Product Description
The Weil-McLain 381-359-363 is a CGI-5 Series 5 cast iron hot water boiler designed for residential and light commercial hydronic heating systems. It runs on natural gas and uses spark ignition for reliable, consistent startups without a standing pilot light. This boiler delivers 88,000 BTU of heating output and carries a BTU input rating of 119,000, giving it a steady and efficient heat transfer profile suited for forced hot water systems. The unit achieves 84% thermal efficiency and is rated for operation at altitudes up to 4,500 feet, making it a solid choice for a wide range of installation locations. Cast iron construction is the defining feature of the CGI-5 heat exchanger. Cast iron holds heat well, resists corrosion over decades of use, and stands up to the demands of high-cycle hydronic systems. That durability is reflected in the 20-year heat exchanger warranty, with a 2-year warranty covering parts. The boiler connects to the water supply through a 1-inch water connection and vents through a 3-inch power vent configuration, allowing flexible placement in mechanical rooms where direct chimney access may not be available. The gas supply connection is 1/2 inch, which is standard for natural gas appliances in this BTU range. The IBR rating of 89,000 BTU and DOE heating capacity rating of 102,000 BTU reflect independently verified performance standards used by HVAC professionals when sizing hydronic systems. The CGI-5 Series 5 is a hydronic water boiler, meaning it heats water that circulates through radiators, baseboard heaters, or radiant floor systems. The unit is compatible with a 007e circulator for proper system integration. Physical dimensions are 16 inches wide, 28-3/8 inches tall, and 23-1/4 inches deep. This boiler must be installed, commissioned, and serviced by a licensed HVAC professional in accordance with all applicable codes and manufacturer instructions.
- Cast iron heat exchanger with 20-year warranty for long-term durability in hydronic heating applications
- Spark ignition system eliminates standing pilot light, improving reliability and reducing gas consumption during standby
- Power vent configuration provides installation flexibility in mechanical rooms without direct chimney access
Product Highlights
The Weil-McLain CGI-5 Series 5 cast iron boiler combines proven hydronic heating performance with a durable cast iron heat exchanger and a 20-year warranty, making it a dependable choice for licensed HVAC professionals installing or replacing natural gas hot water boilers.
Product Information
Standard Information
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Brand: WEIL-MCLAIN
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Manufacturer Part Number: 381-359-363
Technical Specifications
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Product Type: Boiler
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Boiler Type: Standard
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System Type: Hydronic (Water)
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Fuel Type: Natural Gas
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Ignition Type: Spark Ignition
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Vent Type: Power Vent
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BTU Output: 88,000 BTU
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BTU Input: 119,000 BTU
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IBR Rating: 89,000 BTU
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DOE Rating: 102,000 BTU
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Efficiency: 84%
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Application: Heating
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Water Connection: 1 inches
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Gas Connection: 1/2 inches
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Vent Size: 3 inches
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Width: 16 inches
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Height: 28-3/8 inches
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Depth: 23-1/4 inches
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Max Altitude: 4,500 feet
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Features: 007e Circulator Compatible
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Warranty: 20 Year (Heat Exchanger) / 2 Year (Parts)
