WGO-6R - 149,000 BTU Output Cast Iron Gold Oil Boiler - Series 4 (Burner is not included)

Weil-McLain WGO-6R Gold Series – High-Efficiency Oil-Fired Water Boiler for Hydronic Systems

The Weil-McLain WGO-6R is an oil-fired water boiler engineered for high-performance hydronic heating in larger residential or light commercial buildings. Built with Weil-McLain’s cast iron sectional design and a recessed target wall, the WGO-6R is designed to handle the thermal demands of closed-loop systems with minimal service interruptions and long service life.

This model is part of the WGO Gold Series, which features factory-installed components to streamline installation, including a circulator, service switch, and terminal strip. The WGO-6R is a dedicated water-only model and does not include a tankless coil, allowing for simplified piping and increased efficiency in space heating applications.

Key Performance Features

• Output Capacity: 149,000 BTU/hr DOE heating capacity
• Cast Iron Construction: ASME-rated heat exchanger sections offer thermal mass and long-term durability
• Venting Flexibility: Rear or top flue outlet (7") allows adaptation to site-specific chimney configurations
• Service-Friendly Design: Hinged burner door and open top access simplify maintenance and inspection
• Factory-Installed Components: Circulator pump, wiring harness, and service switch are pre-wired for faster installation

System Design Considerations

• Combustion Type: Oil-fired, atmospheric draft
• Flue Collector: Aluminized steel flue collector with integral hood improves corrosion resistance
• Target Wall: Recessed firebrick protects from flue brush damage and extends service life
• Working Pressure: Rated at 50 PSI max; pressure-tested for reliability
• Water Content: 9.7 gallons

Installation & Compliance

The WGO-6R is designed for closed-loop hot water heating systems and should be installed in accordance with local plumbing, fuel oil, and mechanical codes. A barometric damper and appropriate draft control are required for proper flue performance. This unit requires a professional installation and is not suitable for DIY applications due to fuel oil handling and venting complexity.

Product Specifications

• DOE Heating Capacity: 149,000 BTU/hr
• Net I=B=R Rating: 129,000 BTU/hr
• No. of Sections: 6
• Dimensions: Approx. 32.5" H x 21.25" W x 33" D
• Weight: 540 lbs (approx., assembled)
• Flue Outlet: 7" dia. (top or rear)
• Burner Opening: 4-5/8"

Field Applications

• Retrofits in oil-heated homes where tankless coils are not needed
• Hydronic baseboard, panel radiator, or radiant floor systems
• Small commercial zones with dedicated oil-fired space heating