Natural Gas Boilers

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DOE Heating Capacity (BTU) Learn More
DOE Heating Capacity (BTU)
Also referred to as Gross Output, this is the output of a boiler after accounting for combustion efficiency. We recommend sizing hot water boilers based on the DOE Heating Capacity.
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Net I=B=R Capacity (BTU) Learn More
Net I=B=R Capacity (BTU)
I=B=R, also referred to as Net Output or AHRI Capacity, is the rated heat output of a boiler after accounting for combustion efficiency, piping loss, and an extra pickup factor. We recommend sizing steam boilers based on the I=B=R rating.
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Maximum Input Capacity (BTU) Learn More
Maximum Input Capacity (BTU)
The Maximum Input Capacity describes how quickly the appliance will use fuel when delivering it's maximum capacity. The units may change depending on the fuel being used.
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AFUE (%) Learn More
AFUE (%)
AFUE (Annual Fuel Utilization Efficiency) measures the efficiency of combustion equipment over the entire heating season, and is calculated by dividing the amount of energy that is actually heating your home by the total energy contained in the fuel used by the boiler/furnace.
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Vent Type Learn More
Vent Type
Products that use combustion (burning) of fuel to create heat also create potentially dangerous gasses that need to be exhausted (AKA "Vented"). Depending on the product, venting can be done via a chimney, through a side wall, or use a second vent to provide fresh air to the appliance.
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Medium Learn More
Medium
Medium refers to the substance that carries heat through the heating system. Systems are either designed to use either Hot Water or Steam as a medium, and components are usually specific to one or the other.
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Modulating/Staging Learn More
Modulating/Staging
Stages are unique speeds or levels that equipment can operate at. More stages allow for better fine-tuned control of output, which improves comfort and efficiency. Modulating equipment can operate across a range of levels, giving the highest level of fine-tuned control.
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Ultra Low NOx Emissions Learn More
Ultra Low NOx Emissions
NOx is a byproduct of the combustion process, and it's output is regulated in some jurisdictions. Many regulators mirror SCAQMD rules, which regulate air quality for some parts of Southern California. Ultra Low NOx appliances emit less than 10-14 ng/J (nanogram per Joule) of NOx.
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Efficiency (%)
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Low NOx Emissions Learn More
Low NOx Emissions
NOx is a byproduct of the combustion process, and it's output is regulated in some jurisdictions. Many regulators mirror SCAQMD rules, which regulate air quality for some parts of Southern California. Low NOx appliances emit less than 40 ng/J (nanogram per Joule) of NOx.
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Product Line
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DHW Production Learn More
DHW Production
DHW (Domestic Hot Water) is potable water for uses other than space heat. Some boilers are able to provide DHW "out of the box", while others can do so with the purchase of optional accessories.
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Product Height (Inches)
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 175K BTU Gross Input, 144K BTU DOE Capacity, 108K BTU Net IBR Capacity.
Item#: 150674
Model#: SIN6LNI-LE2
Brand: Burnham
$4,383.54
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 210K BTU Gross Input, 173K BTU DOE Capacity, 130K BTU Net IBR Capacity.
Item#: 150675
Model#: SIN7LNI-LE2
Brand: Burnham
$4,905.21
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 245K BTU Gross Input, 202K BTU DOE Capacity, 152K BTU Net IBR Capacity.
Item#: 150676
Model#: SIN8LNI-LE2
Brand: Burnham
$4,932.00
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 100K BTU Gross Input, 82K BTU DOE Capacity, 62K BTU Net IBR Capacity.
Item#: 150677
Brand: Burnham
$4,341.79
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 125K BTU Gross Input, 103K BTU DOE Capacity, 77K BTU Net IBR Capacity.
Item#: 150678
Brand: Burnham
$4,935.66
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 150K BTU Gross Input, 124K BTU DOE Capacity, 93K BTU Net IBR Capacity.
