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.

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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
  • ENERGY STAR® certified (0.95 UEF)
  • 180,000 BTU input
  • 15-Year Warranty
|
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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
  • ENERGY STAR® certified (0.95 UEF)
  • 160,000 BTU input
  • 15-Year Warranty
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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
  • ENERGY STAR® certified (0.95 UEF)
  • 199,000 BTU input
  • 15-Year Warranty
|
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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
  • ENERGY STAR® certified (0.95 UEF)
  • 199,000 BTU input
  • 15-Year Warranty
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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
  • ENERGY STAR® certified (0.95 UEF)
  • 180,000 BTU input
  • 15-Year Warranty
|
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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
  • ENERGY STAR® certified (0.95 UEF)
  • 160,000 BTU input
  • 15-Year Warranty
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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
  • Endless Hot Water
  • 199,000 BTU input
  • 15-Year Warranty
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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
  • X3® Technology
  • Concentric Vent
  • 15-Year Warranty
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ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology
ProLine® XE Ultra-Low NOx Indoor Natural Gas Tankless Water Heater with X3® Technology Model ATI-540HX3-N
  • 199,000 BTU input
  • 15-Year Warranty
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ProLine® XE Ultra-Low NOx Outdoor Liquid Propane Tankless Water Heater with X3® Technology
Energy Star
ProLine® XE Ultra-Low NOx Outdoor Liquid Propane Tankless Water Heater with X3® Technology Model ATO-540HX3-P
  • ENERGY STAR® certified
  • 199,000 BTU input
  • 15-Year Warranty
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ProLine® XE Concentric Vent Indoor 190,000 BTU Non-Condensing Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
ProLine® XE Concentric Vent Indoor 190,000 BTU Non-Condensing Natural Gas Tankless Water Heater with X3® Scale Prevention Technology Model ATI-310CX3
  • X3® Scale Prevention Technology
  • Concentric Vent
  • 15-Year Warranty
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ProLine® XE Ultra-Low NOx Outdoor Natural Gas Tankless Water Heater with X3® Technology
Energy Star
ProLine® XE Ultra-Low NOx Outdoor Natural Gas Tankless Water Heater with X3® Technology Model ATO-540HX3-N
  • ENERGY STAR® certified
  • 199,000 BTU input
  • 15-Year Warranty
|
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ProLine® XE Ultra-Low NOx Indoor Liquid Propane Tankless Water Heater with X3® Technology
ProLine® XE Ultra-Low NOx Indoor Liquid Propane Tankless Water Heater with X3® Technology Model ATI-540HX3-P
  • Endless Hot Water
  • 199,000 BTU input
  • 15-Year Warranty
|
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ProLine® XE Ultra-Low NOx Outdoor Natural Gas Tankless Water Heater with X3® Technology
ProLine® XE Ultra-Low NOx Outdoor Natural Gas Tankless Water Heater with X3® Technology Model ATO-340HX3-N
  • Endless Hot Water
  • 180,000 BTU input
  • 15-Year Warranty
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ProLine® XE Ultra-Low NOx Outdoor 140,000 BTU Non-Condensing Natural Gas/Liquid Propane Tankless Water Heater
ProLine® XE Ultra-Low NOx Outdoor 140,000 BTU Non-Condensing Natural Gas/Liquid Propane Tankless Water Heater Model ATO-110U
  • Endless Hot Water
  • 140,000 BTU input
  • 15-Year Warranty
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Showing 1-15 of 40
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