Ambient Electric Boiler

Description

The US Boiler Ambient™ Electric Boiler is a high-efficiency, eco-friendly heating solution designed for residential and light commercial applications. Perfect for radiant floor heating, baseboard systems, or other hydronic heating setups, the Ambient™ provides clean, reliable comfort with zero on-site emissions. Its whisper-quiet operation, compact design, and flexible installation options make it ideal for homes looking to replace or upgrade from traditional gas or oil systems. Available in multiple output sizes, the Ambient™ electric boiler delivers dependable performance while supporting a sustainable, energy-efficient future.

Features

• 100% EFFICIENT, ZERO EMISSIONS
• Modern, wall hung residential design
• 54.6, 68.2, & 82 MBH output
• Familiar, proven boiler control
• Easy to install – only 54 lbs.
• UL 834 listed
• Reliable, American-made, steel water tube heat exchanger
• Automatically cycles element usage, extending product life
• Top-mounted elements – service without draining
• Easy interior access
• Flow switch included
• Copper & aluminum wire compatible
• Engineered, manufactured, and supported by industry-leading hydronics experts
• 20-year heat exchanger warranty, 2-year parts warranty

Models

• EB-16 (54.6 BTU)
• EB-20 (68.2 BTU)
• EB-24 (82 BTU)

Documents

• Product Datasheet & Specifications
• Manual
• Quick Start Guide

Alliance LT, Indirect Water Heaters

Description

The Alliance LT works in conjunction with the boiler to provide practically limitless domestic hot water. It has a faster recovery rate than competing tank type electric, gas or oil-fired hot water heaters, insuring plenty of hot water when you need it for your active lifestyle. The Alliance LT is a long-life, corrosion resistant tank, featuring a thermoplastic-lining, making it the perfect choice for any application particularly when water quality, hardness, softness, and chlorides are an issue.

Thermoplastic Lining

The greatest enemies of any water heater are corrosion and rust. The best defense against those enemies is to avoid tank materials that can rust or corrode. By utilizing a proprietary double-bonded thermoplastic tank liner, the Alliance LT can handle even the most aggressive water conditions by continuously replenishing and rebalancing antioxidant levels throughout the storage vessel. This means that the tank won’t rust, and the thermoplastic construction will keep the tank performing over its long service life.

Features

• The Alliance LT is a long-life, corrosion resistant tank, featuring thermoplastic-lining:
• Impervious to water quality variations
• Minimal maintenance required
• No anode rod required
• Advanced TPI thermostat control
• 10-year residential warranty and optional lifetime warranty available!
• Top connections, flexible alignment
• Bolted topside coil access – no tank draining
• Offers lower weight, ease of transport

Models

• AL30LT (30 gallon)
• AL55LT (55 gallon)
• AL80LT (80 gallon)
• AL80CLT (80 gallon commercial)
• AL119CLT (119 gallon commercial)

Documents

• Product Datasheet & Specifications
• Manual
• Submittal Sheet

Alliance SS

Description

The Alliance SS delivers long-lasting, high-performance domestic hot water with its durable stainless steel tank and coil design. Built to work seamlessly with your boiler, it provides fast recovery rates, superior corrosion resistance, and exceptional efficiency. The Alliance SS ensures consistent hot water while minimizing standby heat loss, making it a reliable, low-maintenance solution for residential and light commercial applications.

Features

• Stainless steel tank and coil for maximum durability and corrosion resistance
• High recovery rate for reliable, abundant hot water
• Compatible with most boiler systems for efficient indirect heating
• High-density insulation to minimize standby heat loss
• Low-maintenance design for long service life
• Available in multiple sizes to meet various application needs
• 10/2/1 Limited Manufacturer’s Warranty for added peace of mind

Alpine Commercial

Description

Do you find yourself wishing that the Alpine line included larger sizes so you could heat shopping malls, high schools, and hospitals with it? Wish no more! The Alpine line now includes 399, 500, 600, 700, and 800 MBH models so you can efficiently heat just about any structure. The new models feature the ease of service and installation you’ve come to expect from the Alpine.

In a commercial setting, the big Alpine sizes have a lot to offer where other boilers might fall short. The Alpine’s small footprint allows even the largest models to pass through a standard doorway, and you can stack them two high in small mechanical rooms where lots of capacity may be needed. For simple lead-lag operation, use an RG-45 phone cord to link Alpine units together.

