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  • Lochinvar Knight WHN399 330000 BTU High Efficiency Wall Mount Boiler Natural Gas

    Brand & Part #: Lochinvar WHN399 SKU #: locwhn399

    UPC #:

    Lochinvar Knight WHN399 330000 BTU High Efficiency Wall Mount Boiler Natural Gas, WHN399

    Availability : In stock

    Only 1 left

    Regular Price: Was: $11,403.13


    You Save $4,003.14 (35%)

    Additional Documents

    Product Specifications

    Helpful Information



    Lochinvar Knight WHN399 330000 BTU High Efficiency Wall Mount Boiler Natural Gas

    The KNIGHT Wall Mount, engineered with Lochinvar’s exclusive SMART SYSTEM control and an array of other innovative features is far ahead of any heating boiler in its class. It promises and delivers ultimate ease of installation and maintenance. With up to 99% thermal efficiency, low-NOx emissions and a fully modulating burner, it is the best ”green choice” for today’s environmentally focused market.

    Seven modulating/condensing stainless steel KNIGHT Wall Mount boilers are available with 55,000–399,999 Btu/hr inputs in a space-saving wall-mounted design. All are equipped for direct-vent installation with air intake and exhaust runs up to 100 feet using PVC, CPVC, Polypropylene or AL29-4C vent materials. This range of choices is ideal for residential or light-duty applications such as small hotels, schools and office buildings. For higher-demand applications, up to eight KNIGHT Wall Mount units can be installed utilizing the built-in cascading sequencer to deliver up to 3.2 million Btu/hr heating capacity. The new KNIGHT Wall Mount Boiler reflects Lochinvar’s constant commitment to providing all the options you need to serve every application.


    Standard Features

    Energy Star Qualified
    96% DOE AFUE Efficiency
    Modulating Burner with 5:1 Turndown

    • Direct-Spark Ignition
    • Low-NOx Operation
    • Field Convertible from Natural to LP Gas

    ASME Stainless Steel Heat Exchanger

    • 30 psi ASME Relief Valve

    Vertical & Horizontal Direct-Vent

    • PVC, CPVC, Polypropylene or SS Venting up to 100 feet
    • Factory Supplied Sidewall Vent Termination

    Smart System Control
    Condensate Trap
    Other Features

    • Automatic Reset High Limit
    • Adjustable High Limit w/Manual Reset
    • Boiler Circulating Pump
    • Wall-Mount Bracket
    • Zero Clearances to Combustible Materials
    • 12-Year Limited Warranty




    Smart System Features

    SMART SYSTEM Digital Operating Control

    • Multi-Color Graphic LCD Display with Navigation Dial and Soft Keys

    Three Boiler Setpoint Temperature Inputs

    • Plus Domestic Hot Water Prioritization

    Built-in Cascading Sequencer for up to 8 Boilers

    • Multiple Size Boiler Cascade
    • Lead Lag
    • Efficiency Optimization
    • Outdoor Reset Control with Outdoor Air Sensor
    • Programmable for Three Reset Temperature Inputs

    Programmable System Efficiency Optimizers

    • Night Setback
    • DHW Night Setback
    • Anti-Cycling
    • Outdoor Air Reset Curve
    • Ramp Delay
    • Boost Temperature & Time

    Three Pump Control

    • System Pump with Parameter for Continuous Operation
    • Boiler Pump with Variable Speed Pump Control
    • Domestic Hot Water Pump

    Domestic Hot Water Prioritization

    • DHW tank piped with priority in the boiler loop
    • DHW tank piped as a zone in the system with the pumps controlled by the Smart System
    • DHW Modulation Limiting
    • Separately Adjustable Space Heat/DHW Switching Times

    Building Management System Integration

    • 0-10 VDC Input to Control Modulation or Set Point
    • 0-10 VDC Modulation Rate Output
    • 0-10 VDC Input to Enable/Disable call for heat

    Access to BMS Settings through Graphic LCD Display
    High-Voltage Terminal Strip

    • 120 VAC / 60 Hertz / 1 Phase Power Supply
    • Three Sets of Pump Contacts

    Low Voltage Terminal Strip

    • 24 VAC Device Relay
    • Proving Switch Contacts
    • Flow Switch Contacts
    • Alarm on Any Failure Contacts
    • Runtime Contacts
    • DHW Thermostat Contacts
    • 3 Space Heat Thermostat Contacts
    • System Sensor Contacts
    • DHW Tank Sensor Contacts
    • Outdoor Air Sensor Contacts
    • Cascade Contacts
    • 0-10 VDC BMS External Control Contact
    • 0-10 VDC Boiler Rate Output Contacts
    • 0-10 VDC Variable Speed System Pump Signal Input
    • 0-10 VDC Signal to Control Variable Speed Boiler Pump
    • Modbus Contacts

    Time Clock
    Data Logging

    • Hours Running, Space Heating
    • Hours Running, Domestic Hot Water
    • Ignition Attempts
    • Last 10 Lockouts

    Maintenance Reminder

    • Custom Maintenance Reminder with Contractor Contact Information
    • Installer Ability to De-activate Service Reminder

    Low-Water Flow Safety Control & Indication
    Password Security
    Customizable Freeze Protection Parameters


    Fuel Type: Natural Gas
    Efficiency: 96%
    System Type: Hydronic (Water)
    Features: Condensing

    Direct Vent

    EI/Spark Ignition

    Wall Mounted
    Depth (Inches): 21-3/4"
    Vent Size: 4"
    BTU Output: 330000
    BTU Input: 399000
    Boiler Type: High Efficiency
    Width (Inches): 25"
    Height (Inches): 35.50
    Application: Heating
    Water Connection: 1-1/2"
    Gas Connection: 3/4"

    Additional Info

    Additional Info

    MPN WHN399
    Brands Lochinvar
    BTU Input 200,000 and Above
    BTU Output 200,000 and Above
    Availability Available to Ship Immediately


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