NCB700 ON The Powerful Combi Crossover
The game-changing NCB700 ON combi gas boiler from Navien is the first product of its type capable of delivering hot water to three bathrooms simultaneously. Shattering all preconceptions of a combi boiler’s suitability for large properties, the NCB700 ON cleverly maximises recirculation of domestic hot water (DHW) to significantly reduce water wastage and offer flow rates up to an industry-leading 22 litres per minute (at 35°C temperature rise).
- Powerful 54kW hot water output delivering up to 22lpm
- Industry-leading turndown ratio of 15:1 for supreme efficiencies
- Easy to use built-in digital display panel displays energy usage
- 12-year warranty for complete peace of mind
- ErP A+ energy efficiency rating for ultra-low running costs*
- NaviCirc™ for simple and fast set up of hot water return system
- Built-in DHW recirculation pump for super fast hot water delivery
- Stainless steel heat exchangers for optimum durability and long term efficiencies
- Hydrogen-ready (20% blend) technology for futureproofing
- 3-zone ready with Smart Plus control pack
* An A+ energy rating is achieved when installed with a single Smart Plus room thermostat.
Technical Data
| NCB700-2S+/42K | NCB700-3S/54K | ||
| Shower rating | Number of showers | Two showers & one tap | Three showers |
| Heat Output | Heat input range | 35.0/3.5kW | 35/3.5kW |
| Modulation (max/min) | 10:1 | 15:1 | |
| Heat output range @ 80/60°C | 34.0/3.4kW | 34.0/3.4kW | |
| DHW | DHW heat input range | 40.6/3.5kW | 52.4/3.5kW |
| DHW output range | 42.0/3.5kW | 54.0/3.5kW | |
| DHW flow rate @ 25°C temp. rise. | 24.1l/min | 31l/min | |
| DHW flow rate @ 30°C temp. rise. | 20.1l/min | 25.8l/min | |
| DHW flow rate for kitchen @ 45°C temp. rise. | 13.4l/min | 17.2l/min | |
| Flue | Flue Size | Coaxial length Ø 60/100 | |
| Max. horizontal coaxial length Ø60/100 | 20m | ||
| Max. vertical coaxial length Ø60/100 | 21m | ||
| Weight | Lift weight | 43kg | 46kg |
| Dimensions | Width x Depth x Height | 440 x 335 x 695mm | |
| ErP Efficiency | ErP A (94%) | ||
| ErP Efficiency with Single Smart Plus | ErP A+ (98%) | ||
| NOx Classification | Class 6 | ||
Downloads
- NCB700 ON / 500 ON / 300 brochure (23.01 MB)
- NCB700 User Manual – Combi (4.65 MB)
- NCB700 IOM Manual – Combi (36.18 MB)
- NCB700 Service Manual – Combi (30.30 MB)
- A successful NCB700 installation in East Sussex (1.26 MB)
- The NCB700 gets hot water to the 3rd floor (1.04 MB)
- An energy efficient ‘crossover’ combi installation. (1.83 MB)
- The first Navien NCB700 installation in Scotland by MPH (1.38 MB)
NCB700 FAQ’s
What does the fault code E302 mean for the NCB700?
E302 means that the system pressure is too low and you may see that the system pressure gauge or on the front display indicates that the pressure in the system is below the 1 bar pressure. To re-pressurise the system, you will find a NaviFill Link (a plastic and brass link with a green plastic leaver) on the underside of the boiler.
The green leaver needs to be pulled down slowly. The water will start to refill the system (water should be heard filling the system). You should see the pressure gauge or the pressure reading on the display rise back up between 1 bar and 1.2 bar pressure and then stop filling. Once the pressure gauge or pressure reading on the display is between 1 bar and 1.2 bar release the green leaver and the water will stop filling the system. The error code E302 will stop and the boiler will now operate. If the error code E302 is still active, fill up the system a little more but not over 1.5 bar.
(If you do fill the system too much and the pressure gauge is too high, just bleed water from a radiator until the pressure on the gauge goes down to below 1.2 bar).