Features

• Up to 97% thermal efficiency
• 399 – 800 MBH (5 sizes)
• Equipped with Sage2.3™ Boiler Control System, includes built-in sequencer for internal staging of up to eight Alpine boilers.
• For use with natural or LP gas
• Unique, patented polypropylene condensate trap with internal cutoff switch prevents damage to heat exchanger from condensate backup
• Less than 20ppm NOx
• Stackable

Models

• ALP399C (399k BTU)
• ALP500C (500k BTU)
• ALP600C (625k BTU)
• ALP700C (725k BTU)
• ALP800C (800k BTU)

Documents

• Product Datasheet & Specifications
• Manual
• Specification Sheet
• I&O Manual
• Universal Gateway LonWorks
• Universal Gateway BACnet

Alta & Alta Combi

Description

It’s the EASIEST boiler you’ll ever install because it’s the MOST ADVANCED boiler ever made.

The Alta and Alta Combi boilers from U.S. Boiler Company are high-efficiency, easy-to-install hydronic heating solutions featuring a self-calibrating gas-adaptive combustion system, a 10:1 turndown ratio, and no-touch five-minute startup. With three-sided service access, an integrated hydro block, and sensor-less temperature reset, they deliver comfort and efficiency with minimal maintenance. 95% AFUE, versatile venting, simple LP conversion, and a 12-year heat exchanger warranty make the Alta series reliable, energy-saving, and ideal for both residential and commercial applications.

Features

• No-touch combustion setup, engineered for five-minute start-up
• Circulator included
  • Grundfos 26-99 (heating-only models)
  • Grundfos UPS-78 Special (combi models)
• Self-diagnostic boiler control
• World-leading stainless steel 316L heat exchanger, corrosion resistant
• Rate-based temperature reset, no outdoor sensor required
  • Assesses environmental conditions, continually adjusting boiler operation for comfort and efficiency
• 2 inputs (T-stat, DHW)
• Warm weather shutdown
• Fuse protected, spare fuses provided
• Three-side unobstructed service access – fast removal of front and side panels
• Simple 2-step natural gas-to-LP conversion with no kits or additional parts required
• Easy lift, wall hanging design (floor stand optional)
• Pre-installed hanging bracket and wall mount kit
• Alta FastPipe (primary/secondary piping) included on combi models, optional on heating models
• Continuous high-efficiency combustion without manual throttle or offset adjustments
• Automatic self-calibration adjusts to variables in environment, component wear, gas and vent pressure
• Low gas pressure capability (2.5 in. wc gas, 8.0 in. wc LP)
• 5-year parts warranty, 12-year limited warranty on heat exchanger
• High altitude (10,100 ft) performance with zero or minimal derate
• Universal vent connection for CPVC, polypropylene
• Boiler flow safety switch (UL353)
• Separated high and low voltage connections
• USB Connect puts complete boiler control in the palm of your hand! Consisting of a free smartphone app (download on App Store or Google Play) and a Bluetooth adapter (sold separately)

Combi Features

• The world’s first 10:1, gas adaptive combi boiler!
• Virtually instantaneous DHW response time
• Selectable economy or comfort/recirculation modes
• DHW temperature maintained under all demand conditions
• 10:1 DHW turndown conserves fuel and extends boiler life
• Integrated DHW hydro block with quick-disconnect flat plate DHW heat exchanger, boiler circulator, 3-way valve, and instantaneous DHW flow sensor
• AltaFastPipe (pre-made primary/secondary manifold)

Models

• ALTAC-136B (combi)
• ALTAC-200 (combi)
• ALTA-080
• ALTA-120B
• ALTA-150
• ALTA180

Accessories

• Floor Stand (P/N: 111576-01)
• USB Connect Bluetooth adapter (P/N: 111667-01)
• DHW Accessory Kit (P/N: 112504-01)
• Primary/Secondary Manifold Kit (heating models only P/N: 111884-01)
• CPVC Starter & PVC Vent Kit (2” P/N: 112270-01, 3″ P/N: 111945-01)
• Service Part Kit (P/N: 111419-01) Expanded kit (P/N: 111707-01)
• LP altitude electrode – ALTA-150, 180, 200 only: (P/N 111745-01)
• OneVent System

