Easy ! Well, most of the time but not always.
Most combo detectors have two vents. Most smoke (only) detectors only have one vent. But to be sure, read the instructions on the back of the unit, and it will tell you if the detector is only a smoke detector or is a combination unit and detects carbon monoxide.
One Vent – Smoke Detector (usually)
Two Vents – Combo detector (almost always)
Some units, like First Alert, do not have two vents. Some Kidde units are combo units and will only have one vent. But usually if the unit has two vents, it is a combo unit. To be sure, take the unit off and read the back to see what it is to be sure.
Call us with any questions you may have at 310.800.4418.