The all new XTherm – vertical modulating condensing boiler in sizes to 2000 MBTU. XTherm combines time honored high recovery copper fin technology with cutting edge control and combustion advancements. The installer and building owner enjoy broad installation flexibility, easy commissioning, optimum seasonal efficiency, and long term reliability.

Remarkably small footprint saves space for those cramped retrofit projects. Built to last, with industrial grade construction and user friendly serviceability. Extreme burner turndown produces up to 99% efficiency at low fire when it’s most needed. Meets even 2012 LoNOx standards. Now is the time to take a closer look at Raypak’s XTherm.

XTherm products take their jobs seriously. On the outside the muscular powder coated steel cabinet provides clean proportions with a strong, unrivaled weather resistant design. A look on the inside reveals the XTherm’s hybrid heat exchanger system design. Our vertically stacked and robust copper main heat exchanger delivers maximum non-condensing efficiency that works seamlessly with our new state of the art stainless steel commercial grade secondary heat exchanger. Maximum synergy is maintained through out the complete XTherm heat exchange system with Raypak’s proven Cold Water Run System, a proven design approach that ensures the XTherm is built for even the longest days of work, while saving the maximum amount of energy every time it is used.


  • Up to 96% efficiency. Condensing. Cat IV venting required.
  • Cast-iron headers and pumps with copper finned tube primary heat exchanger. Brass headers and cupro-nickel tubes available as options. AB 1953 compliant.
  • Minimum continuous inlet water temperature (50°F).
  • Electronic modulating gas valve and burner, up to 4:1 turn down.
  • Small footprint, less than 11 square feet.
  • On-board diagnostic center, real English, no codes.
  • All models indoor/outdoor certified.
  • Complete cabinet protects all controls and wiring.
  • Certified under SCAQMD rule 1146.2. Meets all Low NOx regulations.
  • Suitable for altitudes up to 10,000 ft. (derate above 5,000 ft.).
  • Primary-secondary piping required.
  • 0-10 VDC Remote set point BMS Interface.
  • 0-10 VDC Direct Drive.
  • Available for natural gas or propane.