About the question，we think we must know about the below fact：
Smoke detectors are a must in all homes, they can help your family warn whether fire happen. and carbon monoxide detectors are needed for any home with fuel-burning appliances such as a furnace, water heater, range, cooktop, or grill.especially for cold winter ... You should also have a carbon monoxide detector on each living level, in the basement, and near (not inside) an attached garage.
now, let‘s come back this question ：do most smoke detectors detect carbon monoxide?. our answer is not and most smoke detectors do not detect carbon monoxide. unless the detector is smoke detector and co detector combination alarm. The combined detector is good product of technological development. it is our top pick because it detects both smoke and carbon monoxide, features beeping alerts.
the smoke detector and co detector combination alarm can do the work of two item.
So if you want to install smoke detector and carbon monoxide detector. you can choose a single unit that serves as a smoke detector or carbon monoxide detector only, or a smoke detector and co detector combination alarm unit that handles both duties.