Resideo by Honeywell TK300-15 Heating Expansion Tank 2 Gallon 1/2" NPT

The Resideo TK300-15 is a 2-gallon heating expansion tank designed to absorb hot water expansion in closed hydronic heating systems, equipped with a butyl diaphragm to separate air from system water. Pre-pressurized to 12 PSI, this tank keeps fluids circulating and maintains minimum system pressure, preventing pressure relief valve discharge and protecting your heating system components.

Key Features:

• Butyl/EPDM diaphragm - 9 times better than natural rubber
• Deep-drawn steel tank construction for durability
• Factory pre-charged to 12 PSI and 100% tested
• Maximum safe operating pressure of 100 PSI
• Maximum acceptance volume of 1.0 gallon
• 1/2 inch external NPT male connection
• Maximum operating temperature of 240°F (115°C)
• Replaces Watts ETX-15

This expansion tank is compatible with most HVAC applications including boilers, hydronic heating, and water heating systems. The welded steel construction and premium butyl/EPDM diaphragm ensure long-lasting performance and reliable pressure control in residential and light commercial heating applications.