Carbon monoxide (CO) is a silent, odorless gas that can be deadly if undetected. In rental properties across California, preventing CO poisoning isn’t just a good practice—it’s the law. With the passage of Senate Bill 183 (SB 183), California established clear legal responsibilities for landlords and tenants to ensure carbon monoxide detectors are properly installed, maintained, and functional. This guide walks through everything rental property owners and tenants need to know about CO detector laws in California, including compliance timelines, installation requirements, responsibilities, and penalties.
Key Takeaways
- CO detectors are mandatory in most California rentals under SB 183 and Health & Safety Code § 13261.
- Landlords must install and maintain certified detectors near sleeping areas and on each level of the dwelling.
- Tenants are responsible for reporting issues and must not tamper with the device.
- Violations can lead to fines up to $200, but landlords have a 30-day cure period before penalties apply.
- Even dwellings with no direct garage access may still be required to have detectors.
Table of Contents
- Legal Overview: California’s CO Detector Laws
- Who Must Comply—and Exemptions
- CO Device Standards & Placement
- Landlord vs. Tenant Responsibilities
- Compliance & Penalties
- Enriching Context: Safety, Maintenance, and Liability
- Conclusion & Final Takeaways
- FAQ
Legal Overview: California’s CO Detector Laws
SB 183 and State Code Requirements
Enacted in May 2010, SB 183—known as the Carbon Monoxide Poisoning Prevention Act—requires carbon monoxide detectors in all “dwelling units intended for human occupancy” in California. Codified under Health & Safety Code § 13261, this law mandates:
- Single-family homes with fossil fuel appliances or attached garages to have CO detectors installed by July 1, 2011.
- Multifamily dwellings, such as apartment complexes, to comply by January 1, 2013.
- Hotels and motels with similar conditions to comply by January 1, 2016.
Civil Code 1954: Entry for Installation
Under Civil Code § 1954, landlords have the legal right to enter a rental unit with 24-hour written notice to install, test, repair, or replace a carbon monoxide detector.
Who Must Comply—and Exemptions
Required Scenarios
CO detectors are required in any California dwelling that:
- Has appliances or heating systems powered by fossil fuels (e.g., gas stoves, furnaces).
- Includes a fireplace that burns wood or gas.
- Has an attached garage, regardless of whether it has direct access to the unit.
- Features central heating systems in common areas that serve multiple units.
Even electric-only apartments with a shared fossil fuel-powered system in a hallway or basement require detectors installed in hallways and shared spaces.
Exemptions
Properties that do not use any fossil fuels and do not contain enclosed spaces where CO can accumulate—such as electric-only apartments with no attached garages or gas sources—may be exempt. Always confirm with your local fire marshal to ensure proper classification.
CO Device Standards & Placement
Certification Requirements
CO alarms must be certified by national testing agencies such as:
- Underwriters Laboratories (UL)
- American National Standards Institute (ANSI)
California also mandates devices listed by the California State Fire Marshal’s Office, tested under UL 2034 for alarms or UL 2075 for system detectors. Combination smoke/CO alarms are acceptable if both alerts have distinct audible tones.
Power Options and Device Life
Approved CO detectors may be:
- Battery powered
- Plug-in with battery backup
- Hardwired with battery backup
Most devices have a life expectancy of 7 years, though some newer sealed battery models last up to 10 years. Manufacturers are required to include installation instructions compliant with building codes.
Placement Guidelines
According to California Building Code:
- Install detectors outside each separate sleeping area.
- Place them on every level of the home, including basements.
- Position at least 4 inches away from exterior walls and 4 feet from HVAC vents.
- In multi-unit housing, place detectors in shared hallways and common areas if fossil-fuel systems are present.
The State Fire Marshal recommends that each bedroom also have a detector for optimal protection.
Landlord vs. Tenant Responsibilities
Landlord Responsibilities
- Install, repair, test, and maintain CO detectors before tenant move-in.
- Use certified devices and follow installation placement code.
- Provide notice and access for maintenance under Civil Code § 1954.
Tenant Responsibilities
- Notify the landlord immediately if the detector malfunctions.
- Do not tamper with, disable, or remove the CO detector or its batteries.
- Keep the device unobstructed and allow maintenance access.
If a tenant removes or disables the device without notifying the landlord, the owner is not held liable under the law.
Compliance & Penalties
Functional at Move-In
The carbon monoxide detector must be fully functional at the time the tenant takes possession of the unit. This includes functioning batteries and proper installation.
Cure Period and Fines
If a violation is found, the landlord must be given a 30-day notice to correct before any fine is imposed.
- Maximum fine: $200 per violation
- Landlords are not penalized if the tenant fails to notify about removal or malfunction
Enriching Context: Safety, Maintenance, and Liability
The Silent Danger
CO is often called the “silent killer”. It’s colorless, odorless, and can be fatal. In the U.S., CO poisoning causes over 400 deaths and 20,000 emergency visits per year.
Maintenance Tips
- Test detectors monthly using the test button.
- Replace batteries annually (unless sealed).
- Monitor for end-of-life signals from the device.
- Replace devices when expired (typically every 7–10 years).
Liability Risks
Failing to comply with CO detector laws could expose landlords to:
- Legal liability in the event of CO-related injuries
- Insurance claim denials
- Tenant lawsuits or habitability claims
Conclusion & Final Takeaways
Landlords and property managers across California have a legal and ethical responsibility to protect tenants from carbon monoxide risks. Ensuring detectors are properly installed, maintained, and tested isn’t just about compliance—it’s about safety. Tenants also play a vital role by reporting issues and respecting the device’s function.
Understanding and following SB 183 and Health & Safety Code § 13261 will keep your property compliant, safe, and liability-free.
FAQ
When did California require CO detectors in rentals?
SB 183 took effect in 2010. Single-family rentals had a deadline of July 1, 2011. Multifamily units by January 1, 2013.
Are combination smoke and CO detectors allowed?
Yes, as long as each function emits a distinct audible tone.
Where should I place a CO detector?
Outside sleeping areas, in each level of the dwelling, in basements, and in shared hallways for multifamily housing.
What if the tenant removes the detector?
The landlord is not in violation unless they were notified and failed to act.