Item#: 150679
Brand: Burnham
$5,146.60
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 200K BTU Gross Input, 165K BTU DOE Capacity, 124K BTU Net IBR Capacity.
Item#: 150681
Brand: Burnham
$5,907.95
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Floor Mounted, Cast Iron Boiler with Step-opening Gas Valve. Ships Packaged. Ratings: 250K BTU Gross Input, 206K BTU DOE Capacity, 155K BTU Net IBR Capacity.
Item#: 150682
Brand: Burnham
$6,720.90
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Floor Mounted, Cast Iron Boiler with Conversion Included. Ships Packaged. Ratings: 105K BTU Gross Input, 90K BTU DOE Capacity, 78K BTU Net IBR Capacity. Includes Circulator.
Item#: 150686
Model#: X-PV4N-T02
Brand: Burnham
$3,244.00
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Floor Mounted, Cast Iron Boiler with Conversion Included. Ships Packaged. Ratings: 140K BTU Gross Input, 120K BTU DOE Capacity, 104K BTU Net IBR Capacity. Includes Circulator.
Item#: 150687
Model#: X-PV5N-T02
Brand: Burnham
$4,083.04
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INSFS155S - Floor Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 155K BTU Gross Input, 142K BTU DOE Capacity, 123K BTU Net IBR Capacity.
Item#: 153928
Model#: INSFS155S
Brand: Triangle Tube
$4,269.00
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INSFS110S - Floor Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 110K BTU Gross Input, 102K BTU DOE Capacity, 89K BTU Net IBR Capacity.
Item#: 153929
Model#: INSFS110S
Brand: Triangle Tube
$4,057.00
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INSFS199S - Floor Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 199K BTU Gross Input, 184K BTU DOE Capacity, 159K BTU Net IBR Capacity.
Item#: 153930
Model#: INSFS199S
Brand: Triangle Tube
$4,652.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 350K BTU Gross Input, 283K BTU DOE Capacity, 212K BTU Net IBR Capacity.
Item#: 163379
Model#: 133044315
Brand: Weil-McLain
$9,225.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 350K BTU Gross Input, 294K BTU DOE Capacity, 256K BTU Net IBR Capacity.
Item#: 163380
Model#: 133041315
Brand: Weil-McLain
$8,541.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 400K BTU Gross Input, 324K BTU DOE Capacity, 243K BTU Net IBR Capacity.
Item#: 163381
Model#: 133044310
Brand: Weil-McLain
$9,225.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 400K BTU Gross Input, 336K BTU DOE Capacity, 292K BTU Net IBR Capacity.
Item#: 163382
Model#: 133041310
Brand: Weil-McLain
$8,541.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 520K BTU Gross Input, 421K BTU DOE Capacity, 316K BTU Net IBR Capacity.
Item#: 163383
Model#: 133054310
Brand: Weil-McLain
$10,621.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 520K BTU Gross Input, 436K BTU DOE Capacity, 379K BTU Net IBR Capacity.
Item#: 163384
Model#: 133051310
Brand: Weil-McLain
$9,936.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 650K BTU Gross Input, 526K BTU DOE Capacity, 395K BTU Net IBR Capacity.
Item#: 163385
Model#: 133064310
Brand: Weil-McLain
$12,673.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 650K BTU Gross Input, 546K BTU DOE Capacity, 475K BTU Net IBR Capacity.
Item#: 163386
Model#: 133061310
Brand: Weil-McLain
$12,010.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 780K BTU Gross Input, 631K BTU DOE Capacity, 473K BTU Net IBR Capacity.
Item#: 163387
Model#: 133074310
Brand: Weil-McLain
$14,249.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 780K BTU Gross Input, 655K BTU DOE Capacity, 570K BTU Net IBR Capacity.
Item#: 163388
Model#: 133071310
Brand: Weil-McLain
$13,586.00
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Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 910K BTU Gross Input, 737K BTU DOE Capacity, 553K BTU Net IBR Capacity.
Item#: 163389
Model#: 133084310
Brand: Weil-McLain
$16,082.00
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