California smoke alarm, carbon monoxide alarm and water heater strap rules

What does California smoke alarm law require?

Under Health and Safety Code section 13113.7, each home must have smoke alarms approved and listed by the State Fire Marshal, installed the way the maker's instructions say. That covers houses, duplexes and condos, but not manufactured homes or mobilehomes. The Fire Marshal approves those instructions to match the building code, so the instructions tell you where each alarm goes.

The 10-year battery rule. Since July 1, 2014, a smoke alarm that runs only on a battery must have a sealed battery that cannot be removed and lasts at least 10 years, or the Fire Marshal will not list it (section 13114). Alarms listed since 2015 also show their date of manufacture and have a hush button. An older battery alarm that met the rules when it went up still counts, unless your city says otherwise.

Permits. If you pull a permit for a repair, alteration or addition worth more than $1,000, the city will not sign off the job until every required smoke alarm is a listed one. Our Orange County permits guide covers which jobs need a permit.

Which homes need a carbon monoxide alarm, and where?

Under section 17926, any home with a fuel-burning heater or appliance, such as a gas furnace or water heater, a fireplace or an attached garage needs a carbon monoxide device listed by the State Fire Marshal. The deadline was July 1, 2011 for single-family homes and January 1, 2013 for most other homes, so it applies now. A violation can bring a fine of up to $200, after a 30-day notice to fix it.

The State Fire Marshal's carbon monoxide FAQ says to put one outside each sleeping area, and to follow the maker's instructions. Height does not matter much, because carbon monoxide mixes with room air. A combination smoke and CO alarm meets both laws. A CO alarm installed before July 1, 2011 can stay in use, and there is no 10-year battery rule for CO-only alarms, though a battery-only combination alarm needs the sealed battery.

To test both kinds, follow how to test smoke and CO alarms. The county's free hazardous waste centers take old smoke alarms.

Water heater strapping requirements in California

Section 19211 says every residential water heater, new, replacement or existing, must be braced, anchored or strapped so it cannot fall or slide in an earthquake, at least as the California Plumbing Code requires. It covers tanks up to 120 gallons that have a ready-made strapping kit.

The Division of the State Architect's water heater bracing guidelines show how. They call for two sets of straps fastened to the wall studs, the upper one about 9 inches below the top of the tank and the lower one 4 inches above the controls. They were written for tanks of 52 gallons or less; a tank up to 75 gallons needs a third set at mid-height, and bracing for anything larger needs the building department's approval first. A tank in an attic or one not next to a wall also goes to the building department. The State Architect also strongly recommends flexible water and gas connectors.

Replacing a water heater is permitted work. Costs and permits by city are in our water heater replacement cost guide. For the rest of the house, see earthquake retrofitting in Orange County.

What do I owe a buyer or a tenant?

Selling. A single-family home that is sold must have a working smoke alarm, and the seller gives the buyer a written statement saying so (section 13113.8). The seller also certifies in writing that the water heater is strapped, which can go in the transfer disclosure statement.

Renting. If you rent out a house, section 13113.7 makes you test and maintain its smoke alarms and make sure they work when a new tenant moves in. You keep the CO alarms working too, and fix a problem once the tenant tells you about it (section 17926.1).

Just bought? Our new homeowner checklist puts these checks in order with the rest of your first year.

As of November 2026. A city can add stricter rules by ordinance, so your building or fire department has the final word.