Resideo by Honeywell TX-12 Expansion Tank 4.4 Gallon 3/4 Inch Connection

The Resideo by Honeywell TX-12 is a 4.4-gallon thermal expansion tank designed to protect potable water heating systems from excessive pressure buildup. As water heaters heat water, thermal expansion occurs, which can cause dangerous pressure increases in closed plumbing systems. This expansion tank provides a safe chamber for the expanded water volume, preventing relief valve discharge and extending the life of the water heater and plumbing components.

Key Features:

• 4.4-gallon capacity suitable for residential water heating systems up to 50 gallons
• 3/4-inch NPT threaded connection for standard plumbing installations
• Durable steel construction with factory-charged air cushion
• Butyl diaphragm separates air and water chambers to prevent waterlogging
• Pre-pressurized to 40 PSI for typical residential applications
• Complies with plumbing codes requiring thermal expansion control in closed systems

The TX-12 installs on the cold water supply line near the water heater and requires no maintenance under normal operating conditions. This tank is essential in homes with check valves, pressure-reducing valves, or backflow preventers that create a closed plumbing system. Proper thermal expansion control protects against pipe damage, fitting leaks, and premature water heater failure.