The Chief Fire Official has the authority to enforce the Fire Code within his or her jurisdiction and should be contacted prior to implementing any opinion expressed in the following information. Proper placement of a CO alarm is important. The CO alarm must be located adjacent to all sleeping areas of the home to increase the likelihood that sleeping occupants will hear the alarm if it goes off. Unlike smoke, which rises to the ceiling, CO mixes with air. Hence CO alarms may be installed at any height. However, if a combination smoke/CO alarm is used, it must be installed on or near the ceiling as per manufacturer's instructions, to ensure that it can detect smoke effectively.
Existing residential occupancies that contain at least one fuel-burning appliance (e.g., gas water heater or gas furnace), fireplace or an attached garage, require the installation of a CO alarm.(Ontario). Check this article which says most of the fatal poisoning in Canada is CO poisoning Why Do You Need A CO Detector In Your Home? | Calgary Alarm Inc.. It also says that they need to be placed near bedrooms where they can be heard.
Of course.