Natural Gas Boilers

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294 Products

Learn More About Burnham KIN6LNI-LE2
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Disassembled. Ratings: 175K BTU Gross Input, 144K BTU DOE Capacity, 108K BTU Net IBR Capacity.
$4,383.54
Factory-Direct
Free Shipping & Lift Gate
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*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
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2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain EVG 299
Floor/Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 299K BTU Gross Input, 280K BTU DOE Capacity, 243K BTU Net IBR Capacity. Includes Circulator.
$8,875.91
In-Stock
Free Shipping & Lift Gate
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Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain EVG 399
Floor/Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 399K BTU Gross Input, 383K BTU DOE Capacity, 333K BTU Net IBR Capacity. Includes Circulator.
$10,546.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ALP399BF-4L07
Floor Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 399K BTU Gross Input, 377K BTU DOE Capacity, 328K BTU Net IBR Capacity.
$11,816.24
Factory-Direct
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain EVG 155
Floor/Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 155K BTU Gross Input, 143K BTU DOE Capacity, 124K BTU Net IBR Capacity. Includes Circulator.
$4,377.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain 381359078
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Packaged. Ratings: 166k BTU Gross Input, 141k BTU DOE Capacity, 123k BTU Net IBR Capacity. Includes Circulator.
$3,240.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Triangle Tube PA299
Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 299K BTU Gross Input, 278K BTU DOE Capacity, 242K BTU Net IBR Capacity. Includes Circulator.
$8,245.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Triangle Tube INS199S
Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 199K BTU Gross Input, 184K BTU DOE Capacity, 159K BTU Net IBR Capacity.
$2,920.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Triangle Tube INS199C
Wall Mounted, Condensing Combi Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 199K BTU Gross Input, 184K BTU DOE Capacity, 159K BTU Net IBR Capacity. Includes Circulator.
$2,854.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain 381359004
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Packaged. Ratings: 90k BTU Gross Input, 77k BTU DOE Capacity, 67k BTU Net IBR Capacity. Includes Circulator.
$3,100.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain 381359006
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Packaged. Ratings: 119k BTU Gross Input, 102k BTU DOE Capacity, 89k BTU Net IBR Capacity. Includes Circulator.
$3,435.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-320A-6L00
Wall/Floor Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 320K BTU Gross Input, 304K BTU DOE Capacity, 264K BTU Net IBR Capacity.
$9,227.66
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-399A-6L00
Wall/Floor Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 399K BTU Gross Input, 379K BTU DOE Capacity, 330K BTU Net IBR Capacity.
$11,755.24
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-110A-6L00M
Wall Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 110K BTU Gross Input, 103K BTU DOE Capacity, 90K BTU Net IBR Capacity.
$4,234.97
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-155A-6L00M
Wall Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 155K BTU Gross Input, 145K BTU DOE Capacity, 126K BTU Net IBR Capacity.
$4,961.01
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-270A-6L00M
Wall Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 270K BTU Gross Input, 252K BTU DOE Capacity, 219K BTU Net IBR Capacity.
$7,190.75
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-085A-6L00M
Wall Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 85K BTU Gross Input, 79K BTU DOE Capacity, 69K BTU Net IBR Capacity.
$4,030.37
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ASPN-205A-6L00M
Wall Mounted Condensing Boiler with Modulating Gas Valve. Ships Packaged. Low Nox. Ratings: 205K BTU Gross Input, 189K BTU DOE Capacity, 164K BTU Net IBR Capacity.
$6,042.84
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Triangle Tube INS110S
Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 110K BTU Gross Input, 102K BTU DOE Capacity, 89K BTU Net IBR Capacity.
$2,555.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain 383900176
Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 80K BTU Gross Input, 74K BTU DOE Capacity, 64K BTU Net IBR Capacity. Includes Circulator.
$3,326.53
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Weil-McLain 383600331
Floor Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 750K BTU Gross Input, 702K BTU DOE Capacity, 610K BTU Net IBR Capacity.
$17,725.79
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ES28BNI-T
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Packaged. Ratings: 245K BTU Gross Input, 208K BTU DOE Capacity, 181K BTU Net IBR Capacity. Includes Circulator.
$5,605.48
Factory-Direct
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Burnham ES29BNI-T
Floor Mounted, Cast Iron Boiler with Single Stage Gas Valve. Ships Packaged. Ratings: 280K BTU Gross Input, 208K BTU DOE Capacity, 207K BTU Net IBR Capacity. Includes Circulator.
$6,264.24
Factory-Direct
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.
Learn More About Triangle Tube PA110
Wall Mounted, Condensing Boiler with Modulating Gas Valve. Ships Packaged. Ratings: 110K BTU Gross Input, 102K BTU DOE Capacity, 89K BTU Net IBR Capacity. Includes Circulator.
$4,241.00
In-Stock
Free Shipping & Lift Gate
Learn More About Free Freight
Free Shipping & Lift Gate
*This product qualifies for Free Shipping anywhere in the contiguous US. Accessories may ship separately. Items over 100lbs shipped via semi-truck, be sure to select "Lift Gate" to lower the product to the ground curbside. Remote area surcharges may apply, see our full shipping policy for more details.
2% Check Discount
Learn More About 2% Check Discount
2% Check Discount
Save 2% instantly by using our convenient "e-check" option or by simply mailing us a paper check. Yes, your order will be delayed slightly (5 business days). But, if you can wait, the savings are significant.

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About Natural Gas Boilers

Shop a wide assortment of natural gas boilers from top brands like ProSelect, Weil-McClain, and Noritz.

Shop by Medium:

Choose between hot water and steam boilers. When replacing an old boiler, you need to identify whether it used hot water or steam to find the right replacement. Steam-fired boilers will have a small glass tube, called a sight glass, mounted on the side of the boiler. Hot water boilers will not have a sight glass but are likely to have other accessories installed nearby, such as a pump or expansion tank.

Shop by Vent Type:

We offer boilers with one of three different venting configurations.

  • Chimney-vented boilers eject spent combustion gases through a vertical stack or chimney.
  • Power-vented boilers use a built-in blower to push spent gases outside. They offer the flexibility to vent through a sidewall or the ceiling without needing to use a chimney.
  • Direct vent boilers pull air for combustion directly from outside the house. This means the entire combustion process is “sealed” from the indoors, and you are not exhausting the air you had already heated. They are particularly great for tight places, like closets or rooms without much air flow.

Shop by Efficiency:

Home boilers are typically available in efficiency ratings ranging from 80% - 96% Annual Fuel Utilization Efficiency (AFUE). A boiler's AFUE rating estimates the percentage of fuel that is converted into usable heat for the home. By comparing AFUE ratings, you can get an idea of how much a boiler may cost to operate. Condensing boilers are the most efficient because they use a secondary heat exchanger to collect heat from exhaust gases and repurpose it to preheat incoming water.

Staging/Modulation

Boilers can also save energy through staging or modulation.

  • Staging boilers have two or more distinct levels of heat output called stages. The boiler will operate at the lowest stage that meets your home’s heating needs.
  • Modulating boilers can produce any heat output between a defined minimum and maximum level for constant, even heat.

What are Combi Boilers?

A combination (combi) boiler combines a boiler and tankless domestic water heater into one, compact unit. There is no hot water tank. Instead, the boiler circulates hot water through a heat exchanger, which in turn heats incoming cold water on demand. The heated domestic water then flows to fixtures throughout the home.