Weil-mclain 383-900-178 Gas Boiler 121000 Btu Natural Gas

Product Description

The WEIL-MCLAIN 383-900-178 is a high-efficiency condensing natural gas boiler from the ECO Tec Series 2 line, engineered for hydronic heating applications. Rated at 150,000 BTU input with a DOE output rating of 139,000 BTU and an IBR net rating of 121,000 BTU, this unit delivers 95% thermal efficiency — meeting the performance expectations of commercial and residential hydronic systems. Direct vent configuration uses PVC flue material with 3-inch or 2-inch vent sizing. Licensed heating professionals are required for installation, commissioning, and any service work on this equipment.

This boiler is designed for forced hot water hydronic heating systems in residential and light commercial settings. The ECO Tec Series 2 platform targets applications where high-efficiency condensing operation is required to meet energy codes or owner efficiency goals. Its direct vent design allows combustion air to be drawn from outside the building, making it suitable for tight construction and sealed mechanical rooms. Installation is performed by licensed plumbers, pipefitters, or heating contractors.

Key Features

• 95% thermal efficiency — condensing operation for maximum fuel utilization
• 150,000 BTU input with 121,000 BTU IBR net output rating
• DOE heating capacity rated at 139,000 BTU
• Direct vent PVC flue system with 3-inch or 2-inch vent sizing
• Hydronic water-based system type for radiant and baseboard distribution
• Natural gas fuel — ECO Tec Series 2 platform

Compatibility

Designed as an OEM-style natural gas condensing boiler replacement or new installation unit for hydronic heating systems requiring high-efficiency direct vent operation.

Installation Notes

Installation, commissioning, and service must be performed by a licensed plumber, pipefitter, or heating contractor in accordance with manufacturer instructions and applicable local codes including the IFGC and IPC. Shut off all gas and electrical supplies to the system before beginning any work. PVC vent piping must be installed per manufacturer guidelines and local building codes — do not substitute vent materials without verifying compatibility with the appliance rating. Manufacturers do not accept warranty or technical support requests from unlicensed individuals; all warranty and technical inquiries must be submitted by the licensed professional responsible for the installation.