State of California Carbon Monoxide Detector Requirements


Owners of rental/leased units are required to install, repair, maintain and test the CO devices pursuant to Civil Code 1954, which allows them to enter the unit with 24-hour notice. Tenants are required to notify the property owner or manager if the CO device is not functioning properly and not to tamper or deactivate the device.

California enacted SB 183, known as the Carbon Monoxide Poisoning Prevention Act, in May 2010. The law (Cal. Health & Safety Code § 13261) codified the state’s building code that all ‘dwelling units intended for human occupancy’ be required to have a carbon monoxide detector.  

What Rental Housing Requires a Carbon Monoxide (CO) Detector?

  • All single-family homes with heating systems and appliances that use fossil fuels are required to have Carbon Monoxide (CO) detectors in by July 1, 2011.
  • Multifamily housing complexes with heating systems and appliances that use fossil fuels are required to  have CO detectors in each unit by January 1, 2013.
  • If the dwelling unit (single, multifamily, or other housing type) has an attached garage, fireplace, appliance, or heating system that emits carbon monoxide as a byproduct of combustion, it is required to have CO detectors.
  • Apartments with attached garages with no direct access to the apartment and no fossil fuel appliances are still required to have a CO detector- CO detectors must be installed in multi-unit occupancies if there is fossil fuel burning appliances or attached garages.   
  • Dwellings without direct access from the garage to the living area are still required to have CO detectors because CO from the garage can still travel into openings and throughout the ventilation systems oft he living space.  
  • State law also requires CO detectors in two-story apartment buildings with electric appliances that have a common hallway, but have a central heating system powered by a fossil fuel. CO detectors are required in common areas and hallways leading to the living units because CO can enter the living units through its ventilation systems.
  • Any type of housing that does not use fossil fuels or emit carbon monoxide in an enclosed space or from a balcony could be exempt from having CO detectors – be sure to verify with your local fire marshal to make sure that your property is to make sure that your property is exempt.

Building Code Requirements 
The Carbon Monoxide (CO) detector must be certified by national testing labs, such as the American National standards Institute (ANSI) and Underwriters Laboratories Inc.

Manufacturers of CO devices are to include installation instructions that are in compliance with applicable building codes. CO devices may be battery powered or plug-in devices with battery back-ups. The life expectancy of these devices is typically seven years, but it could be shorter. 

CO devices are required to have a distinct audible sound. If the detector is a combination device such as a fire/smoke and CO detector), the device must have a distinct audible sound for each function. The law is silent in regard to devices for the hearing impaired, but such devices could be considered a reasonable accommodation, and it might even be a good idea for a landlord to install such a device if one is requested. 

California’s Building Code states that detectors should be installed outside of each separate sleeping area in the immediate vicinity of each bedroom in every dwelling unit and on every level for minimal security. However, the State Fire Marshal’s Office still recommends that each sleeping room have a CO detector for maximum detection. The device should be located at least 4 inches from all exterior walls and at least 4 feet from supply or return vents. CO devices also should be installed in basements where fuel-fired appliances are installed and in all dwelling units that have attached garages.

The device must be functioning at the time the tenant takes possession of the dwelling unit. The tenant also is required to notify the owner if the device is not functioning or working properly. If the CO device or its batteries were removed or unplugged and the owner is not notified, the owner will NOT be in violation of the law. Violations are punishable by a maximum fine of $200 per violation, but the law requires that property owner receive a 30-day notice to correct prior to the imposition of a fine. 

If you are a SCRHA member, please log in to your account to download Form 233, Carbon Monoxide Detection Device Addendum for more information. Not a member? Join today to access the full white paper and Form 233: Carbon Monoxide Detection Device Addendum.