Weil-mclain 381-800-879 EG-65 Natural Gas Steam Boiler 250 Mbh Input 157 Mbh Net Ibr 82% Afue

Product Description

The WEIL-MCLAIN 381-800-879 is a residential cast iron natural gas steam boiler designed for reliable, long-term heating performance in both residential and light commercial applications. Built around the proven EG-65 platform, this floor-mounted unit delivers an AGA input rating of 250 MBH and a net IBR rating of 157 MBH, making it a strong choice for high-demand steam heating systems. The boiler carries an AFUE rating of 82 percent, and it comes equipped with an automatic vent damper that helps reduce fuel consumption and improve overall system efficiency. HVAC technicians and heating contractors trust this series for its straightforward serviceability and factory-assembled design, which reduces installation time on the job site. The heat exchanger is constructed from durable cast iron, a material well known for its longevity and resistance to thermal stress in steam applications. Electronic intermittent ignition replaces standing pilots, reducing fuel waste during idle periods. The unit is factory configured for natural gas only and uses a combination gas valve rated for 24 volts. Connections are sized for practical integration into existing steam piping systems, with a 3-inch threaded supply connection and a 2.5-inch threaded return connection. The vent outlet is 8 inches, and the system ships with a horizontal-to-vertical draft hood for flexible venting installation. Safety components are fully integrated and include a 15 PSI ASME relief valve, high-limit pressure control, low water cut-off electrode, spill switch, rollout thermal fuse element, and a steam pressure gauge with syphon and gauge cocks. An insulated extended jacket and electrical junction box are also included from the factory. The boiler measures 29.75 inches in length, 27.625 inches in width, and 33.75 inches in height, with an overall height including the draft hood of 41.875 inches. Water content is 12.6 gallons. This unit is backed by a 10-year limited warranty on the heat exchanger and a 2-year limited warranty on other parts, and it is made in the USA. It meets CSA, ASME H, AHRI, and DOE applicable standards.

• Factory-assembled cast iron section block with insulated extended jacket for reduced field labor
• Automatic vent damper included for improved fuel efficiency and lower operating costs
• Integrated safety controls including ASME relief valve, low water cut-off, spill switch, and rollout thermal fuse

Product Highlights

The Weil-McLain 381-800-879 EG-65 delivers 250 MBH input and 157 MBH net IBR output in a floor-mount cast iron steam boiler package that arrives factory assembled and ready for professional installation. Its automatic vent damper, electronic ignition, and full complement of integrated safety controls make it a dependable solution for residential steam heating replacement or new construction projects.

Product Information

Standard Information

• Brand: WEIL-MCLAIN
• Manufacturer Part Number: 381-800-879

Technical Specifications

• Boiler Type: Steam
• Fuel Type: Natural Gas
• AGA Input Rating: 250 MBH
• DOE Heating Capacity: 209 MBH
• Net IBR Rating: 157 MBH
• AFUE Rating: 82 Percent
• Heat Exchanger Material: Cast Iron
• Ignition Type: Electronic Intermittent
• Burner Type: Stainless Steel, Non-Linting Pilot
• Venting Type: Automatic Vent
• Vent Size: 8 inches
• Supply Connection: 3 inches Threaded
• Return Connection: 2.5 inches Threaded
• Gas Connection: 0.75 inches
• Pressure Rating: 50 PSI
• Relief Valve: 15 PSI ASME Relief Valve Supplied
• Water Content: 12.6 Gallons
• Boiler Dimensions: 29.75 inches Length x 27.625 inches Width x 33.75 inches Height
• Height Including Draft Hood: 41.875 inches
• Mounting Type: Floor Mount
• Applicable Standards: CSA, ASME H, AHRI, DOE
• Warranty: 10 Year Limited (Heat Exchanger), 2 Year Limited (Other Parts)
• Country of Origin: USA