Navien NPE-240A2 vs Noritz NRCB Combi Boiler

The Navien NPE-240A2 delivers on-demand hot water using condensing technology, which captures waste heat to boost efficiency. Its integrated 2.5-gallon buffer tank smooths temperature swings, ensuring consistent water temperature even during simultaneous usage. Designed for residential and light commercial settings, this unit offers a high flow rate of up to 9.5 GPM at a 35°F temperature rise while meeting Energy Star standards. The compact footprint and low NOx emissions make it a clean, space-saving solution for modern homes.

The NRCB series is Noritz's combination boiler, which handles both space heating and domestic hot water from a single wall-mounted appliance. That combination is the point: instead of a boiler for the radiators and a separate tank water heater, one unit does both, freeing the floor space a tank would occupy and removing the standby heat loss that comes with keeping a tank hot around the clock. Because it is tankless on the hot water side, supply is continuous rather than limited by tank capacity, so back-to-back showers do not run out. Noritz is a tankless water heating specialist with residential and commercial ranges, and supports the NRCB with a sizing guide, plumbing diagrams, BIM and Revit files, installer training, a PROCard programme and installer and servicer locators.

• Endless hot water supply
• High energy efficiency reduces utility bills
• Buffer tank eliminates temperature swings
• Compact size fits tight installation spaces

• Replaces two appliances with one wall-mounted unit
• Continuous hot water with no tank to run out
• Frees the floor space a tank would take
• Strong installer documentation and training infrastructure

• Requires professional gas line installation
• Higher upfront cost than traditional tank heaters
• No built-in smart or app connectivity

• Requires professional installation and correct sizing
• Pricing runs through installers rather than being published
• Combi units can struggle with simultaneous heavy hot water draws