Replacing smoke and carbon monoxide alarms: what you, a handyman or an electrician should do
Updated · KeystoneProGuide editorial team
Who should install a smoke alarm?
It depends on how it is powered. A battery alarm is a job for you or a handyman. A hardwired alarm, which runs on the home's electrical system, is not: the U.S. Fire Administration says only qualified electricians should install hardwired smoke alarms. In Philadelphia, electrical work also needs a city electrical license, and many suburban townships license electricians too.
The difference matters most when an old hardwired alarm reaches the end of its life: putting in its hardwired replacement is electrical work.
Why bother?
Because working alarms save lives. The National Fire Protection Association says roughly three of every five home fire deaths happen in homes with no smoke alarms or none that work, and that the risk of dying in a home fire is cut in half in homes with working alarms.
Where do smoke alarms go?
The Fire Administration's placement advice is to put alarms inside and outside each bedroom and sleeping area and on every level of the home, mounted on the ceiling or high on the wall. The NFPA adds the basement. Both recommend interconnected alarms, so that when one sounds they all do; wireless models communicate without new wiring.
The Fire Administration also notes that your city, county or state may require a particular type of alarm, and suggests checking with the local fire marshal.
Which type should you buy?
The Fire Administration recommends both ionization and photoelectric alarms, or dual-sensor alarms that combine them, because the two detect different types of fire. It gives typical prices: ionization or photoelectric alarms from $6, dual-sensor from $24, and wireless interconnected alarms from $40. There are also alarms for people with hearing loss that flash a strobe or vibrate.
When do alarms need attention?
- Every month: test them.
- Every year: replace 9-volt batteries, and the backup battery in hardwired alarms.
- At 10 years: replace the whole alarm, counting from the manufacture date printed on it. Alarms with a sealed 10-year battery are replaced whole, following the maker's instructions.
What about carbon monoxide alarms?
They are a separate device with their own rules. The Consumer Product Safety Commission says more than 200 people in the U.S. die each year from accidental carbon monoxide poisoning linked to consumer products. Its advice is to install battery-operated or battery-backup CO alarms on every level and outside sleeping areas, with interconnected alarms best.
The CPSC's fact sheet adds detail a handyman should know:
- Choose an alarm that meets the UL 2034 standard.
- Do not put CO alarms in kitchens, directly above fuel-burning appliances or next to heating vents.
- The test button checks the circuitry, not whether the sensor is accurate. Alarms have a replacement age, and newer ones give an end-of-life signal.
- An alarm is added protection, not a substitute for proper use and upkeep of fuel-burning appliances.
- Many states and localities require CO alarms; ask the local building code official.
What should happen when an alarm sounds?
For a CO alarm, the CPSC says not to search for the source. Get everyone outside, call 911 or the fire department, and stay out until responders say it is safe. If a malfunctioning appliance is to blame, do not use it again until trained personnel have serviced it. For any alarm, the CPSC's winter safety advice is never to ignore it: get outside at once and call 911.
Can a handyman fix the cause of a CO alarm?
No. The CPSC says carbon monoxide comes from the incomplete burning of fuels such as natural gas, oil, propane and wood, so the cause lies in an appliance, chimney or vent, and it says never to service fuel-burning appliances without proper knowledge, skill and tools. It urges a yearly professional inspection of furnaces, boilers, water heaters, fireplaces, chimneys, flues and vents. That is work for a heating contractor or chimney professional. One thing a handyman on a renovation job can do: the CPSC says to make sure tarps and debris do not block appliance vents and chimneys while work is under way.
Where can you get free alarms or help?
- Your fire department. The Fire Administration says some fire departments offer reduced-price or free smoke alarms, and some install battery alarms at no cost.
- Weatherization. Pennsylvania's Weatherization Assistance Program, for households at or below 200% of the federal poverty guidelines, includes installing carbon monoxide alarms among its health and safety work.
- Older relatives. The CPSC's older adult safety page repeats the placement advice for seniors: smoke alarms in every bedroom, outside every sleeping area and on every floor, and a CO alarm outside sleeping areas.
What does an alarm job cost?
The alarms themselves start at the Fire Administration's prices above. Fitting battery units is a small job, so a handyman's minimum charge may be most of the bill; hardwired units need an electrician. The cost guide explains minimum charges, the how-often guide puts alarm checks on a calendar, and the electrical, plumbing and gas guide explains where wiring work stops being a handyman's.
Sources
- Get an Electrical Contractor License, City of Philadelphia
- Carbon Monoxide Fact Sheet, U.S. Consumer Product Safety Commission
- Home Heating Equipment, U.S. Consumer Product Safety Commission
- Winter Storm May Knock Out Power; CPSC Warns of Deadly Carbon Monoxide and Fire Risks, U.S. Consumer Product Safety Commission
- Older Adult Safety, U.S. Consumer Product Safety Commission
- Smoke Alarms, U.S. Fire Administration
- Learn More About Smoke Alarms, National Fire Protection Association
- Carbon Monoxide Information Center, U.S. Consumer Product Safety Commission
- Weatherization in PA, Pennsylvania Department of Community and Economic Development