Flexible-Tube Condensing Boiler

Bryan Free Flex condensing boilers title card

The Flexible-Tube Condensing Boiler

Long Life, High Efficiency

The Flexible-Tube design has been in use for more than 100 years.  It has proven to be rugged, reliable and efficient.  The originator of the Flexible-Tube design, Bryan Boilers, in partnership with Thermal Solutions has created the next generation of condensing boilers, with the Free-Flex and Arctic series.

Models are available to fit any commercial/institutional application, with inputs of 1,000 to 6,000MBH.

Why the Flexible-Tube Design?

Because longevity & reliability matters!  Flexible watertubes naturally absorb the intense heat from the burner and expand & contract while holding it’s mechanical seal; providing our Lifetime Shockproof “Seal of Certainty”. Allowing the tubes to flex naturally with thermally induced expansion and contractions, eliminates the concern of relying on a tube-to-tube sheet weld to fight against Mother Nature.  We expect the life cycle to be similar to other Bryan Flexible-Tube designs, 30-40 years plus!

Efficiency. The flexible-tube design provides for a very generous heating surface allowing for high efficiencies, during a wide range of operating conditions.  The boilers are all rated at 95% AHRI Thermal Efficiency.

Serviceability. All typical service points are accessible through either the front control cabinet or by removing the side panels.  The tubes are mechanical sealed into the header, no welding.  This allows for a field-repairable design – in most other condensing designs, complete replacement of the heat exchanger is often the only option.

Footprint and easy installations. All connections are on the top of the boiler, giving a small installed footprint comparable to other condensing designs.  This mechanical design also allows for the boilers to be available in a Knockdown configuration, easing access into existing, hard to get to, or tight spaces.

Low pressure drop design.  Low waterside pressure drop plus the ability to easily accept large delta-T’s means the boilers are ideal for any piping topology; Primary-Secondary, Variable Primary, Variable Primary-Secondary and Variable Primary-Variable Secondary. Using Eco-Propel variable speed pump control, the boiler can manage its primary pump to best match the current load conditions, enabling savings on fuel and electricity.


  • Concert Boiler Control
  • Standard Features
  • 7” Color Touch Screen Display
  • Intuitive Navigation
  • Quick and Easy Setup Menu
  • Single Boiler Control
  • Multiple Boiler Control Sequencer
  • Communication Connects Up to 8 Boilers
  • Building Management System Interface; Modbus, LonWorks, BACnet
  • Unmatched Archives – 4 Months of Historical Operational Data
  • USB Port for Data Sharing
  • Self-Guiding Diagnostics – Industry-Leading Fault Identification & Correction Steps
  • Outdoor Air Reset
  • High & Low Voltage Fused Printed Circuit Boards (just replace fuse, not boards)
  • Built-in Brown-out Protection



  • 1,500 – 6,000 MBH
  • 95% AHRI Certified
  • Up to 99% Maximum Efficiency
  • Lifetime Shockproof Warranty
  • Flexible Watertube Heat Exchanger
  • Available Fully Packaged or Knockdown Construction
  • Primary/Secondary, Full Flow and Variable Flow Systems
  • Concert Integrated Control Platform
  • Touchscreen Programming & Diagnostics
  • Modbus, LonWorks, BACnet BMS Integration
  • Low NOx & CO
  • Superior Durability
  • Easy Installation & Maintenance

 Additional Bryan & Thermal Solution Products:

  • DR, AB, RV, RW, CLM and EB Series; Flexible-Tube Steam and Hot Water: 250 – 17,640MBH
  • Apex Series; Condensing Boiler, Stainless Watertube, 399 – 800MBH
  • Evolution Series; Condensing and Non-Condensing Boilers, Copper Fin & Stainless, 750 – 3,000MBH
  • Solaris; Hot Water Boiler, Copper Fin, 500 – 1,250MBH
  • Storage Tanks; Glass Lined
  • Skid Mounted Pacakges
  • Steam Boiler Accessory Equipment; Feed Systems, Deaerators, Blowdown Equipment and more.

For a more complete product list with additional details, please visit:

https://www.bryanboilers.com and https://www.thermalsolutions.com

To learn more about any of our exciting product lines, contact us today at:

https://www.wcrouse.com/contact/, or 336-299-3035