G2 Gas Fitter Practice Exam 2026 - Free Gas Fitter Practice Questions and Study Guide

When the air shutters on an atmospheric burner are clogged, the burner is unable to receive the proper amount of air necessary for complete combustion of the gas. This results in an improper fuel-to-air ratio, leading to incomplete combustion.

The appearance of a yellow and long flame indicates that there is too much fuel in relation to the amount of air, which typically means that the burner is producing carbon particles due to this incomplete combustion. These carbon particles can cause the flame to appear yellow instead of the desired blue, which indicates efficient and complete combustion. A long yellow flame signifies inadequate air supply, causing the flame to burn less efficiently and creating a larger volume of unburned or partially burned fuel.

Overall, a yellow and long flame is a clear sign of air obstruction in the burner which must be addressed to ensure proper operation and efficiency.