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Effortless comfort, Maximum Efficiency
LGB High Efficiency Series 3 Commercial Gas Boiler

The Weil-McLain LGB Series 3 Commercial Gas Boiler is a durable, high-performance solution for light commercial and institutional heating needs. Offering 14 models with up to 84% thermal efficiency, it features a rugged cast iron design, easy installation options, and user-friendly controls. Ideal for schools, municipal buildings, and large residences, the LGB Series 3 delivers reliable and efficient heating.

Features
big on warmth, low on energy use
Engineered for comfort, designed for efficiency
Certified ENERGY STAR® and heat pump ready, this high-efficiency boiler delivers powerful, eco-friendly performance while keeping energy costs low.


Technical Specs
MODEL | INPUT (BTU/HR) | MINIMUM INPUT (BTU/HR) | STEAM GROSS OUTPUT (BTU/HR) | WATER GROSS OUTPUT (BTU/HR) | NET RATINGS STEAM (SQ.FT.) | NET RATINGS STEAM (MBH) | NET RATINGS WATER (MBH) | BOILER H.P. | THERMAL EFFICIENCY WATER | THERMAL EFFICIENCY STEAM |
---|---|---|---|---|---|---|---|---|---|---|
LGB-4R | 350,000 | 175,000 | 283,000 | 294,000 | 885 | 212 | 256 | 8.5 | 84% | 81% |
LGB-4 | 400,000 | 200,000 | 324,000 | 336,000 | 1013 | 243 | 292 | 9.7 | 84% | 81% |
LGB-5 | 520,000 | 260,000 | 421,000 | 436,000 | 1316 | 316 | 379 | 12.6 | 84% | 81% |
LGB-6 | 650,000 | 325,000 | 526,000 | 546,000 | 1644 | 395 | 475 | 15.7 | 84% | 81% |
LGB-7 | 780,000 | 390,000 | 631,000 | 655,000 | 1972 | 473 | 570 | 18.8 | 84% | 81% |
LGB-8 | 910,000 | 455,000 | 737,000 | 764,000 | 2304 | 553 | 664 | 22 | 84% | 81% |
LGB-9 | 1,040,000 | 520,000 | 842,000 | 873,000 | 2632 | 632 | 759 | 25.2 | 84% | 81% |
LGB-10 | 1,170,000 | 585,000 | 947,000 | 982,000 | 2960 | 710 | 854 | 28.3 | 84% | 81% |
LGB-11 | 1,300,000 | 650,000 | 1,053,000 | 1,092,000 | 3303 | 793 | 950 | 31.5 | 84% | 81% |
LGB-12 | 1,430,000 | 715,000 | 1,158,000 | 1,201,000 | 3666 | 880 | 1044 | 34.6 | 84% | 81% |
LGB-14 | 1,690,000 | 845,000 | 1,368,000 | 1,419,000 | 4394 | 1054 | 1234 | 40.9 | 84% | 81% |
LGB-16 | 1,950,000 | 975,000 | 1,579,000 | 1,638,000 | 5108 | 1226 | 1424 | 47.2 | 84% | 81% |
LGB-18 | 2,210,000 | 1,105,000 | 1,790,000 | 1,856,000 | 5791 | 1390 | 1614 | 53.5 | 84% | 81% |
LGB-20 | 2,470,000 | 1,235,000 | 2,000,000 | 2,074,000 | 6470 | 1553 | 1803 | 59.7 | 84% | 81% |
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