XTherm Condensing Water Heaters, 2505-4005

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.


  • 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)
  • The XTherm combines the proven capability of a finned copper or cupronickel tube heat exchanger with a stainless steel condensing heat exchanger to maximize thermal efficiency and provide long-term reliability. 

    • 97% thermal efficiency at full rate 
    • 100% factory fire-tested 
    • VERSA IC® modulating controller with 7" color touchscreen display 
    • Raymote™ IoT connectivity standard 
    • Full electronic modulation, 60% min fire under normal conditions 
    • Full safety diagnostics with history 
    • Status display lights 
    • Cascade up to 8 heaters - no external sequencer required 
    • Modbus RTU BMS port CSA low-lead certified ≤ .25% lead 
    • Maximum outlet water temperature: 200ºF (93ºC) 
    • Maximum tank set-point temperature: 160ºF (71ºC) 
    • Minimum inlet water temperature: 50ºF (10ºC) 
    • Limited 25-year thermal shock warranty 
    • Limited 5-year copper/10-year cupronickel primary heat exchanger warranty 
    • Limited 10-year stainless steel condensing heat exchanger warranty 
    • SCAQMD Rule 1146.2 certified, Ultra-Low NOx < 20 PPM 
    • Must be used in conjunction with a storage tank for proper operation 
    • Proudly assembled in the USA
Technical specification
  • Unique ref.XTherm-Condensing-Water-Heaters-2505-4005
  • Collection setBoilers & Water Heaters
  • CollectionDomestic Hot Water Heaters
  • TypeObject (single object)
  • Date of publishing2020-10-01
  • Edition number1
  • Designed inUnited States
  • Manufactured inUnited States
  • BIMobject CategoryHVAC - Water heaters
  • IFC classificationHeat Exchanger
  • UNSPSC nameDomestic water heaters
  • UNSPSC code40101825
  • Uniclass 2015 CodePr_60_60_96
  • Uniclass 2015 DescriptionWater heaters
  • CSI MasterFormat 2014 Code22 34 00
  • CSI MasterFormat 2014 TitleFuel-Fired Domestic Water Heaters
  • OmniClass TitleHot Water Heaters
  • OmniClass Number23-31 29 00
  • CSI UniFormat II CodeD3090
  • CSI UniFormat II TitleOther HVAC Systems & Equipment

Region availability

North America
United States