Your Browser is Not Currently Supported

We recommend using one of the following browsers for an optimal experience. Click a link below to download the latest browser version.

If you are already using one of these browsers, please make sure you're updated to the latest version.

Indoor Natural Gas Tankless Water Heaters

49 Products
Filters
Brand
View Less
Application
View More
Uniform Energy Factor Learn More
Uniform Energy Factor
Uniform Energy Factor (UEF) is a measurement of water heater energy efficiency. The higher the energy factor, the more efficient the water heater.
View More
+ Show More
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.
View More
Flow Rate at 40F Temperature Rise (GPM) Learn More
Flow Rate at 40F Temperature Rise (GPM)
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location.
View More
Flow Rate at 50F Temperature Rise (GPM) Learn More
Flow Rate at 50F Temperature Rise (GPM)
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location.
View More
Flow Rate at 60F Temperature Rise (GPM) Learn More
Flow Rate at 60F Temperature Rise (GPM)
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location.
View More
Flow Rate at 70F Temperature Rise (GPM) Learn More
Flow Rate at 70F Temperature Rise (GPM)
Flow rate measures how much hot water your heater can deliver. Click Learn More to determine the appropriate temperature rise to use based on your location.
View More
Product Width (Inches)
View More
Product Height (Inches)
View More
+ Show More
Includes Pump
View More
Price
View More
To
+ Show More
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.
View More
+ Show More
Product Line
View More
+ Show More
Product Sub-line
View More
EnergyStar Condensing Water Heater. Ultra-Low NOx Emissions. Ratings: 9.6 GPM at 40° F Rise, 7.6 GPM at 50° F Rise, 6.3 GPM at 60° F Rise, 5.3 GPM at 70° F Rise. 199k BTU/h.
Item#: 154116
Model#: ATHR-199X3
Brand: A.O. Smith
Sale: $1,878.40
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Free Lift Gate
Learn More
Free Lift Gate
*This product qualifies for Free Lift Gate Service. Items over 100lbs normally ship via semi-truck. Select this service if you need the product lowered to the ground curbside. To learn more about Lift Gate Service, read our shipping policy.
In-Stock
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 9.5 GPM at 40° F Rise, 7.5 GPM at 50° F Rise, 6.3 GPM at 60° F Rise, 5.4 GPM at 70° F Rise. 199k Max BTU/h.
Item#: 61571
Model#: ATI-540H-N
Brand: A.O. Smith
$1,377.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
Wall Mounted, Condensing Water Heater Ultra Low NOx Emissions Concentric Vent. Ratings: 6.0 GPM at 40° F Rise, 4.8 GPM at 50° F Rise, 4.0 GPM at 60° F Rise, 3.5 GPM at 70° F Rise. 130k Effective BTU/h.
Item#: 77048
Model#: RUCS65IN
Brand: Rinnai
$649.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Only 1 In-Stock
EnergyStar Condensing Water Heater. Ultra-Low NOx Emissions. Ratings: 8.5 GPM at 40° F Rise, 6.8 GPM at 50° F Rise, 5.8 GPM at 60° F Rise, 4.9 GPM at 70° F Rise. 180k BTU/h.
Item#: 154115
Model#: ATHR-180X3
Brand: A.O. Smith
Sale: $1,712.40
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Free Lift Gate
Learn More
Free Lift Gate
*This product qualifies for Free Lift Gate Service. Items over 100lbs normally ship via semi-truck. Select this service if you need the product lowered to the ground curbside. To learn more about Lift Gate Service, read our shipping policy.
In-Stock
EnergyStar Condensing Water Heater. Low NOx Emissions. Ratings: 8.0 GPM at 40° F Rise, 6.8 GPM at 50° F Rise, 5.7 GPM at 60° F Rise, 4.8 GPM at 70° F Rise. 171k Effective BTU/h.
Item#: 61570
Model#: ATI-340H-N
Brand: A.O. Smith
$1,239.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 9.5 GPM at 40° F Rise, 7.5 GPM at 50° F Rise, 6.2 GPM at 60° F Rise, 5.2 GPM at 70° F Rise. 199k Max BTU/h.
Item#: 123210
Model#: ATI-540HX3-N
Brand: A.O. Smith
Sale: $1,642.40
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 8 GPM at 40° F Rise, 6.8 GPM at 50° F Rise, 5.8 GPM at 60° F Rise, 4.9 GPM at 70° F Rise. 180k Max BTU/h.
Item#: 123233
Brand: State Water Heaters
$1,421.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
Wall Mounted, Non-Condensing Boiler Water Heater Ultra Low NOx Emissions Ratings: 8.2 GPM at 40° F Rise, 6.6 GPM at 50° F Rise, 5.5 GPM at 60° F Rise, 4.6 GPM at 70° F Rise. 199k Effective BTU/h
