The most important thing you can do to protect your home and family from fire is to make sure that your smoke alarms are installed and working properly. Smoke alarms should be placed on every level of your home and within 15 feet of every bedroom. Some units, like this, are hardwired; others use a conventional battery that will last for about 6 months. Remember, smoke alarms don't last forever, most manufacturers recommend replacing the entire unit every 8-10 years. Carbon monoxide is an invisible, odorless, colorless gas created when fuels burn incompletely. In the home, heating and cooking equipment that burn fuel are potential sources of carbon monoxide. Vehicles or generators running in an attached garage can also produce dangerous levels of carbon monoxide. Install CO alarms should be installed in a central location outside each separate sleeping area. CO alarms are not substitutes for smoke alarms.