What are indicators of improper combustion in a boiler?

The presence of a yellow flame and high carbon monoxide levels are clear indicators of improper combustion within a boiler. A yellow flame often signifies that there is an incomplete combustion process occurring, which can be attributed to inadequate air supply or poor burner adjustment. This situation can lead not only to inefficient operation but also the production of harmful gases, such as carbon monoxide, which is a byproduct of incomplete combustion. High carbon monoxide levels indicate that there is insufficient oxygen to completely convert the fuel into carbon dioxide and water, raising serious safety and efficiency concerns.

In contrast, dark soot accumulation and low temperatures might suggest issues, but they do not directly and immediately indicate combustion problems as strongly as the yellow flame and carbon monoxide levels. High efficiency numbers and a consistent flame point towards proper functioning, which is the opposite of improper combustion. Lastly, stable pressure and low noise levels typically signal that a boiler is operating correctly and are not indicative of combustion issues. Therefore, the combination of a yellow flame and elevated carbon monoxide levels is a critical sign of improper combustion needing immediate attention.