Never ignore an alarm

When a smoke alarm or carbon monoxide alarm sounds, move to a safe location outside and contact emergency services. Do not remain inside to search for the source of carbon monoxide.

What to do when an alarm sounds

Smoke alarm

Follow the household fire-escape plan, get everyone outside, stay outside, and call the fire department from a safe location. Do not disable an alarm because the source is not immediately visible.

Carbon monoxide alarm

The U.S. Consumer Product Safety Commission advises occupants to move outside to fresh air immediately, call emergency services, account for everyone, and not reenter until responders say it is safe. Do not operate an appliance identified as the source until trained personnel have serviced it.

Headache, dizziness, weakness, nausea, vomiting, sleepiness, or confusion can be symptoms of carbon-monoxide exposure. Get outside and call 911 when exposure is suspected.

Build an alarm inventory

Walk the home with a flashlight and create a simple record for each device:

  • Alarm type: smoke, CO, or combination
  • Location and level of the home
  • Manufacturer and model
  • Power type: replaceable battery, sealed battery, plug-in, or hardwired with backup
  • Manufacture date, installation date, and replace-by date
  • Whether alarms are interconnected
  • Last test and battery-change date

Photograph the front, back label, and installed location. Keep manufacturer instructions with the home records.

Placement basics

CPSC guidance calls for smoke alarms on every level of the home, inside each bedroom, and outside sleeping areas. CO alarms should be on every level and outside sleeping areas. Local law, building type, renovations, ceiling shape, and manufacturer instructions may require additional or different placement.

Follow the product instructions for wall or ceiling placement, distance from cooking appliances, fuel-burning equipment, vents, fans, windows, bathrooms, and areas where furniture or curtains could block the alarm.

Interconnection matters

Interconnected alarms can sound throughout the home when one device detects danger. CPSC and the U.S. Fire Administration recommend interconnected alarms where practical.

Testing, batteries, and nuisance alarms

Test alarms monthly using the manufacturer’s test button or specified procedure. The test button confirms circuitry and sound; it does not recreate a real fire or verify the accuracy of a CO sensor.

Replace batteries according to the manufacturer’s instructions. CPSC advises annual battery replacement for alarms with replaceable batteries unless the instructions specify otherwise. Sealed-battery alarms still need monthly testing and eventual device replacement.

Do not remove batteries to silence cooking or shower steam. The U.S. Fire Administration recommends using the alarm’s hush feature, ventilating the area, and correcting placement problems according to manufacturer instructions.

Know the replacement date

Alarm sensors and electronics do not last forever. The U.S. Fire Administration advises replacing smoke alarms every 10 years. CO-alarm replacement life varies by product, so use the label, end-of-life signal, and manufacturer instructions rather than assuming a universal age.

Replace an alarm that is damaged, painted, contaminated, missing, recalled, beyond its stated life, unable to pass the test procedure, or repeatedly signaling a fault after the recommended troubleshooting steps.

Questions to answer before buying

  • Does the device meet current applicable safety standards listed in the instructions or certification label?
  • Is it compatible with existing hardwired or interconnected alarms?
  • Does local code require a specific type, power source, placement, or interconnection?
  • Can everyone in the home hear and recognize the alarm?
  • Are visual or bed-shaker notification accessories needed?
  • What is the stated service life and replacement signal?
  • Is professional installation required for hardwired work?

A smart notification feature can be useful, but it is not a substitute for a functioning local alarm that occupants can hear. Internet service, phone settings, batteries, and app permissions can fail.

Primary sources

Editorial note: This guide does not replace local fire code, the alarm manufacturer’s instructions, a fire-department assessment, or professional installation. Report corrections to info@homeroutineguide.com.