-burning appliance unless the solid fuel-burning appliance is listed for such installation and the installation of both appliances meets their respective installation requirements.