LGB Gas Boiler Weil-McLain – Commercial Boiler

Request a Price

  • Short draw rods permit faster, easier assembly of boiler sections
  • Includes factory-assembled base and burners, and simplified piping for quick and easy installation
  • Compact design allows for more piping and venting headroom
  • The highest efficiency commercial cast iron atmospheric gas boiler available by Weil-McLain
  • Built-in air separator diverts air to the expansion tank
  • Gas natural draft water and steam boiler with cast iron sections
SKU: LGB Category:
Financing Available Apply now with Synchrony


Over the last 130 years, Weil-McLain has built a reputation of designing some of the most reliable boilers in the marketplace. Their dedication to producing lasting heating solutions is seen in every boiler they make. The LGB brings Weil-McLain reliability to the largest of applications. LGB Gas Boiler Weil-McLain is available for natural gas or liquid propane installations in either steam or hot water. There are 20 sizes available, and that is just the beginning of customization. Weil-McLain knows that no two massive applications are the same, so they have developed a variety of control packages for the LGB. To keep installation and piping simple, Weil-McLain has ensured that even the largest LGB only requires two risers. When it comes to large applications, the LGB brings versatility, efficiency, and reliability together in a package that fits your application.


LGB Gas Boiler Weil-McLain Features:

  • Factory-assembled base and burners reduce installation time.
  • Simplified piping. The largest LGB™ steam boiler requires only two risers.
  • Built-in air separator in water boilers. Air is diverted to the expansion tank through a 1” tapping next to supply outlet.
  • Steel jackets with durable powdercoat finish in WeilMcLain® blue completely insulated…designed for fast installation.
  • 10 Year Limited Heat Exchanger Warranty. Covers cast iron sections.
  • 85.1% combustion efficiency saves energy. The LGB™ is the highest efficiency cast iron atmospheric gas boiler available.
  • Cast iron sections for corrosion resistance and long life.
  • Compact design saves valuable space…only 50⅜” high, allowing more headroom for piping and venting.
  • Patented section sealing method, short draw rods and sealing rope section speed assembly to reduce installation time.
  • Extra-large 9” top port opening forms an internal header for better water circulation. Large steaming area assures rapid generation of dry steam.
  • AGA design certified for natural and propoane gas. Ratings certified by Air-Conditioning, Heating and Refrigeration Institute (AHRI) for natural and propane gas.


Durable, Efficient Construction
Corrosion-resistant, cast-iron boiler sections mean that your LGB will withstand the rigors of even the most trying applications. The sections also contain heat pin studs which improve heat transfer and efficiency by diverting hot gases.

Efficiency-Boosting Insulation
Heat retention is critical to energy efficiency. Heat leakage represents energy use without any comfort gains. An extended, insulated steel jacket prevents heat from escaping the LGB and improves the efficiency.

Captured Seals
Elastomer rings seal the sections’ ports better than traditional metal push nipples. The elastomer expands and contracts with the section, maintaining a watertight seal in all conditions.

Easy Maintenance
Keeping the LGB clean and running efficiently is a breeze. The rear jacket and steel cleanout plates are easily removable, providing quick access to the flue passages.

Jumbo Top Port
The top port opening of the LGB Gas Boiler Weil-McLain is 9 and forms an internal header within the unit. This improves water circulation

Jumbo Steaming Area
Weil-McLain believes you should never have to wait for dry steam. The LGB Gas Boiler features an extra-large steaming area for express steam generation and ideal comfort.

Additional information