Smoke detectors should generally be replaced every 10 years, according to the U.S. Fire Administration, or sooner if the manufacturer’s instructions call for it or the alarm fails a test. Changing the battery does not reset an alarm’s service life, because the sensor itself wears over time.
Knowing your alarms’ age is the first step.
How to Tell How Old Your Alarms Are
Most smoke alarms have a manufacture date printed on the back or side. Because the alarm usually has to be removed from its base to read the label, and hardwired alarms are connected to household wiring, it may be easier to have an electrician check the dates on hardwired units. Writing the installation date on a small label nearby can make future checks easier.
If an alarm has no visible date or you do not know when it was installed, it is reasonable to assume it may be due for replacement. Alarm models vary, so follow the replacement guidance from the manufacturer of your specific alarm.
End-of-Life Signals and Malfunctions
Many newer alarms give an end-of-life signal, such as a specific chirp pattern or a light, when they reach the end of their service life. These signals are different from a low-battery chirp, and the alarm’s instructions explain what each one means.
If you are unsure which signal you are hearing, check the model number against the manufacturer’s instructions before deciding what to do.
An alarm should also be replaced if it does not sound when tested, keeps chirping after a battery change, gives frequent false alarms that are not explained by cooking smoke or steam, or shows visible damage. The USFA recommends testing smoke alarms monthly.
Batteries Versus Replacing the Whole Alarm
Replacing batteries keeps an alarm powered, but it does not extend the life of the sensor. Hardwired alarms also have backup batteries that need replacing as recommended. Some alarms have sealed batteries designed to last the full life of the alarm, and the entire unit is replaced at the end.
Never disable or remove a smoke alarm because it chirps or causes nuisance alarms. Address the cause or replace the alarm instead.
Interconnected Systems and Professional Replacement
In homes with interconnected alarms, replacements usually need to be compatible with the rest of the system. Some homeowners replace all alarms at once so they share the same age and model and continue to communicate properly. Replacing them together also simplifies tracking when the next replacement is due.
Hardwired alarms connect to household wiring and should be replaced by a qualified electrician. Requirements may also apply in Utah depending on the home and the work being done.
If your alarms are approaching 10 years old in Salt Lake City, our smoke detector installation services can check their age and replace them with compatible alarms.