What is a sign of proper combustion in gas appliances?

A sign of proper combustion in gas appliances is the absence of discoloration from combustion. This indicates that the fuel is burning efficiently and completely, meaning the combustion process is producing primarily carbon dioxide and water vapor, rather than unburned fuel or harmful byproducts. In a well-functioning gas appliance, when the flame burns cleanly, it should have a blue color, which signifies that the combustion is occurring efficiently.

Discoloration can suggest incomplete combustion, leading to the production of carbon monoxide and other contaminants that can be harmful to both health and the appliance's lifespan. Proper combustion should result in minimal byproducts, which is why the presence of discoloration would indicate an issue with the combustion process. Thus, maintaining clean combustion is crucial for safety and efficiency in gas appliances.