What the Color of Your Furnace Pilot Light Means

Your pilot light provides a small flame that remains lit inside your furnace to light the gas coming out of the main burner. This pilot light will indicate whether your furnace is receiving the right amount, too much, or too little natural gas, or there is something else burning altogether. Here are the typical colors of a furnace pilot light and what they each mean. When in doubt, call a professional!

Blue = Normal

When your pilot receives the correct amount of natural gas, the flame will be a bright blue color. The largest component of natural gas is methane which burns blue. The tip of the flame may appear orange or yellow, but this is normal. It’s best to check your pilot light from time to time and make sure it remains blue.

Flickering Yellow = Too Much Air

If your pilot light is flickering yellow, there is too much air in the gas line. This could be caused by a damaged tube or loose connection which is allowing air into the gas line, or the furnace’s thermocouple could be damaged. The thermocouple is responsible for opening and closing the main gas line and regulating the amount of gas feeding into the pilot. If it is not letting in enough gas, the flame may burn yellow. Because the two likely culprits that are letting in too much air could also be leaking gas, we recommend shutting off the furnace and calling for a repair.

Bright Orange = Too Much Gas

A bright orange pilot light is the most dangerous colored pilot light. When the flame is burning orange, this means too much gas is feeding the flame. If there is a gas leak from a damaged gas line or damaged thermocouple, the pilot light will not be able to fully burn all the gas and the flame will be orange.

Too much gas going into your furnace could pose a serious health risk by allowing gas to leak into your home through the vents. You will first smell the gas near your furnace and eventually throughout your home. The excess burn-off of the gas can also lead to a buildup of carbon monoxide. If you see a bright orange pilot flame, contact an HVAC contractor immediately.

Any other color?

If your pilot light is any other color like red, green, or some other combination, that means something other than methane—such as tar, oil, rust flakes, or dust—is burning. This could mean harmful chemicals are being pumped into your home along with the warm air your furnace is creating. You will need to shut off the furnace from the breaker box, shut the gas line, and call a professional for a repair.

If you think your pilot light is discolored or you have a question, it is always best to heir on the safe side and call an HVAC professional. Grand Home Services is located in Aurora, Colorado, and provides furnace repair, cleaning, and replacement services throughout the Denver Metro Area. Call us or contact us online today!