Resideo TK300-90 14-Gallon Hydronic Heating Expansion Tank | 1/2″ NPT | 100 PSI | 240°F

Description

The Resideo TK300-90 is a professional-grade expansion tank engineered to protect closed-loop hydronic heating systems from the damaging effects of thermal expansion. As system water heats and expands, the TK300-90 safely absorbs that excess volume, maintaining stable operating pressure and safeguarding boilers, piping, valves, and other critical components from pressure-related failures.

With a generous 14-gallon total capacity, this tank is well-suited for residential and light commercial heating applications where reliable, consistent pressure control is essential. The 1/2 inch NPT connection ensures straightforward integration into standard heating installations, while the heavy-duty steel shell delivers the structural durability demanded by demanding hydronic environments.

At the heart of the TK300-90 is an internal diaphragm that maintains a clean separation between the air charge and system water — eliminating waterlogging, preserving pre-charge pressure, and extending the service life of the tank. Rated for a maximum operating pressure of 100 PSI and temperatures up to 240°F, this tank is built to perform reliably across a wide range of heating system conditions.

Key Features

• 14-gallon total capacity for effective thermal expansion management in hydronic heating systems
• 1/2 inch NPT connection for easy, standard installation
• Rated to 100 PSI maximum operating pressure for dependable system protection
• 240°F maximum temperature rating suitable for high-temperature heating applications
• Internal diaphragm separates air and water to prevent waterlogging and maintain pre-charge integrity
• Absorbs pressure spikes to protect boilers, piping, and system components from damage
• Heavy-duty steel construction engineered for long service life and lasting reliability

Specifications

• Brand: Resideo
• SKU: TK300-90
• Total Capacity: 14 Gallons
• Connection Size: 1/2 Inch NPT
• Maximum Operating Pressure: 100 PSI
• Maximum Temperature: 240°F
• Shell Material: Steel
• Application: Closed-Loop Hydronic Heating Systems