How Often Should Smoke Detectors Be Replaced?

Every smoke detector — hardwired or battery — must be replaced 10 years from its manufacture date, not from its install date. The sensing element degrades chemically and cannot be tested against. Look for the manufacture date printed on the back.

California requires interconnected hardwired smoke detectors with battery backup in every bedroom, in the hallway outside each sleeping area, and on every level of the home. Homes sold in California must be compliant at close of escrow.

Carbon monoxide detectors are required outside each sleeping area and on every level with a fuel-burning appliance or attached garage. Combination smoke/CO units satisfy both requirements.