Documents

• Product Datasheet & Specifications
• Manual
• Specification Sheet
• I&O Manual
• Combi I&O Manual
• Alta Combi Quick Start Guide
• Alta Heat Only Quick Start Guide
• Submittal
• Alta Service Guide
• SuperPak Parts Kit
• Basic Service Parts Kit
• Floor Stand
• Primary/Secondary Heat Only Manifold
• Extended Features manual
• DHW Piping Kit Instructions
• Universal Gateway LonWorks
• Universal Gateway Bacnet

Aspen

Description

The Aspen High Efficiency Condensing Boiler is designed for exceptional performance, reliability, and versatility. Built with a durable stainless steel firetube heat exchanger and advanced combustion technology, Aspen delivers long-lasting efficiency while reducing emissions. Its sleek exterior design complements proven engineering on the inside, making it a standout choice for both residential and light commercial applications.

Smart Control with USB Connect

The Aspen Boiler can be paired with USB Connect for mobile access and control. With the free app (available on iOS and Android) and a Bluetooth adapter (sold separately), users can monitor and adjust boiler settings directly from their smartphone.

The Aspen High Efficiency Gas Boiler combines advanced technology, energy savings, and ease of use, making it a reliable heating solution for a wide range of applications.

Features

• Up to 96% AFUE with 10:1 turndown ratio for high efficiency and low emissions
• Stainless steel firetube heat exchanger for proven durability
• Advanced Sage2.3™ boiler control for simple setup and optimized performance
• Compatible with Sage Zone Controls for added energy savings and short cycle prevention
• High-altitude ready with little to no de-rating
• Easy access side service panel
• Top and bottom supply/return connection options
• Universal venting compatibility with CPVC/PVC, polypropylene, and stainless steel flex
• Outdoor reset and sensor included
• Pre-piped and wired for low water cutoff installation
• Backed by a 5-year parts warranty

Models

• Six wall-hung models: 85, 110, 155, 205, 270 MBH
• Two light commercial models: 320 & 399 MBH
• Optional floor stands (new)

Documents

• Product Data Sheet & Specifications

Aspen Light Commercial

Description

The Aspen Light Commercial Boiler expands the trusted Aspen line into larger capacities, delivering reliable performance for bigger heating applications. Available in 320 MBH and 399 MBH models, this high-efficiency boiler features a stainless steel firetube heat exchanger and advanced combustion technology to maximize durability, energy savings, and ease of use.

Designed for versatility, the Aspen Lt. Comm. can be wall-mounted or floor-mounted thanks to a pre-installed wall bracket and adjustable feet. Its swappable touch screen display and logo badge offer flexibility for optimal ergonomics and installation.

Smart Connectivity:

With USB Connect, you can take full control of the Aspen Lt. Comm. Boiler from your smartphone. The free mobile app (iOS and Android) paired with a Bluetooth adapter (sold separately) allows for convenient monitoring and adjustments on the go.

The Aspen Light Commercial Boiler combines proven reliability, high efficiency, and user-friendly features—a smart heating solution for schools, multi-family housing, offices, and other light commercial applications.

Features

• Up to 95% Thermal efficiency with 10:1 turndown
• Field-proven, stainless steel fire tube heat exchanger with low pressure drop
• Advanced Sage2.3™ boiler control provides “out-of-the-box” high performance and easy setup
  • Touch screen display simplifies installation, operation, and diagnostics
  • Easily connects to optional Sage Zone Controls for additional energy savings, system optimization, and “short cycle” prevention
  • Configured for lead/lag operation
• High altitude – zero or minimal de-rating reduces the costs of oversizing, field adjustable
• Low NOx•
• Meets requirements of South Coast Rule 1146.2

Valuable Extras

• Universal vent connection for CPVC/PVC, polypropylene, and stainless steel flex
• Split-voltage junction box, fused easy-connect terminals
• Outdoor reset and sensor

Models

• Two light commercial models; 320 & 399 MBH

Documents

• Product Data Sheet & Specifications

Series 2

Description

The Series 2 sets the standard for cast iron gas-fired boilers, combining a durable cast iron heat exchanger, heavy-duty steel base, and reliable controls for long-lasting performance. Trusted for decades, it delivers efficient, low-maintenance comfort and exceptional value for homeowners.

