Navien NCB-24LSWE, Service Manual

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12 NCB Service Manual Version 1.0
2. Product Information
2.1 Product Information
The NCB series gas boiler is a fully modulating gas appliance which has a built-in circulation pump and air vent. It provides central
heating and domestic hot water. Depending on the heat capacity, three models are available with different ratings: 24 kW, 28 kW,
34kW, and 40 kW.
Model Maximum Space Heating Input Maximum DHW INPUT
NCB-24LSWE 20.0 kW 24.0 kW
NCB-28LSWE 24.0 kW 28.0 kW
NCB-34LSWE 29.0 kW 34.0 kW
NCB-40LSWE 34.0 kW 40.0 kW
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By default, the boiler assigns system priority to DHW supply.
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The NCB Series boiler has a built-in circulation pump, 3-way valve assembly, flow sensor, DHW plate heat exchanger and, a
safety valve (or relief valve). A separate heating expansion vessel is required.
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Internal freeze protection and an electronic control unit are incorporated inside the boiler. The boiler is compatible with all
brands of standalone room thermostats and various sets of relay contacts can be used with the boiler.