The National Building Code requires installation of a CO detector/alarm in the service room / furnace room / boiler room of a multi-unit residential facility.

However when I review the installation manual of some of the standard CSA / ULC listed CO detectors such as BRK and Kiddie, they mention not to install the CO detectors in furnace room.

I wanted to inquire if there are any manufacturers producing CO detectors compatible for installation in furnace room / boiler room? If not, then what type of clearances should be maintained from furnaces / boilers so CO detectors could be installed in furnace rooms?

Thank you.