How high must an open-type expansion tank be located above the highest heating element?

An open-type expansion tank must be installed at a height that ensures it functions correctly by allowing the system to accommodate thermal expansion and prevent excessive pressure buildup. According to the International Mechanical Code, the requirement is that such a tank be positioned at least 4 feet above the highest heating element.

This height is critical because it helps maintain an appropriate water level in the tank and ensures that the water expands successfully into the tank without causing pressure issues in the heating system. If the elevation is insufficient, thermal expansion could lead to a system malfunction or failure due to pressure buildup or other operational issues. Thus, placing the expansion tank at least 4 feet above the heating element is essential for safe and efficient operation.