What is a common indicator of incomplete combustion in a propane flame?

A yellow or orange flame is a common indicator of incomplete combustion in a propane flame. When propane burns completely, it produces a blue flame, which means that the fuel is burning efficiently and all the propane is reacting with oxygen. However, if the flame is yellow or orange, it suggests that there is an insufficient amount of oxygen for complete combustion, leading to the production of soot and other byproducts.

This incomplete combustion not only signifies inefficiency in fuel usage but also indicates potential safety hazards such as carbon monoxide production. The yellow or orange color is often due to the heating of tiny soot particles that are formed when propane does not burn completely, giving the flame a distinct coloration. Recognizing this indicator is crucial for ensuring the safe and effective operation of propane-burning appliances.