Where CO alarms belong
Carbon monoxide comes from incomplete combustion — gas appliances, fireplaces, vehicles running in attached garages and generators. CO alarms are generally placed outside each sleeping area and on every level of the home, following the manufacturer's instructions.
Hardwired alarms with battery backup can be interconnected with your smoke alarms, so any alarm sounds throughout the house. Combination units simplify installation where both are needed.
What the work typically involves
Identify CO sources
Note gas appliances, fireplaces, garages and generator locations.
Plan locations
Place alarms near sleeping areas and on each level.
Install and interconnect
Wire alarms with battery backup and interconnect with existing alarms if compatible.
Test
Test each alarm and explain what to do if one sounds.
Common reasons homeowners call
- Switching to gas appliances
- Adding a generator
- Finishing a basement near the furnace
- Replacing expired CO alarms
- Home sale or rental requirements
Warning signs
- No CO alarms near bedrooms
- CO alarms past their end-of-life date
- Unexplained headaches or nausea that improve away from home
- Generator used near the house
- Soot or yellow flames at gas appliances
Safety considerations
If a CO alarm sounds: If a CO alarm sounds, get everyone outside to fresh air immediately and call 911 or your gas provider's emergency line. Don't go back in until responders say it's safe.
What an electrician will check
- Alarm locations near sleeping areas
- Each level of the home
- Interconnection compatibility
- Alarm age
- Proximity to fuel-burning appliances
Related electrical problems
Related residential services
Smoke Detector Installation
Hardwired, interconnected smoke alarm installation and replacement with battery backup.
Generator Installation
Standby and portable generator hookups with transfer switches or interlocks for safe backup power.
Whole Home Generator
Permanently installed standby generators sized to power your entire home automatically during outages.
Electrical Inspection
Whole-home electrical safety inspections for older homes, home purchases, renovations and insurance questions.
Frequently asked questions
Generally outside each sleeping area and on each level of the home. Follow manufacturer placement guidance.
Many CO alarms have an end-of-life signal and need replacement after several years. Check the manufacturer's guidance.
Yes. Combination alarms detect both and can simplify installation.