Question 438General Subjects - Assistant Engineer

The correct answer is C. The air separator removes the entrained air introduced with the makeup water at the expansion tank and ultimately released by the heating process within the converter. This is because the makeup water added to the system to replenish any losses will contain dissolved air. As the water is heated in the converter, this air is released and needs to be removed by the air separator to prevent air pockets from forming in the system. The other options are incorrect because they do not accurately describe the purpose of the air separator in a hot water heating system. The air separator is not removing air introduced by the steam, the heating process, or the zone return lines.