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.

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

Local Savings

  • 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
  • Cascade control of up to 8 units, no external sequencer required..
  • 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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