Control Features for Homeowner Comfort and Savings

• Energy-saving “thermal purge” circulates residual heating water before burning fuel
• Domestic hot water priority feature ensures uninterrupted supply of hot water for indirect water heaters

Features

• 84% AFUE efficiency upgrade
  • Meets DOE-2021 government requirements
• 8 sizes available, 38-276 MBH
• Chimney vented
• Standard tapping locations and intuitive electronic controls reduce installation costs
• Direct replacement for thousands of existing boiler installations
• Concealed, protected controls and components
• Lifetime limited warranty

Control Highlights

• INCLUDES pre-installed IDL-1200 low water cut off
• Easy-to-use three button operation and optional adjustments
• Two pump relays for an additional heating zone or indirect water heater

Models

• 202E
• 203E
• 204E
• 205E
• 206E
• 207E
• 208E
• 209E

Documents

• Product Data Sheet & Specifications

X-2 Series

Description

A reliable, full-featured cast iron boiler offering excellent performance and value.

Features

• 38 – 280 MBH (8 sizes)
• All controls concealed inside boiler jacket
  • Integrated boiler control with diagnostics
  • FREE additional pump relay
  • Integral LWCO option requires no piping! (IDL-1200)
• Industry standard tapping locations, allows easy, direct replacement for thousands of existing boiler installations
• American-made cast iron heat exchanger
  • Designed to promote turbulent water flow within the section for efficient heat transfer
• Lifetime limited warranty

Models

• X-202
• X-203
• X-204
• X-205
• X-206
• X-207
• X-208
• X-209

Documents

• Product Data Sheet & Specifications

X-PV

Description

Cast iron design for durable, efficient performance in water heating.

Features

• 70 – 245 MBH (Induced draft, 6 sizes)
• Power vented using indoor combustion air, optional direct vent kit using outdoor sealed combustion air
• Perfect for installations with unusable chimneys
• Includes supply line manifold with relief valve and T/P gauge connections
• Advanced controls, accessible inside boiler jacket
  • Integrated boiler control with diagnostics
  • FREE additional pump relay
  • Integral LWCO included, requires no piping! (IDL-1200)
• American-made cast iron heat exchanger
  • Designed to promote turbulent water flow within the section for efficient heat transfer
• Lifetime limited warranty
• Made in Lancaster, PA, USA

Models

• X-PV3
• X-PV4
• X-PV5
• X-PV6
• X-PV7
• X-PV8

Documents

• Product Data Sheet & Specifications

Ambient Heat Pump

Description

The Ambient Heat Pump is a high-efficiency, zero-emission air-to-water system designed for new or existing hydronic heating setups. Up to 4× more efficient than traditional boilers or electric heat, it provides reliable comfort even in cold climates. The dual fuel controller allows pairing with a boiler for maximum efficiency year-round. Its pre-charged monobloc design and included components—buffer tank, heat exchanger, and pump—make installation simple and fast.

Features

• High efficiency – up to 4× more efficient than boilers or electric resistance heating
• Zero emissions – enables full or partial electrification of heating systems
• Cold climate performance – delivers comfort even in freezing temperatures
• Dual fuel compatibility – pairs with gas, oil, or electric boilers using the Ambient Dual Fuel Controller
• Easy retrofit installation – integrates seamlessly with existing hydronic systems
• Pre-charged monobloc design – simplifies setup and reduces installation time
• Built-in components – includes buffer tank, flat plate heat exchanger, circulator pump, and relays
• Inverter-driven operation – modulates output for improved efficiency and comfort

Models

• HPS-5T60 Package
• HPS-5T60-DF Package

Documents

• Installation & Operation Manual
• Product Datasheet
• Product Warranty
• Application Guide

Alliance LT, Indirect Water Heaters

Description

The Alliance LT works in conjunction with the boiler to provide practically limitless domestic hot water. It has a faster recovery rate than competing tank type electric, gas or oil-fired hot water heaters, insuring plenty of hot water when you need it for your active lifestyle. The Alliance LT is a long-life, corrosion resistant tank, featuring a thermoplastic-lining, making it the perfect choice for any application particularly when water quality, hardness, softness, and chlorides are an issue.

