In this subtitle the following words have the meanings indicated. “Carbon monoxide alarm” means a device that: senses carbon monoxide; when sensing carbon monoxide, is capable of emitting a distinct and audible sound; is listed and carries the listing of a nationally recognized testing laboratory approved by the Office of the State Fire Marshal; and is wired into an alternating current (AC) powerline with secondary battery backup; or for a hotel, a lodging or rooming house, or a rental dwelling unit: is wired into an alternating current (AC) powerline with secondary battery backup; is battery–powered, sealed, tamper resistant, and using a long–life battery that has a life of not less than 10 years; or is connected to an on–site control unit that monitors the carbon monoxide alarm remotely so that a responsible party is alerted when the device activates the alarm signal and receives its primary power from a battery or the control unit. “Dwelling” means a building or part of a building that provides living or sleeping facilities for one or more individuals. “Dwelling” includes a one or two family dwelling, multifamily dwelling, hotel, lodging or rooming house, or dormitory. “Hotel” has the meaning stated in § 9–201 of this article. “Install” means to attach to the wall or ceiling of a dwelling in accordance with: the National Fire Protection Association (NFPA) 720 standard for the installation of carbon monoxide warning equipment in dwelling units; and the manufacturer’s recommendations. “Lodging or rooming house” has the meaning stated in § 9–201 of this article. “Rental dwelling unit” has the meaning stated in § 6–801 of the Environment Article. “Sleeping area” has the meaning stated in § 9–101 of this article.

This subtitle only applies to: a dwelling that: relies on the combustion of a fossil fuel for heat, ventilation, hot water, or clothes dryer operation; and is a newly constructed dwelling for which a building permit is issued on or after January 1, 2008; or a hotel, a lodging or rooming house, or a rental dwelling unit.

A carbon monoxide alarm may be combined with a smoke alarm if the combined device complies with: this subtitle; Title 9 of this article; and American National Standards Institute (ANSI)/Underwriters Laboratories (UL) standards 217 and 2034 or ANSI/UL 268 and 2075.

Except as provided in subsections (b) and (c) of this section, there must be a carbon monoxide alarm installed in a central location outside of each sleeping area within a dwelling subject to this subtitle. For a hotel or a lodging or rooming house, on or after April 1, 2017, there must be a carbon monoxide alarm installed within the dwelling, as follows: on the wall inside each guest room that: contains a device that emits carbon monoxide; is adjacent to a room or area that contains a device that emits carbon monoxide; is adjacent to an enclosed unventilated attached garage; or is connected by ductwork to an enclosed unventilated attached garage or room or area that contains a device that emits carbon monoxide; and on a wall in each room or area that: contains a device that emits carbon monoxide; is adjacent to a room or area that contains a device that emits carbon monoxide; or is adjacent to an enclosed unventilated attached garage. For a rental dwelling unit, on or after April 1, 2018, there must be a carbon monoxide alarm installed within the dwelling as follows: outside and in the immediate vicinity of each separate sleeping area; and on every level of the unit, including the basement. Notwithstanding subsections (a), (b), and (c) of this section, if there is a centralized alarm system that is capable of emitting a distinct and audible sound to warn all occupants, the owner of a dwelling may install a carbon monoxide alarm within 25 feet of any carbon monoxide–producing fixture and equipment.

Except as part of routine maintenance, a person may not render a carbon monoxide alarm inoperable.

This subtitle does not prevent a county or municipal corporation from enacting more stringent laws that relate to carbon monoxide alarms.