Find Rebates
Product Selector Find a Contractor Product Literature Technical Literature

K2 Combi

The high efficiency K2 Combi condensing boiler provides more options for home heating and hot water solutions! Designed and built in the USA at U.S. Boiler’s manufacturing facility in Lancaster, PA, the K2 Combi offers the same kind of efficient, reliable performance that you come to expect from U.S. Boiler Company.

Value-priced with Premium Features

  • 95% AFUE with 10:1 turndown
  • Reliable, proven stainless steel heat exchanger technology
  • Flat plate heat exchanger provides superb domestic hot water performance
  • Factory pre-set Sage2.3 Control System, providing out-of-the-box high performance
  • Touch screen diagnostic display with plain-language guidance
  • FREE 5-year parts warranty included
  • Low NOx (meets requirements of South Coast Rule 1146.2)

Extra Built-in Features 

  • Universal boiler vent connections for polypropylene, CPVC/PVC, and flexible stainless steel
  • Outdoor reset and sensor
  • Pre-installed safety relief valve piping

 

Optional K2 Combi Condensing Boiler Accessory: 

usboilersagezonecontrol

 

 

Sage Zone Control Circulator Panel or Valve Panel – Precisely calculates heating demand from different zones and “re-sizes” the boiler for optimum efficiency and whole home comfort.

K2 Firetube

The NEW K2 Firetube condensing boiler is an addition to the K2 high-efficiency series. Joining the K2 Watertube boiler, the K2 Firetube features a stainless steel vertical firetube heat exchanger and is available in six sizes. All models can be wall-hung and feature 5:1 modulation. The boiler’s dimpled, firetube heat exchanger provides lower pressure drop when compared to water-tube heat exchangers of similar capacity.

  • 95% AFUE – high efficiency and low emissions!
  • Six wall hung models; 85, 110, 155, 205, 270 MBH (combi version available for 155 MBH)
  • Field proven, stainless steel fire tube heat heat exchanger
  • Advanced Sage2.2 Boiler Control provides “out-of-the-box” high performance and easy setup
  • FULL SIZE easy access side service panel
  • UNMATCHED High Altitude Performance
  • Versatile top and bottom connections for supply & return (on heating-only boilers)
  • Universal vent connection for CPVC/PVC, polypropylene
  • ENERGY STAR Certified – Efficiency tax credits/rebates may apply
  • 5-year parts warranty

 

Accessories for the K2 Firetube boiler include:

usboilersagezonecontrol

 

 

Sage Zone Control – Precisely calculates heating demand from different zones and “re-sizes” the K2 boiler for optimum efficiency and whole home comfort.

X-C

The X-C is a “value priced” condensing boiler, but that doesn’t mean that it’s “bare-bones” by any stretch. The X-C is a feature-packed condensing boiler for homeowners looking to upgrade to high efficiency at a lower initial price point.

  • Up to 95% AFUE – high efficiency and low emissions!
  • 80 – 180 MBH (5 sizes)
  • 5:1 turndown saves energy
  • ASME “H” stamp-certified stainless steel water tube heat exchanger
    • No welds (less corrosion)
    • Cold burner door design, reduced heat loss, easy to service
  • Factory pre-set, advanced Sage2.2 Boiler Control and LCD display reduce installation time and provides EASY, “out-of-the-box” setup and high efficiency from initial startup.
  • 100% system tested at factory
  • Universal vent connection
  • Outdoor reset and sensor
  • 5-year warranty (parts)

 

PVG

Built on the same platform as the award winning ES2, the PVG blends unmatched performance with long-lasting durability and exclusive energy saving features. Designed as an optimal replacement boiler for millions of homes without existing chimneys, the PVG is designed to vent directly through the side of the house. At the heart of the PVG is one of the most advanced cast iron heat exchangers in the industry, and a well-insulated heavy-duty steel base for longevity.

  • Natural or LP gas
  • High quality boiler control components
  • Time proven cast iron design for durability and reliability
  • Designed for homes without existing chimneys
  • Limited Lifetime Manufacturers Warranty
  • Optional 5 or 10-year parts & limited labor warranty
  • Extended Boiler Warranty Plans are administered by CornerStone United, Inc.

ESC

The Perfect Balance Between Efficiency and Practicality

The ESC gas boiler is a modern, versatile boiler designed to maximize the comfort and efficiency of nearly any heating system. It delivers the perfect balance of energy-saving performance, durability, and features for homes where a chimney-vented boiler is not an option. The ESC features an advanced cast iron heat exchanger, and a well-insulated heavy-duty steel base. Additionally, The ESC features the IQ Control System which not only monitors boiler operation, but also gives the ability to add additional energy saving features to the boiler. By striking a balance between the types of advanced energy saving features typically seen on high-end condensing boilers and the tried-and-true durability of cast iron boilers, the ESC is uniquely able to offer homeowners the best of both worlds!

  • Direct vent (horizontal or vertical) or Power Vent
  • Natural or LP gas
  • Ideal for installations where chimney venting is not possible
  • Industry standard tapping locations fit thousands of existing boiler installations
  • Optional LCD touch screen for system monitoring
  • Outdoor reset available – Increases efficiency by 15 – 20%
  • Reliable, American-made cast iron heat exchanger
  • Lifetime limited warranty
  • Optional 5 or 10-year parts & limited labor warranty
  • Extended Boiler Warranty Plans are administered by CornerStone United, Inc.