Smoke Detector & Carbon Monoxide Checklist for Landlords
June 30, 2026Smoke and carbon monoxide detector requirements are one of the more universally regulated safety items across states — nearly every state requires them in some form — but the specifics (which rooms, battery vs. hardwired, who tests them) vary enough that it's worth confirming your state's exact rules rather than assuming.
Common requirements across states
Most states require, in some combination:
- • A working smoke detector in or near every bedroom, and at least one on every level of the unit
- • A carbon monoxide detector if the unit has a fuel-burning appliance (gas furnace, gas water heater, fireplace) or an attached garage
- • A functioning detector at the start of every new tenancy, verified before move-in
- • A process for tenants to report a non-working detector, and a landlord obligation to repair or replace it promptly
Who is responsible for what
In most states, the landlord is responsible for installing detectors and ensuring they work at move-in, while ongoing responsibility for battery replacement is often split by state law or lease terms — some states put battery maintenance on the tenant once a working unit and fresh battery are provided at move-in, others keep it on the landlord throughout. Spell this out clearly in the lease rather than assuming.
A simple move-in and periodic checklist
Use this as a starting checklist, and confirm against your specific state and local code:
- • Smoke detector present in every bedroom — tested and working
- • At least one smoke detector on every level of the unit, including basements if applicable
- • Carbon monoxide detector present if there is a fuel-burning appliance or attached garage
- • Detector installation date noted (many models have a manufacturer expiration, commonly around 10 years)
- • Fresh batteries installed at move-in, if battery-powered
- • Tenant acknowledgment (signature) that detectors were tested and working at move-in
Frequently Asked Questions
How often should smoke detectors be tested?
A common recommendation is monthly testing, with battery replacement at least annually (or immediately when a low-battery warning sounds) — though who is responsible for this ongoing testing (landlord vs. tenant) depends on your state and lease terms.
Do I need carbon monoxide detectors if my unit is all-electric?
Many states only require carbon monoxide detectors when there's a fuel-burning source (gas, oil, wood) or an attached garage — an all-electric unit with no attached garage may not trigger the requirement in some states, but check your specific state and local code rather than assuming.
What happens if a detector is missing or not working when a tenant moves in?
This can create real legal exposure — many states treat working smoke detectors as a basic habitability requirement, and a fire or injury linked to a missing or non-working detector is a serious liability issue, separate from any statutory penalty for the code violation itself.