Thermoplastic Lining

The greatest enemies of any water heater are corrosion and rust. The best defense against those enemies is to avoid tank materials that can rust or corrode. By utilizing a proprietary double-bonded thermoplastic tank liner, the Alliance LT can handle even the most aggressive water conditions by continuously replenishing and rebalancing antioxidant levels throughout the storage vessel. This means that the tank won’t rust, and the thermoplastic construction will keep the tank performing over its long service life.

Features

• The Alliance LT is a long-life, corrosion resistant tank, featuring thermoplastic-lining:
• Impervious to water quality variations
• Minimal maintenance required
• No anode rod required
• Advanced TPI thermostat control
• 10-year residential warranty and optional lifetime warranty available!
• Top connections, flexible alignment
• Bolted topside coil access – no tank draining
• Offers lower weight, ease of transport

Models

• AL30LT (30 gallon)
• AL55LT (55 gallon)
• AL80LT (80 gallon)
• AL80CLT (80 gallon commercial)
• AL119CLT (119 gallon commercial)

Documents

• Product Datasheet & Specifications
• Manual
• Submittal Sheet

Alliance Stone Line

Description

The Alliance SL works with your boiler to deliver virtually unlimited hot water with up to 30% energy savings over conventional heaters. Its Hydrastone-lined tank offers superior corrosion resistance, ideal for areas with challenging water quality. Featuring R-16 insulation for minimal heat loss, a high-capacity heating coil, and compatibility with IQ and Sage2.3 control systems for optimized recovery and priority hot water production. Available in five sizes with a 10/2/1 limited warranty and optional lifetime coverage.

Features

• Works with a boiler for virtually unlimited domestic hot water
• Up to 30% energy savings compared to conventional water heaters
• Hydrastone-lined tank for superior corrosion resistance and durability
• R-16 high-density insulation – less than 1°F of temperature loss per hour
• High-capacity heating coil for fast recovery rates
• Compatible with IQ and Sage2.3 Control Systems for hot water priority and faster recovery
• Available in 5 sizes to suit various applications
• 10/2/1 Limited Manufacturer’s Warranty
• Optional Limited Lifetime Warranty for extended protection

Models

• AL27SL (106k BTU)
• AL35SL (106k BTU)
• AL50SL (117k BTU)
• AL70SL (128k BTU)
• AL70CSL (178k BTU)

Documents

• Product Datasheet & Specifications

Alpine Residential

Description

The Alpine condensing boiler delivers top-tier efficiency and performance with its stainless steel heat exchanger and advanced smart controls. It automatically adjusts output based on outdoor temperature for maximum energy savings and comfort. With Sage Zone Control Panels, the Alpine optimizes heating across multiple zones, and USB Connect with Bluetooth and a free app gives you full control from your smartphone. Designed for safe, reliable, and efficient operation, the Alpine is the peak of modern boiler technology.

Features

• High efficiency, condensing boiler – 95% AFUE
• 80 – 399 MBH (6 sizes) 80 – 210 sizes are floor mount or wall hung
• Compact, space-saving modern design
• Industry leading Sage2.3™ Boiler Control System
• Touch screen display for easy user interface to view all system functions
• Available for use with natural or LP gas
• ENERGY STAR Certified – Efficiency tax credits/rebates may apply
• 5-year part replacement warranty (for residential boilers under 300 MBH)

Models

• ALP080B
• ALP105B
• ALP150B
• ALP210B
• ALP285B
• ALP399C

Documents

• Product Data Sheet & Specifications

Baseray Radiator

Description

The Baseray delivers the comfort of traditional cast iron heating in a sleek, low-profile design for water or steam systems. Providing up to five times more radiant heat than finned baseboards, it ensures quiet, even warmth with minimal expansion noise. Durable and timeless, Baseray radiators can be painted to match any room’s décor.

Features

• Low profile, durable cast iron construction
• Even heat distribution
• Durable design
• Quiet operation
• Works with all boilers made by U.S. Boiler Company.

Documents

• Product Data Sheet & Specifications

Citadel

Description

The Citadel delivers twice the power in half the space with its stainless steel heat exchanger and high-efficiency condensing design. Perfect for commercial applications, it provides reliable performance, compact installation, and exceptional energy savings.

