NCB500 ON Combi Boiler for Installers
Our compact NCB500 ON combi boiler offers fast and flexible installation options – making it a great option for family homes that require a quick heating solution. Every Navien Combi Boiler features high-quality components to provide exceptional levels of reliability and performance.
What is ON technology?
Navien ON technology maximises the recirculation of domestic hot water whilst reducing water wastage – this means that boilers with ON technology can deliver instant and consistent hot water.
- ErP A+ energy efficiency rating*
- State-of-the-art flow adjustment valve and auto mixing valve
- Smartphone compatible offering remote adjustments of heating and hot water systems
- Smart weather forecasting and Geofencing
- Durable stainless steel heat exchangers
- 20% Hydrogen-ready
- Compact dimensions for easy installation in a kitchen cupboard
- 3-zone ready w/ Smart Plus control pack
- IPX4 rating provides protection from any water leaks
- Built-in digital display panel
- 10-year parts and labour warranty
* An A+ energy rating is achieved when installed with 3 Smart Plus room thermostats.
Technical Data
| NCB500-1S+/32k | NCB500-2S/37K | NCB500-2S/41K | ||
| Shower rating | Number of showers | One shower & one tap | Two Showers | Two Showers & one tap |
| Heat Output | Heat input range | 26.8/4.6kW | 26.8/4.6kW | 26.8/4.6kW |
| Modulation (max/min) | 6:1 | 6:1 | 6:1 | |
| Heat output range @ 80/60°C | 26.0/4.5kW | 26.0/4.5kW | 26.0/4.5kW | |
| DHW | DHW heat input range | 32.0/4.6kW | 37.0/4.6kW | 41.0/4.6kW |
| DHW output range | 32.0/4.6kW | 37.0/4.6kW | 41.0/4.6kW | |
| DHW flow rate @ 25°C temp. rise. | 18.4 l/min | 21.3 l/min | 23.6l/min | |
| DHW flow rate @ 35°C temp. rise. | 13.1l/min | 15.2l/min | 16.8l/min | |
| DHW flow rate for kitchen @ 45°C temp. rise. | 10.2l/min | 11.8l/min | 13.1l/min | |
| Modulation | TDR | 7:1 | 8:1 | 9:1 |
| Flue | Flue Size | Coaxial length Ø 60/100 | ||
| Max. horizontal coaxial length Ø60/100 | 8m | |||
| Max. vertical coaxial length Ø60/100 | 8m | |||
| Weight | Lift weight | 34kg | 34kg | 34kg |
| Dimensions | Width x Depth x Height | 395 x 285 x 680mm | ||
| ErP Efficiency | ErP A (93%) | |||
| ErP Efficiency with Smart Plus (x3) | ErP A+ (98%) | |||
| NOx Classification | Class 6 | |||
Navien NCB500 FAQ’s
What does the fault code E302 mean for the NCB500?
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).
