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.


  • NCB 150E :DHW 12-120 , HTG 12-60.
  • NCB 180E :DHW 14-150 , HTG 14-80.
  • NCB 210E : DHW 18-180, HTG 18-100.
  • NCB 240E : DHW 18-199, HTG 18-120.



  • 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.

Product Options:

Available options: NCB 150E:DHW 12-120,HTG 12-60NCB 180E:DHW 14-150,HTG 14-80NCB 210E:DHW 18-180,HTG 18-100NCB 240E:DHW 18-199,HTG 18-120