Choosing a detector
Carbon monoxide detectors do not work as smoke detectors, and smoke detectors do not detect carbon monoxide, unless the unit is clearly a combined smoke and CO alarm. Choose an alarm certified to a recognized standard:
Where to put them
- On every level of the home, including the basement.
- Outside each sleeping area, close enough to wake people.
- Near rooms with fuel-burning appliances and any attached garage, following the manufacturer’s distance guidance.
- Not in bathrooms, directly above cookers, or beside windows, vents or fans that would dilute the reading.
Always follow the manufacturer’s instructions for height and position. State and local codes may also set specific requirements, especially for rentals and new construction.
Testing and replacing
- Test monthly with the test button.
- Replace batteries as the manufacturer instructs, or when the low-battery chirp sounds.
- Replace the whole alarm by the date printed on it. If there is no date printed on the alarm, write the date on it with a permanent marker. The alarm will last the life of its battery: when it starts beeping (between 5 and 7 years), it’s time to replace it. Sensors wear out.
- Don’t put it off. CO alarms are not expensive, but will potentially save your life for the cost of just a few cents a month.
An alarm past its replace-by date can stay silent exactly when it is needed.
If it goes off
- Get everyone out, leaving the door open behind you.
- Call 911 or the fire department from outside or a neighbor’s home.
- Do not go back in until responders say it is safe.
- Get medical care for anyone with symptoms, and say you suspect carbon monoxide.
Afterwards, have the source found and fixed by a qualified professional before using the appliance again, and keep a note of the date, time and any readings.
Questions
My alarm went off then stopped. Is it a false alarm?
Assume it is not. Levels can rise and fall as appliances cycle on and off. Leave, call the fire department and have it checked.
Does my rental or hotel have to have one?
Many states and cities require carbon monoxide alarms in rentals and lodging with fuel-burning appliances or attached garages. The rules vary, so check where you are.