ProLine Residential Gas Tankless Water Heaters

Residential Gas Tankless Water Heaters

A. O. Smith offers a complete line of natural gas and liquid propane tankless water heaters for continuous hot water needs. Choose from ENERGY STAR® certified condensing models or non-condensing models.

A. O. Smith
Showing 1-15 of 97
Display:
Sort by:
Refine your results
  • (34)
  • (10)
  • (6)
  • (6)
  • (32)
  • (35)
  • (15)
  • (2)
  • (19)
  • (6)
  • (21)
  • (23)
  • (19)
  • (13)
  • (12)
  • (10)
  • (34)
  • (38)
  • (4)
  • (40)
  • (20)
  • (24)
  • (53)
  • (44)
Try our Water Heater Selector
Use our
Water Heater Selector
Find your Water Heater
Showing 1-15 of 97
Display:
Sort by:
filter
Adapt™+ Premium Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATHR-199X3 100
  • ENERGY STAR® certified (0.95 UEF)
  • 199,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™+ Premium Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATHR-180X3 100
  • ENERGY STAR® certified (0.95 UEF)
  • 180,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™+ Premium Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATHR-160X3 100
  • ENERGY STAR® certified (0.95 UEF)
  • 160,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™+ Premium Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater Model ATHR-199M 100
  • ENERGY STAR® certified (0.95 UEF)
  • 199,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™+ Premium Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater Model ATHR-180M 100
  • ENERGY STAR® certified (0.95 UEF)
  • 180,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™+ Premium Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™+ Premium Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater Model ATHR-160M 100
  • ENERGY STAR® certified (0.95 UEF)
  • 160,000 BTU input
  • 15-Year Warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATM-199X3-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 199,000 BTU input
  • 15-year limited warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATM-180X3-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 180,000 BTU input
  • 15-year limited warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATM-160X3-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 160,000 BTU input
  • 15-year limited warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater Model ATM-199M-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 199,000 BTU input
  • 15-year limited warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 180,000 BTU Natural Gas Tankless Water Heater Model ATM-180M-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 180,000 BTU input
  • 15-year limited warranty
|
View Model
Adapt™ SC Standard Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater
Energy Star
Adapt™ SC Standard Condensing Ultra-Low NOx 160,000 BTU Natural Gas Tankless Water Heater Model ATM-160M-N 100
  • ENERGY STAR® certified with a UEF of 0.95
  • 160,000 BTU input
  • 15-year limited warranty
|
View Model
ProLine® XE Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater
ProLine® XE Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater Model ATI-540P-N 100
  • Endless Hot Water
  • 199,000 BTU input
  • 15-Year Warranty
|
View Model
ProLine® XE Ultra-Low NOx Indoor 199,000 BTU Condensing Propane Tankless Water Heater
ProLine® XE Ultra-Low NOx Indoor 199,000 BTU Condensing Propane Tankless Water Heater Model ATI-540P-P 101
  • Endless Hot Water
  • 199,000 BTU input
  • 15-Year Warranty
|
View Model
ProLine® XE Concentric Vent Indoor 199,000 BTU Non-Condensing Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
ProLine® XE Concentric Vent Indoor 199,000 BTU Non-Condensing Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATI-510CX3 110
  • X3® Technology
  • Concentric Vent
  • 15-Year Warranty
|
View Model
Showing 1-15 of 97
Try our Water Heater Selector
Use our
Water Heater Selector
Find your Water Heater
Get it installed by a Local Pro
Get it installed by a

Local Pro

A. O. Smith water heaters are available through your local plumbing professional.
Find a Local Pro
0 of 2
selected
0 of 4
selected
Please select at least two products to compare.
Select 2-4 Products Compare Now
Clear Filters