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Hydronic Buffer Tanks

Heat-flo’s Hydronic Buffer Tanks are designed to be used in closed loop heating systems with low-mass boilers, geothermal systems, and chilled water applications. Utilizing our hydronic buffer tanks improves system efficiency and can extend equipment life by reducing the wear and tear on chillers or boilers due to short cycling.


The primary application for the HF-22-BT is to reduce low-mass modulating, condensing boiler short cycling. The high and low left side connections are used for boiler supply and return. The top connection is used to supply the distribution system and the low right connection is the return from the distribution system. If the top connection is piped to the line supplying the air purger and vent, the tank will be self-venting.


The HF-30-BT is designed with 4 – 1 ¼” NPT connections on top, and can be installed under a typical residential mod-con boiler to save space, piping, and labor. Two top connections are connected to the top of the tank, and two top connections direct water to the bottom of the tank via internal stainless steel dip tubes. A ½" connection is in the center of the tank for an air vent.


Our hydronic buffer tanks are built with 5 connections: 2 connections can be piped to the chiller or boiler, and 2 connections can be piped to the distribution system. A fifth connection is available for alternate piping configurations. When configured and piped correctly, Heat-flo hydronic buffer tanks can serve as both a thermal buffer and a hydraulic separator - allowing the heating or cooling source to be hydraulically decoupled from the distribution system.

Quality Design and Construction

  • All stainless steel.
  • Over 2” of insulation, less than 1° / hr. heat loss.
  • Flexible thermoplastic jacket that will not corrode and resists denting.

Easy Installation

  • All pipe connections are on top for a neat, quick, and clean installation.
  • Brass drain and relief valves are factory installed.

Residential and Commercial

  • Models available with 22, 30, 40, 60, 80, and 115 gallon sizes.
  • Banking together 80 and 115 gallon units for large commercial applications.