Weil-mclain 386-701-028 Cast Iron Oil Boiler 75000 Btu/h

Product Description

The WEIL-MCLAIN 386-701-028 is a cast iron, oil-fired hydronic boiler rated at 75,000 BTU/h IBR output and 98,000 BTU/h input, delivering an efficiency of 86.4%. Designed specifically for the WTGO-3LR Series 4 line, this unit includes an integrated tankless heater coil, allowing it to serve both space heating and domestic hot water loads from a single appliance. At 560 pounds, this is a commercial-grade residential unit built for long-term durability. Installation and commissioning must be performed by a licensed heating professional in accordance with applicable mechanical and fuel-burning codes.

This boiler is engineered for oil-fired hydronic heating systems in residential applications, with specific fitment noted for Levittown-style homes. The integrated tankless coil eliminates the need for a separate indirect water heater in single-zone and multi-zone hot water baseboard or radiator systems. The 6-inch vent connection accommodates standard oil boiler flue configurations. Supply and return piping connections are sized at 1-1/4 inches and 1-1/2 inches respectively, suiting typical residential hydronic system piping layouts.

Key Features

• 75,000 BTU/h IBR output rating with 98,000 BTU/h input for oil-fired operation
• 86.4% efficiency for oil-fired hydronic systems
• Integrated tankless heater coil for combined space heating and domestic hot water
• Cast iron heat exchanger construction for long-term durability
• 6-inch flue vent connection compatible with standard oil boiler venting
• 20-year heat exchanger warranty and 2-year parts warranty

Compatibility

Designed as an OEM replacement and new-installation unit for WTGO-3LR Series 4 hydronic oil boiler applications, specifically noted for use in Levittown-style residential homes. Supply connection is 1-1/4 inches and return connection is 1-1/2 inches.

Installation Notes

Installation must be performed by a licensed oil heating technician or plumber qualified to work on oil-fired hydronic systems, in compliance with NFPA 31, local mechanical codes, and the manufacturer installation manual. Shut down all electrical power and close the fuel supply valve before servicing. The tankless coil and hydronic connections must be pressure-tested prior to startup. Manufacturers do not accept warranty or technical support requests from homeowners or unlicensed individuals — all inquiries must be initiated by the licensed professional of record.