Condensing Hydronic Boilers

  • Input Capacity (MBH): 6000, 10000, 12000
  • Steam or Hot Water: Hot Water
  • Vessel Design: Firetube
  • Number of Passes: 2
  • Design Temperature (deg F): 210
  • Fuel: Natural Gas, #2 oil, Propane, Combination Firing
  • Emissions (ppm NOx): <30 standard, lower emissions optional
  • AHRI Thermal Efficiency (%): 96.3
  • AHRI Combustion Efficiency (%): 95.6

  • Fully condensing high-mass firetube boiler
  • 316L stainless steel construction
  • Utilizes proprietary "EX" firetube design
  • Dual fuel condensing - gas with #2 oil back-up
  • Gas only condensing
  • Robust, industrial design
  • 6000, 10,000, 12,000 MBH capacities
  • Standard less than 30 ppm NOx (natural gas)
  • Standard less than 60 ppm NOx (#2 fuel oil)


Designed for use in variable flow primary systems, the SwitchFire® boiler is a high-mass, fully condensing firetube boiler constructed of 316L stainless steel. The boiler is designed to handle variable flow pumping with a low waterside pressure drop and large water volume. With its dual fuel (natural gas and #2 fuel oil back-up) capabilities, as well as a variety of other fuels, the SwitchFire® is well suited for healthcare applications and other facilities requiring redundancy with alternate fuels. With its Weishaupt burner and controls, the SwitchFire offers industry leading efficiencies and performance with both natural gas and #2 fuel oil firing.


  • Product Overview
  • Related Resources
  • Applications
  • Fully condensing with up to 98% efficiency 
  • 5:1 fully modulating turndown
  • Sub 30 ppm NOx standard, lower emissions available
  • No minimum return water temperature for maximum efficiency 
  • Dual fuel and gas only capabilities mean the SwitchFire® is well suited to a variety of applications


The SwitchFire® integrates Cleaver-Brooks leading heat exchanger, featuring stainless steel EX rifled tubes, with proven burner and controls technology for a robust, reliable, efficient product. The SwitchFire’s burner design allows for efficient, low emissions operation when firing both gaseous fuels and #2 oil.


Controls Strategies for Maximizing Condensing Boiler System Efficiency →

Learn basic boiler control strategies and staging methods to maximize boiler operating efficiencies.

Why Ultra-High Turndown Is Bad For Hydronic Condensing Boilers →

Learn about optimized system efficiency, why matching boiler and pump turndown is critical to maintain the delta T and maximize efficiency.

  • Healthcare Facilities
  • Building Heating
  • Manufacturing Processes
  • Colleges & Universities