GT-540-NIH - ProLine® XE Condensing Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater

Model GT-540-NIH 100
Installation Type
Fuel Source
Maximum BTU's

  • Highly efficient with a UEF of 0.93
  • Compact Design—Space-saving design suitable for indoor and outdoor installations
  • Safety features include Air-Fuel Ratio (AFR) sensors, exhaust and water temperature controls, overheat cut-off fuses, and internal freeze protection systems
  • GT-540-NIH - ProLine® XE Condensing Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater
    Model GT-540-NIH 100
    What to Expect from this Model
    modal-clock
    Unlimited
    single shower length
    modal-frame
    Unlimited
    back-to-back
    modal-frame
    2.7 showers
    at the same time
    modal-tank-capacity
    Unlimited
    max tub size
    modal-cost
    $208/year
    est. energy cost
    Based on location results for Columbus, OH 43215
    Product Details
    • Highly efficient with a UEF of 0.93
    • Compact Design—Space-saving design suitable for indoor and outdoor installations
    • Safety features include Air-Fuel Ratio (AFR) sensors, exhaust and water temperature controls, overheat cut-off fuses, and internal freeze protection systems
    • Easy-link capability connects up to 4 heaters, while multi-linking supports up to 20 units for scalability
    • Common venting supports up to 8 units, simplifying installation
    • Indoor models include integrated temperature controllers and advanced diagnostics for simplified troubleshooting
    • Durable heat exchangers ensure reliability, with commercial-grade copper for superior heat transfer and stainless steel for corrosion resistance
    • Power direct vent design supports PVC, CPVC, or ABS piping
    • Ultra-low NOx condensing technology provides up to a 0.95 Uniform Energy Factor
    • 15-year limited warranty on heat exchanger

    • Tankless Condensing High Efficiency water heaters deliver continuous hot water while maximizing energy savings through advanced condensing technology. The primary heat exchanger is constructed with commercial-grade copper, which enhances heat transfer and resists erosion, while the secondary heat exchanger uses Type 316L stainless steel to prevent corrosion. These water heaters provide maximum flow rates of up to 10.0 GPM and offer flexibility with natural gas or liquid propane options. Indoor models include temperature controllers and diagnostics for easy troubleshooting, while outdoor models include wall-mounted remote temperature controllers for added convenience.

      These versatile water heaters perform in both residential and commercial applications, scaling to meet varying demands. Users can link up to 4 heaters with Easy-Link or connect up to 20 units using a Multi-Unit controller for larger systems. Power direct vent design supports PVC, CPVC, or ABS piping. They are equipped with advanced safety features, including Air-Fuel Ratio (AFR) sensors, temperature controls, overheat cut-off fuses, and internal freeze protection systems. With 15-year warranties for residential applications, these heaters provide a reliable, efficient, and durable solution for modern water heating needs.

    Specifications
    Tech Specs
    UEF
    0.93
    Maximum BTUs
    199,000
    Power Source
    GAS
    Limited Parts Warranty
    5 Years
    Water Connection Location
    BOTTOM
    Emissions
    Ultra-Low NOx
    ASME Certified
    No
    Destination Country
    US
    Digital Display
    Yes
    Fuel Source
    NATURAL
    Installation Type
    INDOOR
    Limited Heat Exchanger Warranty 
    15 Years
    Max Flow Rate
    5.8 GPM
    Minimum BTUs
    15,000
    Application
    RESIDENTIAL
    Shipping Height 
    33.25
    Shipping Length 
    21.75
    Shipping Width 
    15.625
    Side Loop
    No
    Dimension & Venting
    Type
    Water Heater
    Height
    23.63"
    Width
    17.75"
    Shipping Weight
    70 lbs
    Vent Type
    Power Direct Vent
    Find a Replacement
    Current Product
    Option 2
    GT-540-NIH - ProLine® XE Condensing Ultra-Low NOx Indoor 199,000 BTU Natural Gas Tankless Water Heater
    Adapt® SC Standard Condensing Ultra-Low NOx 199,000 BTU Natural Gas Tankless Water Heater
    GT-540-NIH
    MTM-199M-N
    Up to $300 Rebates
    Up to $300 Rebates
    Nominal Capacity
    1 Gallons
    Width
    17.75"
    17.12"
    Depth
    11.25"
    11.85"
    Height
    23.63"
    32.46"
    Shipping Weight
    70lbs
    93lbs
    Power Source
    GAS
    GAS
    Limited Tank Warranty
    0 Years
    0 Years
    Limited Parts Warranty
    5 Years
    5 Years
    Water Connection Location
    BOTTOM
    BOTTOM
    Water Connection Size
    0.75"
    Thermal Efficiency
    0%
    0%