Now that winter is here, the widows are closed and the furnace is on, New Fairfield Volunteer Fire Department says it's time to make sure carbon monoxide detectors are working and placed correctly.  Every fuel-burning appliance, including a gas furnace, produces some levels of carbon monoxide. Normally those gasses are carried out of the home, but if something goes wrong it could result in a CO leak.  In order to best detect CO leaks in the home, carbon monoxide detectors should be placed on every level of the home.  New Fairfield firefighters that this will maximize the protection of families from excess levels of carbon monoxide.