California Code, Health and Safety Code - HSC § 17926.1

(a) An owner or owner's agent of a dwelling unit intended for human occupancy who rents or leases the dwelling unit to a tenant shall maintain carbon monoxide devices in that dwelling unit consistent with this section and Section 17926.

(b) An owner or the owner's agent may enter any dwelling unit intended for human occupancy owned by the owner for the purpose of installing, repairing, testing, and maintaining carbon monoxide devices required by this section, pursuant to the authority and requirements of Section 1954 of the Civil Code.

(c) The carbon monoxide device shall be operable at the time that the tenant takes possession. A tenant shall be responsible for notifying the owner or owner's agent if the tenant becomes aware of an inoperable or deficient carbon monoxide device within his or her unit. The owner or owner's agent shall correct any reported deficiencies or inoperabilities in the carbon monoxide device and shall not be in violation of this section for a deficient or inoperable carbon monoxide device when he or she has not received notice of the deficiency or inoperability.

(d) This section shall not affect any rights which the parties may have under any other provision of law because of the presence or absence of a carbon monoxide device.

(e) For purposes of this section, with respect to a time-share project, “owner” means the homeowners' association of the time-share project.