If you have decided it is time to fire up your home's gas furnace for the first time before winter sets in, you may wonder if the heater is working properly. If so, study the color of the pilot's flame, as it can tell you a lot about the health of your furnace.
Steady Blue Flame
After you light your furnace pilot, wait a few minutes to give the gas time to fully push through the line and feed the flame. Then, observe the color and activity of the pilot light.
If you see a steady blue flame that burns evenly, this is exactly what you want to see. This means that the mixture of gas and air are ideal for your furnace and the pilot is burning the way it should. While you may see a glint of yellow or orange, the majority of the flame should be blue.
Flickering Yellow Flame
If you find that your pilot's flame is flickering and is mostly yellow, this means that there is too much air in the gas line. This excessive air could be caused by one or two things.
First, the gas line may have a small leak that is allowing air into the line. This could be caused by a loose connection or damaged tube. As the air flows into the line, the flame is not able to burn enough gas to burn hot and steady.
Second, the furnace's thermocouple may be broken. This part of your furnace regulates the amount of gas that feeds the pilot. If it is no longer working properly, it will not give the flame enough natural gas to burn while allowing air to be sucked into the line.
Bright Orange Flame
The most dangerous colored flame you could see one your pilot light is bright orange. When the flame is burning orange, this means that too much gas is feeding the flame. If the gas is not being properly regulated by the thermocouple or is leaking, the pilot will not be able to fully burn all of the gas.
Too much gas coming through your furnace could pose a serious health risk by allowing gas to leak into your home through the vents. Or, the excess burn-off of the gas can lead to a buildup of carbon monoxide. If you see a bright orange pilot flame, contact an HVAC contractor immediately to have them look at and repair the problem.
If your pilot light's flame is any color except blue, you may have a problem with either your furnace or the gas line. Contact a furnace maintenance and repair service to have them inspect your heating unit and discuss with you anything that needs to be done to ensure that your furnace is operating properly and safely.