I think you mean CO. CO2 is carbon dioxide, which is harmless in small concentrations. Our bodies actually produce and exhale it.
CO is carbon monoxide which is colorless, odorless, tasteless and deadly, even at very small levels.
CO results from the incomplete combustion of materials containing carbon. If your home is all electric, you really have no need for a CO detector.
Yes, I know the difference, I made a mistake. Acknowledged three times now.