Navien is introducing its next-generation combi-boiler, the NCB-E. Navien’s one-unit NCB series is capable of providing a whole-house heating system while also providing the domestic hot-water output of a stand-alone tankless water heater. The NCB-E will be a rolling replacement, now with a Grundfos pump, an integral air vent, a PRV top connection, a quieter fan and a new front cover bevel design.