Item#: 132520
Model#: RE199IN
Brand: Rinnai
$1,202.67
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
$804.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
$1,243.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
$1,370.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
In-Stock
Wall Mounted, Condensing Boiler Water Heater Ultra Low NOx Emissions Ratings: 6.2 GPM at 40° F Rise, 5.0 GPM at 50° F Rise, 4.2 GPM at 60° F Rise, 3.6 GPM at 70° F Rise. 130 k Effective BTU/h.
Item#: 154040
Model#: RX130IN
Brand: Rinnai
$1,141.70
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Free Lift Gate
Learn More
Free Lift Gate
*This product qualifies for Free Lift Gate Service. Items over 100lbs normally ship via semi-truck. Select this service if you need the product lowered to the ground curbside. To learn more about Lift Gate Service, read our shipping policy.
In-Stock
Wall Mounted, Condensing Boiler Water Heater Ultra Low NOx Emissions Ratings: 9.8 GPM at 40° F Rise, 7.8 GPM at 50° F Rise, 6.4 GPM at 60° F Rise, 5.6 GPM at 70° F Rise. 199 k Effective BTU/h.
Item#: 154043
Model#: RX199IN
Brand: Rinnai
$1,537.90
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Free Lift Gate
Learn More
Free Lift Gate
*This product qualifies for Free Lift Gate Service. Items over 100lbs normally ship via semi-truck. Select this service if you need the product lowered to the ground curbside. To learn more about Lift Gate Service, read our shipping policy.
In-Stock
Wall Mounted, Condensing Boiler Water Heater Ultra Low NOx Emissions Ratings: 9.8 GPM at 40° F Rise, 7.8 GPM at 50° F Rise, 6.4 GPM at 60° F Rise, 5.4 GPM at 70° F Rise. 199 k Effective BTU/h.
Item#: 154047
Model#: CX199IN
Brand: Rinnai
$1,582.70
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Free Lift Gate
Learn More
Free Lift Gate
*This product qualifies for Free Lift Gate Service. Items over 100lbs normally ship via semi-truck. Select this service if you need the product lowered to the ground curbside. To learn more about Lift Gate Service, read our shipping policy.
In-Stock
EnergyStar Water Heater. Ultra Low NOx Emissions. Ratings: 8.3 GPM at 40° F Rise, 6.9 GPM at 50° F Rise, 5.5 GPM at 60° F Rise, 4.8 GPM at 70° F Rise. 199k Max BTU/h.
Item#: 69986
Model#: ATI-510U-N
Brand: A.O. Smith
Sale: $1,006.05
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Low NOx Emissions. Ratings: 6.7 GPM at 40° F Rise, 6.1 GPM at 50° F Rise, 5.0 GPM at 60° F Rise, 4.3 GPM at 70° F Rise. 152k Effective BTU/h.
Item#: 61572
Model#: ATI-240H-N
Brand: A.O. Smith
$1,109.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Low NOx Emissions. Ratings: 5.4 GPM at 40° F Rise, 4.4 GPM at 50° F Rise, 3.8 GPM at 60° F Rise, 3.2 GPM at 70° F Rise. 112k Effective BTU/h.
Item#: 61575
Model#: ATI-140H-N
Brand: A.O. Smith
$917.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Water Heater. Ultra Low NOx Emissions. Ratings: 5.8 GPM at 40° F Rise, 4.5 GPM at 50° F Rise, 3.9 GPM at 60° F Rise, 3.3 GPM at 70° F Rise. 140k Effective BTU/h.
Item#: 69978
Model#: ATI-110U-N
Brand: A.O. Smith
$845.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
$1,064.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
$1,259.00
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 9.5 GPM at 40° F Rise, 7.5 GPM at 50° F Rise, 6.3 GPM at 60° F Rise, 5.4 GPM at 70° F Rise. 199k Max BTU/h.
Item#: 76482
Model#: ATI-540P-N
Brand: A.O. Smith
Sale: $1,604.00
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
$1,635.70
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 6.7 GPM at 40° F Rise, 6.1 GPM at 50° F Rise, 5.1 GPM at 60° F Rise, 4.3 GPM at 70° F Rise. 160k Max BTU/h.
Item#: 123206
Model#: ATI-240HX3-N
Brand: A.O. Smith
Sale: $1,269.50
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct
EnergyStar Condensing Water Heater. Ultra-Low NOx. Ratings: 8 GPM at 40° F Rise, 6.8 GPM at 50° F Rise, 5.8 GPM at 60° F Rise, 4.9 GPM at 70° F Rise. 180k Max BTU/h.
Item#: 123208
Model#: ATI-340HX3-N
Brand: A.O. Smith
Sale: $1,393.90
On Sale Through 06/01
Free Shipping
Learn More
Free Shipping
*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 map apply, see our full shipping policy for more details.
Factory-Direct