• ENERGY STAR® certified with a UEF of 0.95
• Flexibility in Installation—PVC venting flexibility (2” up to 50’ & 3" up to 150’); Install indoor or outdoor (outdoor kit sold separately)
• Save up to $116/year on operating costs—Compared to a standard 50-gallon atmospheric vent natural gas tank water heater
• Lasts 3x Longer—Integrated X3® Scale Prevention Technology provides protection for the heat exchanger
• Expandable for Larger Applications—Cascade up to 12 like heaters when multiple water heaters are required to work in conjunction (cable included)
• Built-in Control Display—Check status, error codes and settings using the built-in display

The ATM-199X3-N ADAPT™ SC Standard condensing tankless water heater uses up to 199,000 BTUs of Natural Gas to deliver a max flow rate of 10.5 GPM. A. O. Smith’s ADAPT™ SC tankless water heaters deliver robust, on-demand performance and the flexibility to install in virtually any residential setting.

Built-in X3® Scale Prevention Technology helps maintain like-new performance by protecting the heat exchanger from build-up. Scale prevention protection can prolong the life of the heat exchanger by up to 300% as compared to an unprotected unit.

The ADAPT™ SC line features a built-in Control Display for setting and checking heater status and error codes.

All models are ENERGY STAR® certified with a Uniform Energy Factor of 0.95 and comply with Ultra-Low NOx regulations. All ADAPT™ SC models can be installed indoors or outdoors (outdoor vent cap kit sold separately).

Cascade up to 12 like heaters for larger applications requiring multiple water heaters to work in conjunction, cable included.

• Nominal Gallon Capacity 1 Gallons
• UEF 0.95
• Maximum BTUs 199,000
• Power Source GAS
• Limited Parts Warranty 5 Years
• Water Connection Location BOTTOM
• Water Connection Size 0.75"
• ASME Certified No
• Amperes 5
• Destination Country US
• ENERGY STAR® Certified Yes
• Flue Diameter 2.00
• Fuel Source NATURAL
• Installation Type BOTH
• Limited Heat Exchanger Warranty 15 Years
• Max Flow Rate 6 GPM
• Minimum BTUs 10,000
• Application RESIDENTIAL
• Product Tier ProLine® XE
• Shipping Height 17.38"
• Shipping Length 39.25"
• Shipping Width 22.13"
• Side Loop No
• Voltage 120

Dimension & Venting

• Type Water Heater
• Height 40.41"
• Width 17.12"
• Shipping Weight 93 lbs
• Vent Material ABS, PVC, CPVC and polypropylene