🔍 Key Concepts

• Trace the flow path of makeup water from the initial fill/makeup connection through the expansion tank and into the converter • Understand where dissolved air comes out of solution in a hot-water heating system (cold side vs. heated outlet) • Identify the purpose and best location of an air separator / air eliminator in a closed hot-water loop

💭 Think About

• In the diagram, follow each possible air source mentioned in the options and ask: does that air actually end up in the water side at the outlet of the converter? • Consider at what point the water is hottest and where dissolved gases are most likely to be released, then match that to the location of the air separator • Ask which component in the drawing is responsible for venting or releasing air to atmosphere, and how that relates to the air separator on the converter outlet

✅ Before You Answer

• Verify which line carries makeup/initial fill water into the system and how it connects to the expansion tank and then to the converter • Check whether steam/condensate on the left side can mix with the hot water on the right side or if they are separated by the heat-exchanger tubes • Confirm that the air separator is located on the hottest water outlet from the converter, where air released from solution would be easiest to remove