<Dd> 2 . Detectors must be on the ceiling in the same room as permanently installed fuel - burning appliances, and </Dd> <Dd> 3 . Detectors must be located on every habitable level and in every HVAC zone of the building . </Dd> <P> Gas organizations will often recommend to get gas appliances serviced at least once a year . </P> <P> The NFPA standard is not necessarily enforced by law . As of April 2006, the U.S. state of Massachusetts requires detectors to be present in all residences with potential CO sources, regardless of building age and whether they are owner - occupied or rented . This is enforced by municipal inspectors, and was inspired by the death of 7 - year - old Nicole Garofalo in 2005 due to snow blocking a home heating vent . Other jurisdictions may have no requirement or only mandate detectors for new construction or at time of sale . </P>

What happens when you die from.carbon monoxide poisoning