What is produced in significant amounts if combustion is incomplete?

When combustion is incomplete, carbon monoxide is produced in significant amounts. This situation arises when there is not enough oxygen present to allow for the complete conversion of carbon in the fuel into carbon dioxide. Instead of fully oxidizing to carbon dioxide, some of the carbon atoms form carbon monoxide, which is a toxic gas.

In many heating systems, maintaining proper air-to-fuel ratios is crucial for efficient and safe operation. When combustion is efficient, the primary byproduct is carbon dioxide, along with water vapor. However, if the air supply is restricted or the combustion process is not functioning correctly, the formation of carbon monoxide increases, leading to potential safety hazards such as poisoning.

Other byproducts, such as ozone, hydrogen, and carbon dioxide, are not typically associated with incomplete combustion in the same way. Ozone is formed in the atmosphere through photochemical reactions and is not a direct product of incomplete combustion. Hydrogen may be produced during certain reactions, but it's not a significant byproduct of fossil fuel combustion. Carbon dioxide is the expected result of complete combustion, making the production of carbon monoxide the defining characteristic of incomplete combustion.