We updated graphics of the expansion tanks inside InterNACHI’s free, online “How to Inspect HVAC Systems” course at http://education.nachi.org/show.php?course_id=65&element_id=1619.
InterNACHI’s Gallery illustration has also been updated at http://www.nachi.org/gallery/hvac/heating/expansion-tank-water-levels-boiler-internachi.jpg.
