A.O. Smith
ATHR-199X3 Adapt™ Premium Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
Sign In to View Pricing & Availability
- Delivering robust, on-demand performance, these high-efficiency heaters install in practically any residential setting. The single stainless steel, heavy-duty heat exchanger design is more resilient to scale buildup and corrosion and when coupled with X3 Scale Prevention Technology, there is zero lifetime descaling maintenance required.
Looking for model-specific repair or replacement parts? Enter the unit’s serial number into the A.O. Smith Parts Finder.
- Integrated Recirculation Pump
- Field convertible from Natural Gas to Liquid Propane, Kit Included
- 22:1 Turndown Ratio
- Max flow rate 10.5 GPM, 0.4 GPM activation
- 1/2" Gas Line
- Venting Flexibility 2" up to 75' & 3" up to 150'
- **Outdoor Vent Cap Kit Required, Kit Sold Separately
- X3® Scale Prevention Technology
- Flow Rate10.5 gpm MaxFuel TypeNatural GasHeating Capacity199,000 BTU/hrIndoor / OutdoorIndoor / OutdoorUltra Low NOxYesVent TypePower DirectDimensions44.6 in H x 16.1 in D x 16.5 in WManufacturerA.O. SmithManufacturer #100374812SeriesAdaptVoltage Rating120 VWeight104 lb