• Excelsior EXB-Front View

    Excelsior EXB-Front View

Excelsior EXB Series

EXB Series

The Dunkirk Excelsior EXB High Efficiency 3-Pass oil boiler features a more compact design that it's predecessor for an even easier installation. The unit features a High Limit Control with LED Display, easy to program Dial Settings, Boiler Water Temperature Reset and Low Water Cut Off functionality.

The EXB is easy to service with wide flue ways, flexible oil line, dual hinged swing door with left or right mount option, site glass and a test port. The low mass design is eco-friendly too, with AFUEs as high as 87% and low standby losses.


  • Efficiency:  Up to 87% AFUE, ENERGY STAR® Certified (EXB4075, EXB5100, EXB6130, EXB7165)
  • Capacity: Multiple Firing Rates
    • 4 Section - 105, 126 MBH
    • 5 Section - 140 MBH
    • 6 Section - 182 MBH
    • 7 Section - 231 MBH
  • Heat Exchanger: Cast Iron
  • Combustion: Atmospheric
  • Venting: Vertical or Direct Vent
  • Boiler Type: Hot Water
  • Boiler Control Module: Hydrolevel Fuel Smart HydroStat Control - combination Low Water Cut Off with boiler temperature reset and circulator control.
  • User Display Interface: Digital display with easy to set dial-type limit settings.
  • Heat Exchanger: High efficiency, cast iron, 3-pass design with reversible swing door and target wall. Efficiency baffles/liner by model.
  • Combustion: Oil burner with protective cover, flexible oil line.
  • Electrical: Wiring harness with Molex connectors. Burner electrical disconnect.
  • Other
    • Temperature/pressure gauge
    • 3/4" ASME relief valve
    • Drain valve
    • Textured painted steel jacket


  • Beckett or Riello Burner
  • Manual Reset High Limit with plug-in Molex connector
  • Direct Vent


  • Easy to Service
  • Flexible oil line combined with easy access heat exchanger with dual hinge swing door (right or left mount option) 
  • Wide flue-ways for easy cleaning 
  • Site glass for flame observation 
  • Removable 1/4" test port for draft overfire reading

Documents / Resources

Current Documents
Archived Documents


User Manual

Installation & Operation Manual

Parts Lists


Venting Addendum

Engineering Documents / Resources

Parts Manual

Product Bulletin

Product Testimonials

  • Very pleased with the work and the way it performs.

    Stephen Almy
    Rockville, RI
  • Highly recommended by contractor and a great warranty.

    Jody Rupert
    Nuremberg, PA
  • So far it is quiet and efficent.

    Glenn Barnes
    Dayton, NY
  • I would recommend this product. This is not my 1st dunkirk boiler. I had one in a previous home that i owned.  The contractor (Oms Heating & Plumbing) that installed boiler, I would highly recommend. He did a very neat and professional job

    Paul Ott
    Wappingers, NY
  • Compact size, excellent price, functional.