Adapt® NC Non-Condensing Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology

Model STI-199X3-N 100
3.9 out of 5 Customer Rating
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X3® Scale Prevention Technology
Installation Type
Fuel Source
Maximum BTU's

  • Max Flow Rate up to 10.5 GPM
  • 199,000 BTU input
  • Ease Of Installation – 3/4” Gas Line or larger
  • Adapt® NC Non-Condensing Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater with X3® Scale Prevention Technology
    Model STI-199X3-N 100
    3.9 out of 5 Customer Rating
    • reviews, product
    • BV SEO Enabled: RR Not Found
    Product Details
    • Max Flow Rate up to 10.5 GPM
    • 199,000 BTU input
    • Ease Of Installation – 3/4” Gas Line or larger
    • Highly Efficient – 0.82 UEF
    • Cascade up to 12 units with one cable per heater (cable included)
    • Ultra Low NOx Emissions
    • Certified from Sea Level to 7,800 ft
    • Approved for installation in manufactured homes
    • 5-year limited warranty on all parts in residential applications
    • 15-year limited warranty on heat exchanger in residential applications

    • State Adapt® NC Non-Condensing Tankless water heaters with X3® scale prevention technology deliver exceptional performance for indoor or outdoor installations. X3® models feature patented technology which eliminates the need for annual descaling and extends the unit's life up to three times longer than unprotected heaters. Base models offer the same robust performance and ease of installation – using 3/4” (or larger) gas line, but require annual maintenance to prevent scale buildup.

      With a maximum flow rate of up to 10.5 gallons per minute and ultra-low NOx emissions, all models provide reliable, energy-efficient hot water on demand. These high-performing tankless water heaters feature a uniform energy factor of 0.82, comply with strict NOx emission standards, and provide freeze protection down to -5°F. Enjoy peace of mind with a 10-year heat exchanger warranty for base models (excludes coverage for hard water conditions) and a 15-year heat exchanger warranty for X3® models (no hard water exclusions). Indoor models use convenient concentric venting, while outdoor models come equipped with outdoor-rated power cords, and all X3® models include a pressure relief valve for added safety.

    Specifications
    Tech Specs
    Nominal Gallon Capacity
    1 Gallons
    UEF
    0.82
    Maximum BTUs
    199,000
    Power Source
    GAS
    Limited Parts Warranty
    5 Years
    Water Connection Location
    BOTTOM
    Water Connection Size
    0.75"
    First Hour Rating
    1 Gallons
    ASME Certified
    No
    Amperes
    5
    Destination Country
    US
    Flue Diameter
    3.00
    Fuel Source
    NATURAL
    Ignition Type
    Intermittent/Electronic
    Installation Type
    INDOOR
    Limited Heat Exchanger Warranty 
    15 Years
    GPM (@67 F Temp Rise)
    5.2 GPM
    Minimum BTUs
    10,000
    Application
    RESIDENTIAL
    Shipping Height 
    16.25
    Shipping Length 
    34.25
    Shipping Width 
    20.63
    Side Loop
    No
    Voltage
    120
    Dimension & Venting
    Type
    Water Heater
    Height
    37.5"
    Width
    15.5"
    Shipping Weight
    73 lbs
    Vent Material
    Category III
    Marketing Videos
    Adapt® NC Non-Condensing Gas Tankless Water Heater Features & Benefits
    All Reviews for Adapt® NC Tankless Non-Condensing X3 (100 series)
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