Hardwired CO alarms and combination smoke and CO alarms connect to a household circuit and to each other, so a leak detected near the furnace also sounds upstairs. A local electrician can install them where they will do the most good.
Which Homes Need CO Alarms and Where
Current code generally requires CO alarms outside each sleeping area in homes that have fuel-burning appliances or an attached garage, and on each level in many cases. Alarms are also placed in bedrooms that contain a fuel-burning appliance. Some jurisdictions add requirements when a home is remodeled, so check with your city or county.
Standalone CO alarms, combination smoke and CO alarms, and plug-in units with battery backup are all available. Hardwired combination units reduce the number of devices on the ceiling and tie CO warnings into the same interconnected system as the smoke alarms, with a distinct alarm pattern or voice warning for each.
When CO Alarms Belong on the List
- The house has gas heat, a gas water heater or a gas range
- There is a wood or gas fireplace in use
- An attached garage shares a wall or ceiling with living space
- You use a portable generator during outages
- Existing CO alarms are past their end-of-life date
- You are updating smoke alarms and want combination units
Warning Signs to Take Seriously
- Headaches, dizziness or nausea that ease when you leave the house
- Several people or pets feeling sick at the same time
- Soot or yellow flames around a gas appliance
- A CO alarm that chirps or displays an end-of-life signal
Planning a CO Alarm Installation
The electrician maps fuel-burning appliances, the garage connection and bedrooms, then places alarms outside sleeping areas and on each level, following the alarm manufacturer's mounting guidance. Where smoke alarms are already hardwired, combination units can often replace them on the same interconnected circuit if the models are compatible. The electrician does not repair gas appliances or venting; if a problem there is suspected, a qualified HVAC or gas technician should check it.
- Locations of furnaces, water heaters, ranges and fireplaces
- Placement outside each sleeping area and on each level
- Interconnect compatibility with existing smoke alarms
- Distance from the garage door, fuel appliances and bathrooms
- End-of-life dates on existing units
Safety first. If a CO alarm sounds, get everyone, including pets, outside into fresh air right away and call 911 or the fire department from outside. Do not go back in until responders say it is safe. Never run a portable generator, grill or vehicle inside a garage, even with the door open, and keep generators well away from windows and doors. A whole-home standby unit set up by professionals is the safer long-term answer for frequent outages, covered in the home generator guide.
How it usually works
Call to get started
Describe your fuel-burning appliances and garage setup, and you'll be connected with a local electrician.
Placement walk-through
The electrician identifies required and recommended alarm locations.
Install and interconnect
Hardwired or combination alarms are mounted and tied into the alarm system.
Test and explain
Alarms are tested and you learn the difference between the smoke and CO warning sounds.
For Birmingham-area homes
Storm season across the Birmingham area brings power outages, and outages bring portable generators. Every year people are hurt by generators running in garages or too close to open windows. Many homes in Hoover and other suburbs built from the 1980s onward also have attached garages and gas furnaces tucked into attics or basements. A working, interconnected CO alarm system is a sensible safeguard against both situations; for homes that lose power often, consider a properly installed generator instead of a portable unit near the house.
Related electrical problems
Noticing one of these? Each guide explains likely causes and what's safe to check before you call about carbon monoxide detector installation.