XTherm Condensing Boilers, 2505-4005

The all-new XTherm - vertical modulating condensing boiler, in sizes from 2505 to 4000 MBTU. XTherm combines time-honored high-recovery copper fin technology with cutting-edge control and combustion advancements. The owner can enjoy broad installation flexibility, easy commissioning, and long-term reliability.


Model Number Full Input in
 Flue cat IV Dia.
H7-2505 2,501,000
H7-3505 3,500,000
H7-4005 4,000,000
XTherm Condensing Boilers, 2505-4005


  • 96% efficiency at full fire.  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. CSA Low Lead Certified 0.25% Lead
  • Minimum continuous inlet water temperature (50°F).
  • Electronic modulating gas valve and burner, up to 11 to 1 turn down.
  • On-board diagnostic center, real English, no codes.
  • All models indoor/outdoor construction.
  • Complete cabinet protects all controls and wiring.
  • Certified under BAAQMD rule 7 - Low NOx.
  • 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.
  • VERSA IC® control package with built-in outdoor reset function. 7" touchscreen display, including system sensor, indirect sensor & indirect supply sensor.
  • Cascade control of up to 8 units, no external sequencer required.
  • Cascade in parallel or sequential modulation modes.
  • Modbus® RTU port (RS485).


  • Outdoor air Sensor (B-32)
  • Indirect DHW sensor
  • BACNet IP, BACnet MS/TP, Modbus TCP, N2 Metasys (B-85)
  • Lonworks (B-86)
  • Alarm with 4” Bell (E-5)
  • Low Water Cutoff (F-10)
  • Condensate Neutralizer (Z-12)

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