ThermoFlo Watertube Boiler

High & Low Pressure Steam - High & Low Temp Hot Water - Thermal Fluid - Water Glycol

The Indeck ThermoFlo Watertube Boiler is a two-drum multipass watertube boiler designed to optimize heat transfer and ensure exceptional performance. With five longitudinal gas passes strategically separated by tangent waterwall tubes, this boiler guarantees maximum efficiency and heat exchange.

To enhance its durability and integrity, the tubes of the ThermoFlo Watertube Boiler can be securely attached to the drums using either welded or press-fit methods. Each tube is equipped with a ferrule attachment welded to its end, ensuring a robust and reliable connection.

The versatility of the ThermoFlo Watertube Boiler makes it an ideal choice for boiler replacement projects. Its innovative design allows the entire unit to be supplied as a convenient field assembly kit, simplifying transportation and minimizing logistical challenges. When faced with limited access to the boiler room, our solution truly shines, as the ThermoFlo Watertube Boiler can be easily erected on-site.

We understand the importance of seamless installation and operational efficiency, and the ThermoFlo Watertube Boiler is designed with these factors in mind. With its field assembly kit and straightforward erection process, you can overcome any obstacles related to boiler room access without compromising performance or reliability.

About ThermoFlo


Convenient sizes from 15 BHP to 800 BHP output


Standard 160 PSIG to 200 PSIG or higher as specified


Natural gas, low BTU gas, Oil or Combination Gas/Oil


ASME, National Board, UL, ULC and as specified


Compliance with all current low NOx regulations

ThermoFlo Watertube Boiler


Emission Standards

The boiler’s design is optimized for low NOx applications due to its generous furnace volume and low heat release rates. By utilizing refractory materials sparingly, this design achieves excellent performance. Rigorous testing has confirmed that even with conventional standard burner equipment, the boiler’s NOx emissions remain below the stringent levels set by current regulations.

Symmetrical Design

Low Maintenance


The ThermoFlo Watertube Boiler is ideal for boiler replacement projects. The entire unit can be supplied as a field assembly kit and is easily erected on site when boiler room access is a problem. As the entire boiler assembly is bolted and the tubes can utilize a drive fit there are no requirements for site welding or pressure vessel welding certificates.

Additional Balanced Watertube Designs

Indeck Boiler Models