XTherm® Condensing Water Heaters, 2505-4005

The all-new XTherm - vertical modulating condensing heater in sizes to 4000 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, and long term reliability.

XTherm® Condensing Water Heaters, 2505-4005


Model Number Full Input in
 Flue cat IV Dia.
WH7-2505 2501,000
WH7-3505 3,500,000
WH7-4005 4,000,000

  • 97% efficiency.  Condensing, Cat IV venting required
  • Brass headers with copper finned-tube primary heat exchanger.  Cupro-nickel tubes available as options.  CSA Low Lead Certified 5.25% lead
  • Minimum continuous inlet water temperature (50°F)
  • Electronic modulating gas valve and burner, up to 12.5:1 turndown
  • On-board diagnostic center, real English, no codes
  • All models indoor/outdoor construction
  • Complete cabinet protects all controls and wiring
  • Certified under BAA!MD rule 7 - LowNOx
  • 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
  • Built-in cascade function for up to 4 heaters
  • Modbus® RTU port (RS485)


  • 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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