When You Change Your Clocks, Check Your Alarms

When you change your clocks in the spring and fall, check your smoke and carbon monoxide (CO) alarms too. Put in fresh alkaline batteries if your alarms use them, and replace the alarms if they're out of date.

Working smoke and CO alarms are your family's first line of defense against an emergency at home. They should be installed on every level of your home and tested every month.

When you change your clocks each spring and fall, remember to check your alarms and change their batteries if necessary. Replace outdated alarms right away and put fresh alkaline batteries in alarms that use them.

Replace Aging Smoke and CO Alarms

Alarms don’t last forever. Look on the back of your alarm for the manufacturing date. Replace smoke alarms after 10 years. Replace carbon monoxide alarms after 5, 7, or 10 years, depending on the model. If your alarm is out of date, or if there’s no date at all, it’s time to replace the alarm right away. Learn more about smoke and CO alarms.

What to Look for in Replacement Smoke Alarms

Most older homes in Massachusetts use single-station, battery-powered smoke alarms. Replacement alarms in these homes should have a sealed, long-life battery and a "hush" to prevent users from disabling them. To be sure you and your loved ones are protected, select photoelectric alarms from a well-known national brand and test them once a month.

Always look for the mark of an independent testing lab such as UL or Intertek/ETL. Alarms that meet UL Standard 217, 8th Edition or later, use the latest multi-criteria technology to prevent nuisance alarms caused by cooking smoke. Look for this language on the packaging or product specifications.

More modern homes should have hardwired, interconnected smoke alarms. These alarms must also be replaced after 10 years.

Check Carbon Monoxide (CO) Alarms

CO kills hundreds of people each year. Thousands more are hospitalized. Many cases of CO poisoning involve furnaces and heating appliances. But CO is also produced by stoves, grills, vehicles, and generators.

We can’t see, smell, or taste carbon monoxide. Working CO alarms are the only way to detect this invisible killer.

Check and test your CO alarms at the same time you test and check your smoke alarms. Learn more about CO safety.

Create and Practice a Home Escape Plan

You could have less than three minutes to escape a fire at home. Create and practice a home escape plan that includes two way out of every room. Everyone in the house should know what to do and where to go when the alarm sounds. This includes young children, older adults, and persons with disabilities. Keep doorways, stairways, and windows clear of furniture and other obstructions so you can leave quickly and safely. Learn more about home escape plans.

Older Adults at Greatest Risk

Adults over the age of 65 are at higher risk of dying in fires than other age groups. Do you know a senior who needs help testing, maintaining, or replacing smoke alarms? They can contact the local fire department or senior center for help. Learn more about fire safety for older adults.

Last updated:	October 22, 2025