Proper Burning

A properly burning gas heater should produce a clear and steady, blue-colored flame. The blue is the direct result of the chemical make up of natural gas. When natural gas is refined to a gaseous state, the propane, pentane, butane and other hydrocarbons are essentially removed and methane is left to burn. Because methane has an extremely low carbon composition, burning produces very low levels of carbon emissions. The blue flame is the product of complete carbon combustion. Propane, a byproduct of natural gas, also burns blue, but may have a tinge of yellow at the tip of the flame.

Improper Burning

The enchanting yellow and orange flames commonly enjoyed at a camp fire may be a signal of problems in your furnace. A wavering yellow or orange flame is an indication that your furnace is not working properly. This could be an indication of a clog in the burner that is preventing the proper air and gas mixture needed for efficient combustion. If you notice a yellow flame in your furnace, call a professional immediately. Your furnace may be emitting potentially dangerous carbon monoxide.

Dangers

An inefficient gas furnace may not only cost money, it could pose a serious health threat to you and your family. While in its natural state, natural gas is essentially odorless. Manufacturers mix a chemical known as mercaptan to the gas as a safeguard. Mercaptan produces the rotten egg smell that is associated with a gas leak. If your furnace is burning a yellow flame or you notice a rotten egg smell, these are indicators that you could be exposed to dangerous levels of carbon monoxide. Exposure can cause carbon monoxide poisoning with symptoms that include, nausea, dizziness, loss of consciousness and in extreme cases, death.

Precautions

Your best defense against a potential carbon monoxide leak is preventative maintenance. Unlike your kitchen stove, you probably don't notice or check the flame on your furnace on a routine basis. Have your furnace and other gas appliances checked out by a professional once a year. Clean your filters and make your furnace a part of your household safety checklist. Examine the flame on your furnace when you perform your monthly battery test on your fire and carbon monoxide alarms.