Features

• Small unit footprints, zero clearance (Citadel models)
• Stackable/rack-able, doubles MBH/sq.ft.
• 3-in-1 vent connector (Citadel models), multiple venting options
• Up to 300′ of venting (Citadel XL models, 200′ for Citadel models)
• Simplified wiring – separate low/high voltage boards
• CSD-1 built-in (gas train & controls)
• Advanced Concert^TM control system
  • Touchscreen with intuitive navigation and menus
  • Cascade up to 8 boilers
  • Data/event logging
• Modbus connectivity
• Commercial-grade water tube heat exchanger
• Easy access to all boiler service areas
• Complete control panel access: slide out (Citadel models), external (Citadel XL models)

Models

• Citadel: 399-1000 MBH
• Citadel XL: 1250 & 1500 MBH

Documents

• Product Data Sheet & Specifications

Citadel XL

Description

The Citadel XL delivers maximum heating power in a compact, space-saving design. Featuring a stainless steel heat exchanger and ultra-high efficiency, it’s built for demanding commercial applications that require reliability, performance, and scalability.

Features

• Compact footprint with high-capacity output
• Stackable/rackable design to maximize MBH per square foot
• Up to 300′ of venting for flexible installation
• Simplified wiring with separate low- and high-voltage boards
• Built-in CSD-1 compliance (gas train & controls)
• Advanced Concert™ control system with intuitive touchscreen interface
• Cascade capability for up to 8 boilers
• Data and event logging for easy monitoring
• Modbus connectivity for building integration
• Commercial-grade stainless steel water tube heat exchanger
• Easy access to all service areas
• External control panel for convenient operation and maintenance

Models

• Citadel: 399-1000 MBH
• Citadel XL: 1250 & 1500 MBH

Documents

• Product Data Sheet & Specifications

Classic Radiator

Description

The Classic Radiator combines timeless design and modern performance, making it perfect for vintage home restorations or elegant new spaces. Crafted from durable cast iron, it delivers quiet, even heat with excellent heat retention. Available with ornate detailing and optional brass valves, the Classic Radiator adds both style and comfort to any water or steam heating system.

Features

• Available in sizes from 3 to 9 sections
• Can be used in hot water or steam home heating systems
• Superb heat retention
• Rugged construction
• Quiet operation

Documents

• Product Data Sheet & Specifications

EMP

Description

The EMP is a high-efficiency (87%) oil-fired boiler featuring a 3-pass cast iron heat exchanger for superior performance and durability. It comes equipped with valuable extras, including an ECM circulator (Taco or Grundfos) and a return blending manifold that improves water mixing and protects the heat exchanger for long-lasting reliability.

Features

• 87% AFUE, ENERGY STAR® certified
• Five sizes available, 0.60-1.60 GPH
• 3-pass cast iron sectional design
• Chimney or directed vented
• Integral, pre-installed low water cut-off (LWCO)
• Beckett® and Carlin® burner options
• Designed for ease of service
  • Reversible swing-away burner door
  • No target wall
  • Removable rear plates access flue passages
• Lifetime limited warranty
• Easy temperature control
• LWCO – selectable auto or manual reset
• Fuel savings with thermal targeting or traditional outdoor reset capability
• Thermal pre-purge circulation uses latent heat before starting new heat cycle
• Primary circulator control function
• LED active status indicators assist contractors and consumers
  • High temperature, LWCO, economy operation
• Dynamic digital display

Models

• EMP84E
• EMP115E
• EMP140E
• EMP182E
• EMP224E
• EMP280E
• EMP336E

Documents

• Product Data Sheet & Specifications

ES2 Series

Description

The ES2 combines high performance, durability, and energy efficiency with an 85% AFUE rating. Its advanced cast iron heat exchanger and heavy-duty steel base ensure long-lasting reliability. The IQ Boiler Control System allows for optional energy-saving upgrades that can cut fuel use by up to 20%. Ideal for replacing existing chimney-vented boilers.

