Keeping your furnace in healthy working is essential for ensuring safe and efficient operation. The flame color indicates whether or not your furnace is burning its fuel safely and efficiently or not.
For homes with furnaces that burn fuel, it’s always a good idea to check out the flame on the burner on a regular basis. The color and behavior of the flames can be a good indicator of the health of your heating system. If you notice that the flames are flickering or if they are any other color than blue, you should shut off your heating system immediately and call a professional.
Flickering flames and incorrect flame colors (anything other than blue) are indications that your furnace is leaking wasting energy and leaking carbon monoxide.
A typical pilot flame is no more than 1″ long. If yours is bigger than that it’s too big. Unless it really big (how long is it?) all it’s doing is using a bit more gas than normal.
Why Does a Blue Flame Indicate More Complete Combustion?
If you remember the Bunsen burner days of your science education, you may recall how different flame colors result from varying amount of oxygen.
By increasing the oxygen supply, you get higher temperatures, less soot, and more complete combustion. When the flame does not receive enough oxygen, you can see the flame color change to a red, orange, or yellow color. You may even notice dark soot rising from the tip of the flame.
Due to the lack of oxygen, the flame is not as hot and although you cannot see, smell, or taste it, more carbon monoxide is released into the air. The coolest flame is a yellow/orange color.
Depending on the gas involved, different amounts of oxygen are required for complete combustion. For instance, propane requires an air-to-gas ratio around 24:1. For natural gas, the ratio is closer to 10:1.
When using a Bunsen burner, you can adjust the color of the flame by opening or closing the air holes. Unfortunately, adjusting furnace flame color is not so easy. Never attempt to adjust furnace flames on your own—always contact a professional.
If you suspect leaks around the furnace unit, stir up a mixture of liquid detergent and water. Paint this mixture on the gas supply line along its connections and valves; the soapy water will bubble at any point where theres a leak. If you find a leak, try tightening the leaking connection with a pipe wrench, but be careful not to over tighten the connection. If the pipe connections or valves still leak, call a professional service person.
The flames on the gas burner should be full and steady, with no sputtering and no trace of yellow. To adjust the flame height on the main burners, call a professional service person. To adjust the height of the pilot flame, turn the flame adjustment screw until the flame is from 1 1/2 to 2 inches (3.8 to 5.1 centimeters) high. The adjustment screw is located near the gas valve on the pilot assembly, if the control has this adjustment feature.
What color should my furnace flame be?
FAQ
What should my gas flame look like?
Should I be able to see flame in my furnace?
How big should the pilot flame be on a gas furnace?
What does a natural gas furnace flame look like?
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.
What is a normal flame in a gas furnace?
The Short Answer Is: A normal flame in a gas furnace is typically blue with a small, steady yellow tip. If the flame is predominantly yellow or flickering excessively, it may suggest problems such as incomplete combustion, gas impurities, or a malfunctioning burner.
What color should a gas furnace flame be?
The burner flames of a properly functioning natural or propane gas furnace should be predominately blue. The flame from each burner should have a “whooshing” sound and have a lighter blue triangle in its center. The flames should be elongated as their heat is directed into the holes or channels of the heat exchanger.
What color should the burner flames be?
Even if this concept is new to you, checking the color of the burner flames might be something that interests you. The burner flames of a properly functioning natural or propane gas furnace should be predominately blue. The flame from each burner should have a “whooshing” sound and have a lighter blue triangle in its center.