If that annoying chirping just won’t stop, even after you replaced the battery, it is probably  the “end-of-life warning” for the CO alarm. Underwriters Laboratories (UL) began requiring in 2009, as a condition for gaining a UL rating, that manufacturers alert homeowners when their carbon monoxide alarm has reached the end of its useful life.

    The clock starts when you first power up the alarm, and the lifespan rating varies from 7 to 10 years. When time runs out, each manufacturer alerts you a little differently. First Alert’s signal is five beeps every minute, for example, while Kidde’s end-of-life is a chirp every 30 seconds. If there is a digital display, you may see an ERR or END code.

    The beeping will keep going until the alarm is out of power or, for models with an end-of-life hush feature, the alarm can be silenced for 3-day intervals for up to 30 days. Also, the combo CO and smoke alarms will have the same end-of-life beeps too. 

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Here’s links to a collection of our blog posts about SAFETY: 

• Why is it important to use "cabinet screws" to mount the upper cabinets in the kitchen?

• Is the door between an attached garage and the house required to have a closer (self-closing device)?

• Can the smoke sensors in a home security/fire alarm system replace the smoke alarms required by the building code?

• Should I get a lightning rod system to protect my house? 

• What are the "Aging In Place" features to look for when buying a retirement home?

• What is aging in place? 

• How do I safely remove a dead rodent (rat, mouse or squirrel) from the attic?

• Does pushing the test button on a smoke alarm test the smoke sensor device inside? 

• What is the minimum height of a ceiling fan above the floor?

• Should a smoke alarm be installed in the kitchen? 

• Why is a double cylinder deadbolt lock on an exterior door a safety hazard? 

• Why are rubber washing machine hoses a safety risk?

• What can I do to avoid kitchen accidents and injuries?

• Where are smoke alarms required to be located? 

• Are carbon monoxide alarms required to be installed in homes in Florida?

• Are old vinyl tile floors dangerous?  

• How can I use safety checks to limit my tenant liability for a rental house?

• Do you inspect for trip hazards around the home? 

• When should I replace my smoke alarms?

• Why is an anti-tip device now required behind the range? 

• What are the hazards to avoid when going into an attic? 

• What are the warning signs of a dangerous deck?

     Visit our SAFETY page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.