Features

• Natural or LP gas
• Exclusive IQ Control System platform
• Reliable, American-made cast iron heat exchanger
• Designed for homes with existing chimneys
• Industry standard tapping locations fit thousands of existing boiler installations
• Lifetime limited warranty
• Optional 5 or 10-year parts & limited labor warranty

Models

• ES23
• ES24
• ES25
• ES26
• ES27
• ES28
• ES29

Documents

• Product Data Sheet & Specifications

Independence

Description

The Independence is a durable, gas-fired cast iron boiler for residential steam systems with up to 82% AFUE. Available for natural or LP gas, it features a large water volume, watertight cast iron push nipples, Honeywell controls, vent damper, and insulated steel jacket. PV models offer direct venting for homes without a functional chimney.

Features

• Natural or LP gas on select chimney-vented models
• Rugged cast iron heat exchanger
• Stainless steel burners
• 7 sizes to meet your specific needs
• Optimum venting flexibility
• A limited 10-year heat exchanger warranty, plus a one-year manufacturer’s parts warranty
• Optional 5 or 10-year parts & limited labor warranty

Models

• IN31
• IN41
• IN51
• IN61
• IN71
• IN81
• IN91
• IN3PVNI
• IN4PVNI
• IN5PVNI
• IN6PVNI

Documents

• Product Data Sheet & Specifications

Independence PV

Description

The Independence PV is a direct-vent, gas-fired steam boiler designed for homes without a functional chimney. With up to 82% AFUE, it features durable cast iron sections, watertight cast iron push nipples, and reliable Honeywell controls. Its insulated, powder-coated steel jacket reduces heat loss, while the heavy-duty steel base ensures long-lasting performance. Available for natural or LP gas, the PV offers a dependable, high-efficiency solution for residential steam applications.

Features

• Direct vent (power-vented); no chimney needed
• Cast iron heat exchanger
• Watertight cast iron push nipples
• Stainless steel burners
• Step-opening gas valve (low to high fire)
• Industrial-grade pressuretrol
• Packaged with trim and controls
• Includes vent fan, terminal, and connectors
• Insulated, powder-coated steel jacket
• Natural gas (LP optional)
• Up to 82% AFUE efficiency
• 10-year heat exchanger warranty
• Lifetime nipple leakage warranty

Models

• IN3PVNI
• IN4PVNI
• IN5PVNI
• IN6PVNI

Documents

• Product Data Sheet & Specifications

Megasteam

Description

The MegaSteam is the most efficient cast-iron steam boiler available, achieving 86% AFUE. Its 3-pass cast iron heat exchanger offers superior efficiency and corrosion resistance. Built exclusively for oil-fired residential steam systems, it includes 3″ insulation, a powder-coated steel jacket, and premium components. Backed by a 10-year heat exchanger warranty and an industry-first 5-year water-side corrosion warranty.

Features

• Oil-fired boiler
• Unique 3-pass heat exchanger for exceptional efficiency and steam quality
• Unsurpassed 5-year Warranty against water side corrosion
• Tankless coils are available
• Near boiler piping kit available
• 10-year Limited Warranty on the heat exchanger
• Optional 5 or 10-year parts & limited labor warranty

Models

• MST288
• MST396
• MST513
• MST629
• MST758
• MST892

Documents

• Product Data Sheet & Specifications

MPO-IQ Series

Description

The MPO-IQ delivers top-tier performance, durability, and energy savings. Designed as an ideal replacement for homes with existing chimneys, it achieves up to 87% AFUE—exceeding ENERGY STAR® standards and potentially qualifying for rebates or tax credits. Its advanced 3-pass cast iron heat exchanger and insulated steel jacket ensure lasting efficiency, while the IQ Control System offers optional energy-saving upgrades that can reduce fuel use by up to 20%.

Features

• 87% AFUE
• ENERGY STAR Certified – efficiency tax credits/rebates may apply
• 3-pass cast iron sectional design
• Easy, intelligent IQ Control System
• Outdoor reset available – increases efficiency by 15-20%
• Available direct vent option when a chimney is not available
• Easy installation and servicing
  • Reversible sing away burner door, no target wall/blanket, removable rear plates provide direct access to flue passages
• Limited Lifetime Manufacturers Warranty
• Optional 5 or 10-year parts & limited labor warranty

Models

• MP0-IQ84B
• MP0-IQ115B
• MP0-IQ147B
• MP0-IQ189B
• MP0-IQ231B

Documents

• Product Data Sheet & Specifications

Radiant Radiator

Description

Radiant Radiators are cast iron units designed for water or steam systems and built to fit into wall recesses or enclosures, saving floor space. Their design draws cool air from the bottom, heats it, and releases warm air from the top—providing both radiant and convective heat. With durable cast iron construction, they offer even heat distribution, excellent heat retention, and quiet operation.

