Reviewed August 2026 · California
Smoke and Carbon Monoxide Detector Rules
Every California rental needs working smoke alarms in each bedroom, outside sleeping areas, and on every level — plus carbon monoxide alarms wherever there is a fuel-burning appliance, fireplace, or attached garage.
At a glance
- Smoke alarms
- Every bedroom + outside + each level
- CO alarms
- Fuel appliance, fireplace, or attached garage
- Battery type
- 10-year sealed for battery-only units
- Landlord duty
- Install, test at each vacancy, maintain
- Statute
- Health & Safety Code §13113.7, §17926
Smoke alarms
Smoke alarms are required inside each bedroom, outside each sleeping area, and on every level of the dwelling, including basements. In multi-family buildings they are also required in common stairwells and hallways.
Battery-operated alarms sold and installed in California must have a non-replaceable, non-removable battery capable of lasting ten years. Alarms must be listed by the State Fire Marshal and display the manufacture date.
Carbon monoxide alarms
A carbon monoxide alarm is required in any dwelling that has a fossil-fuel-burning appliance, a fireplace, or an attached garage. Placement follows the manufacturer's instructions, generally outside each sleeping area and on every level.
All-electric units with no fireplace and no attached garage are outside the requirement — but the moment a gas range, gas water heater, or attached garage is present, the alarm is mandatory.
Who is responsible for what
| Duty | Landlord | Tenant |
|---|---|---|
| Install compliant alarms | Yes | No |
| Test and repair at each vacancy | Yes | No |
| Replace alarms at end of life | Yes | No |
| Routine testing during tenancy | No | Yes |
| Notify landlord of an inoperable alarm | No | Yes |
Common questions
Where are smoke alarms required in a California rental?
Inside every bedroom, outside each separate sleeping area, and on every level of the unit including basements. Multi-family buildings also need them in common stairwells and hallways.
Does every California rental need a carbon monoxide detector?
Only units with a fossil-fuel-burning appliance, a fireplace, or an attached garage. An all-electric unit with none of those does not require one.
Who replaces the batteries — landlord or tenant?
The landlord installs, tests at each vacancy, and replaces alarms at end of life. During the tenancy the tenant is responsible for routine testing and for notifying the landlord of a failed alarm. Battery-only alarms must have sealed ten-year batteries.
Sources
This is general information, not legal advice. California law changes every year and local ordinances often go further than state law. Check your city and county rules, and talk to a California attorney before acting on anything here.