New Hampshire Carbon Monoxide Detector Law

The Law in Plain English

Required in all dwellings with fuel-burning appliances or attached garages.

What This Means for Homeowners & Renters

New Hampshire law requires carbon monoxide detectors in all dwellings with fuel-burning appliances (gas furnaces, boilers, water heaters, fireplaces) or attached garages — a requirement in effect since 2008. If your home has any of these features, detector installation is a legal obligation and a critical safety measure. Homes without these specific features are not covered by state law but may still benefit from CO protection — portable or plug-in sources like gas stoves and outdoor equipment can produce dangerous CO concentrations indoors. Landlords are legally required to provide compliant detectors in rental units with these features.

Landlord Requirements in New Hampshire

Landlords are required to install and maintain CO detectors in rental units.

If you are a renter and your landlord has not provided a working CO detector, you have the right to request one in writing. Document the request and keep a copy. In most states with a landlord mandate, failure to provide a detector is a code violation that can be reported to local housing authorities.

Recommended CO Detector Placement

Regardless of what New Hampshire law requires, safety experts recommend placing CO detectors on every level of your home, within 10 feet of each sleeping area, and near any fuel-burning appliance (furnace, water heater, gas stove, fireplace). Replace your CO detector every 5–7 years — electrochemical sensors degrade over time regardless of whether the device appears functional.