Features

• Designed for recesses or enclosures
• Sectional design 4 to 44 sections
• Durable cast iron construction
• Provides radiant and convected heat
• Superior heat retention, even heat distribution
• Quiet operation

Documents

• Product Data Sheet & Specifications

Series 3

Description

The Series 3 gas water boiler combines a durable cast iron heat exchanger, heavy-gauge steel base, and the advanced IQ Control System. With optional energy-saving controls, it can reduce fuel use by up to 20%. Its flexible venting options and modern design make it an efficient, reliable choice for many homes.

Features

• Natural or LP gas
• Time proven cast iron design for durability and reliability
• Optimum venting flexibility for homes with existing chimneys
• Lifetime limited warranty
• Optional 5 or 10-year parts & limited labor warranty

Models

• 303
• 304
• 305
• 306
• 307
• 308
• 309

Documents

• Product Data Sheet & Specifications

Slenderized Radiator

Description

The Slenderized Radiator delivers efficient hot water or steam heat with a durable cast iron design that retains warmth even after the boiler stops running. Available in lengths from 7″ to 84″, it fits nearly any installation and operates quietly for lasting comfort.

Features

• Slim design, durable cast iron construction
• Sectional design, 4 to 48 sections
• Superior heat retention, even heat distribution
• Quiet operation

Documents

• Product Data Sheet & Specifications

Steammax

Description

The SteamMax gas-fired steam boiler sets a new standard for reliability, efficiency, and flexibility. Available in 12 sizes (75–550 MBH), it features a durable cast iron sectional heat exchanger with a 10-year corrosion warranty (residential models under 300 MBH). Designed for easy installation, it offers larger steam chests, smooth steam flow, leak-free metal push nipples, and multiple tapping options for versatile setups.

Features

• 12 models ranging from 75 to 550 MBH
• 10-year waterside corrosion warranty (residential units under 300 MBH)
• Corrosion-resistant cast iron sectional heat exchanger for long life
• Larger steam chest and wider internal waterways for improved steam quality
• No heat transfer pins above water line; added pins below for higher efficiency
• Metal push nipples instead of gaskets for leak-free assembly
• Steam risers in intermediate sections for smooth steam flow
• 2″ supply tappings, 2″ skimming port tapping, and 1.25″ tapping for hydronic zone
• Around 82% AFUE rating with chimney venting
• Pre-cut near-boiler piping kits for models 75–250 MBH
• Rear low-profile draft diverter for tight installations
• Tappings on both ends for piping flexibility
• Available packaged, knock-down, full, split, or sectional assemblies
• Equipped with pressuretrol, probe-type low water cut-off, gauge glass, and 15 PSI relief valve

Models

• STMX075
• STMX100
• STMX125
• STMX150
• STMX175
• STMX200
• STMX250
• STMX299
• STMX350
• STMX399
• STMX450
• STMX500
• STMX550

Documents

• Product Data Sheet & Specifications

V8H Series

Description

The V8H oil-fired boiler combines a durable cast iron heat exchanger with quality components for long-lasting performance. Offering 85% efficiency (upgradeable to 87%), it’s a reliable, easy-to-install replacement for many homes and is available with an optional tankless coil for domestic hot water.

Features

• 85% AFUE or ENERGY STAR certified 87% AFUE available with upgrade kit
• Optional tankless water heater
• Multiple oil burner options for water boilers (Beckett, Carlin, Riello) includes burner cover for quiet operation
• Durable push-nipple connections between boiler sections – will not deteriorate when exposed to petroleum-based antifreeze
• Easy to clean and service – side and stop clean outs provide complete access to flueways
• Full swing-away burner door
• Lifetime limited warranty

Models

• V8H3
• V8H4
• V8H5
• V8H6
• V8H7

Documents

• Product Data Sheet & Specifications