Condensing Combi-Boiler

The first high efficiency tankless condensing combi-boiler that can do it all

Navien NCB-E is the first high efficiency condensing combination boiler with the capacity to supply both heat and domestic hot water for larger homes — enough hydronic heat for a whole house, plus hot water to run two showers and a dishwasher all at the same time.

The Navien NCB-E saves installation time and reduces call backs. In addition, the NCB-E takes up 80% less space than a traditional floor standing boiler and tank water heater. Your customer now has more room, saves energy and enjoys all the hot water they need, whenever they want it.

Compare these advantages to any condensing combi system


  • Dual inputs of up to 120k BTU/H for heating and 199k BTU/H for DHW

    Supplies all the heat and domestic hot water that most houses require.

  • PVC Venting

    Low exhaust gas temperatures allows use of PVC, CPVC, ULC S636 and polypropylene vent systems, reducing installation time and costs. System can use 2" venting for up to 60', or up to 150' with 3" venting.

  • 4.5 GPM@77° temperature rise for domestic hot water

    Separate stainless steel flat plate heat exchanger for DHW creates the highest flow rate for any combi boiler in the industry.

  • Low gas pressure operation

    Our negative pressure gas valve ensures maximum performance all the way down to a minimum gas pressure of 3.5" of water column.

  • Turn down ratio of 6:1 for heating and 11:1 for DHW

    The sophisticated gas flow control system provides a high turn down ratio, reducing energy waste and excessive boiler cycling and enhances temperature control for DHW.

  • Uses existing ½" gas piping

    Save time and effort in retrofit applications with ½" gas lines for up to 24'.

  • Dual stainless steel heat exchangers

    Resist corrosion better than copper to provide longer life.

  • Space saving design

    Occupies 80% less space than a traditional floor standing boiler and storage tank.

  • Field gas convertibility

    Dual venturi system allows for easy field convertibility from NG to LP operation. Orifice for LP conversion included.

  • Linkability

    For extraordinarily largedomestic hot water flow demand, the NCB-E can be cascaded with our NPE units.

NCB-E Applications

  • Air handler
  • Hydronic heating
  • Hydronic fan coil
  • Baseboard radiator
  • Radiant floor

Manifold Kits

For fast installation and maximum efficiency, install our system matched manifold kits.

  • NCB Series Primary Manifold Kit

  • Secondary Manifold Kit

NCB-E Models

Max HTG Input: 60,000 BTU/H
Max DHW Input: 120,000 BTU/H
Indoor wall-hung
Max HTG Input: 80,000 BTU/H
Max DHW Input: 150,000 BTU/H
Indoor wall-hung
Max HTG Input: 100,000 BTU/H
Max DHW Input: 180,000 BTU/H
Indoor wall-hung
Max HTG Input: 120,000 BTU/H
Max DHW Input: 199,900 BTU/H
Indoor wall-hung

Optional Wi-Fi remote control system


NaviLink makes it easy to communicate with your Navien systems anywhere internet service is accessible. The NaviLink module attaches easily to any new or existing* Navien tankless water heater, combi‐boiler and boiler.

* Existing installations may require the purchase of a new main PCB and front control panel. Units produced on or after 2-22-16 will be compatible out of the box.

Available for Download
on IOS or Android