Navien NCB300-28K, Service Manual

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16 Technical Data
3.1 General Specifications
The table below lists the boiler’s general specifications.
Specifications Unit
NCB300-28K NCB300-37K NCB300-41K
Heat input range kW 24.7/4.3 26.8/4.6 26.8/4.6
DHW heat input range kW 28.0/4.3 37.0/4.6 41.0/4.6
Heat output range @ 80/60°C kW 24.0/4.2 26.0/4.5 26.0/4.5
DHW output range kW 28.0/4.3 37.0/4.6 41.0/4.6
Condensing heat output range @ 50/30°C kW 25.6/4.5 28.2/4.8 28.2/4.8
Full load efficiency at Max. output @ 80/60°C % 88.4 88.4 88.4
Full load efficiency at Max. output @ 50/30°C
(Condensing)
% 106.5 106.5 106.5
Partial load (30%) efficiency with 30°C return temp. % 108.5 108.5 108.5
Heat loss through the case with burner switched on % 0.1
Seasonal efficiency rate (SEDBUK 2009) - 88.9 89.0 89.0
NOx Classification - Class 6
Category - II2HY203P
Type - Heating and instantaneous hot water production
Heat output adjustment - Adjustable over entire Max./Min. output range
Type of heating installation - Close circuit
Max. heating operation pressure bar 2.5
Max. heating temperature °C 90
Adjustable heating temperature range °C 40-90
Expansion vessel volume L 6
Expansion vessel pre-charged pressure bar 1.0
Min. DHW working pressure bar 0.7 0.7 1.1
Min. DHW working flow l/min 2
Max. DHW working pressure bar 10
Adjustable DHW temperature range °C 30-65
DHW flow rate @ 25°C temp. rise. l/min 16.1 21.3 23.6
DHW flow rate @ 35°C temp. rise. l/min 11.5 15.2 16.8
DHW flow rate for kitchen @ 45°C temp. rise. l/min 9.0 11.8 13.1
Electrical power supply - 230V/50Hz
Nominal current A 0.6 0.6 0.6
Max. power consumption W 130 130 130
Appliance protection rating - IPX4D
Boiler mounting system type - Wall-mounted
Flue exhaust/Air intake system types - B23-C13-C33-C53-C83
3. Technical Data