CO Alarms




This Spring has brought significant changes to not only the smoke alarm law, but the requirements for carbon monoxide alarms.  Considering that the sufficiency of these alarms are addressed in a home inspection and in the State Residential Property Disclosure Statement, is it critical to understand your responsibility as a homeowner, landlord, or Realtor advising clients.  Read below to ensure your compliance with the new law effective April 1, 2018 and the additional measures you can take to reduce the risk of injury or death caused by carbon monoxide.

Does the new carbon monoxide alarm law apply to me or my client?

Answer these questions:

Does the dwelling at issue:

  1. Have equipment that can emit carbon monoxide (CO)?
    1. including gas appliances (furnace, hot water heater, dryer, fireplace, stove, cooktop, etc.) and/or
    2. fuel-burning equipment (oil burner furnace / boiler unit etc.) and/or
    3. fireplaces, woodstoves, etc. that use hardwood, pellets, coal, etc.
  2. Have an enclosed attached garage, but otherwise is powered solely by an electric power supply?

If you answered “yes” to either of these questions, continue with this question:

  1. Is the dwelling:
    1. a residential dwelling built on or after January 1, 2008
    2. a rental dwelling unit? (“Rental dwelling unit” is defined as “a room or group of rooms that form a single independent habitable rental unit for permanent occupation by one or more individuals that has living facilities with permanent provisions for living, sleeping, eating, cooking, and sanitation.” Code. Ann., Public Safety Sec. 12-1101(g).
    3. a hotel or a lodging or rooming house? (See Code. Ann., Public Safety Sec. 9-201.

If you answered “yes” to 3a, 3b, or 3c above, the dwelling comes within the scope of the new law. 

If you are exempt from the Law and have:

1) an enclosed attached garage and/or

2) equipment that emit CO,

it is imperative that you comply with the Law regardless to avoid preventable harm.


One of the qualifiers in the statute, for example, is that the dwelling at issue is built on or after January 1, 2008.  The significance of this date is that in 2008, CO alarms were required in new construction dwellings that had equipment that could emit CO or an enclosed attached garage.  However, as a practical matter, the risk of harm to occupants is the same for homes built pre-2008 that contain fixtures, appliances etc. that produce CO.  It may surprise you that even storing a used charcoal grill in a garage overnight without dumping out the ash could emit CO, which could filter into the home and harm or be fatal to occupants. Therefore, it is imperative for anyone who owns property with CO-emitting equipment, or a vehicle in an attached garage, to ensure that alarms are operable, long-life (if battery operated), and placed where the statute prescribes.

What are the requirements for the alarm itself?

Similar to the changes in the smoke alarm law effective January 1 of this year, CO alarms must be hardwired with a battery backup or battery-powered with a long-life ten (10) year battery and a sealed tamper resistant compartment.  The alarms can also be connected to an on-site control unit that monitors the CO 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.

Another option is to install a combination carbon monoxide and smoke alarm, which some manufacturers sell; however, the unit must comply with the smoke alarm requirements of Title 9 of the Public Safety Article, meaning that if it is battery operated, it must have a “silence/hush button” as well as be sealed, tamper resistant, and powered by a ten (10) year long-life battery.

Where do CO alarms need to be installed?

For a residential dwelling or a rental dwelling unit, the new Law requires that a CO alarm be placed in a central location outside of each sleeping area (a space that includes one or more sleeping rooms and a hall or common area immediately adjacent to any sleeping room).  In addition, for a rental dwelling, alarms must be installed on every level of the dwelling, including the basement.  For example, applying these requirements, if a qualifying rental dwelling has no CO equipment in the home, but does have an enclosed attached garage, CO alarms must be installed outside of each sleeping area and on every level of the home to include the basement.


For more information about the State’s carbon monoxide alarm law, please see the Office of the State Fire Marshall Media Release at .


Readers with questions about this or any real estate legal matter can reach Dave Parker at 301-590-9300.