What Color Should My Furnace Flame Be?

The burner flames from your natural gas furnace should look blue or almost completely blue. A healthy natural gas furnace flame is characterized by a roaring blue flame with a light blue triangle in its center. There may be a tiny tip of yellow. A blue flame indicates safe and efficient combustion, meaning that the gas is being burned efficiently and not being wasted. Blue flames are hotter and indicate more complete combustion.

If your flame is yellow or orange, or if you see pops of yellow or orange, that is a sign that you have a combustion problem that should be addressed by a professional. Long streaks of any color, such as yellow, orange, or green means your furnace needs adjustment or cleaning from a professional HVAC technician.

Whether it is your gas stove, gas furnace, or any other gas appliance, you always want a blue flame.

If your furnace burner flames are any other color than blue, turn your furnace off and contact a licensed HVAC contractor for service right away!

Want to learn more? Check out this article. You can read other useful articles like this on the MRR blog.