Noritz NRCB Combi Boiler vs Rinnai RU199iN Tankless Water Heater
Side-by-side comparison of features, pricing, ratings, and alternatives.
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.
The Rinnai RU199iN is a condensing natural-gas tankless water heater that delivers up to 11 gallons per minute, making it ideal for large households with high hot water demands. Its condensing technology allows for increased efficiency and reduced energy consumption.
- 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
- High-efficiency condensing technology reduces energy consumption
- Delivers up to 11 gallons per minute of hot water for high-demand households
- Compact design for easy installation in residential spaces
- Durable construction for long-lasting performance
- Requires professional installation and correct sizing
- Pricing runs through installers rather than being published
- Combi units can struggle with simultaneous heavy hot water draws
- Requires natural gas connection, which may not be available in all areas
- Higher upfront cost compared to traditional tank-style water heaters
- May require additional installation costs for venting and piping
More alternatives & similar tools
Alternatives to Noritz NRCB Combi Boiler
View all →Condensing natural-gas tankless water heater for high-demand households
Alternatives to Rinnai RU199iN Tankless Water Heater
View all →High-efficiency water heating engineered for ultimate performance and reliability.
Tankless combi boiler providing home heating and continuous domestic hot water from one unit.
Tankless under‑sink RO system delivering 800 gallons per day of pure water.
The Verdict
AI-generated from listing dataThe Rinnai RU199iN is a high‑efficiency, gas‑powered tankless water heater focused on delivering hot water, while the Noritz NRCB is a wall‑mounted combi boiler that provides both space heating and hot water.
Key differences
- •Rinnai supplies only domestic hot water (up to 11 gpm); Noritz combines space heating with hot water.
- •Rinnai is a standalone water heater with known one‑time price; Noritz pricing is not disclosed and must be obtained through installers.
- •Rinnai uses condensing technology and is Energy Star certified; Noritz’s efficiency details are not provided.
- •Rinnai requires a natural‑gas line and venting; Noritz also needs professional installation and correct sizing for both heating and hot water.
- •Rinnai’s compact dimensions are specified; Noritz’s physical size is not listed.
Pricing & value
Rinnai lists a one‑time price; Noritz requires contacting installers, so cost is unknown.
Energy efficiency
Rinnai is Energy Star certified with condensing tech; Noritz provides no efficiency rating.
Flow capacity
Rinnai delivers up to 11 gpm; Noritz’s hot‑water flow is not specified.
Functionality (heating vs water only)
Noritz provides both space heating and domestic hot water; Rinnai only supplies hot water.
Installation complexity
Both need professional install, but Noritz also requires correct sizing for heating and hot water, adding complexity.
Choose Noritz NRCB Combi Boiler if…
Homes that want to replace both a boiler and water heater with one wall‑mounted unit.
Choose Rinnai RU199iN Tankless Water Heater if…
Large households needing high‑flow hot water and have natural‑gas service.
Common questions
What is the upfront cost?
Rinnai has a disclosed one‑time price; Noritz pricing must be obtained from an installer, so cost is not specified.
Can the unit provide space heating?
Only the Noritz NRCB combi boiler provides both space heating and domestic hot water; the Rinnai RU199iN supplies hot water only.
How does simultaneous hot‑water demand affect performance?
Rinnai delivers up to 11 gpm, suitable for multiple fixtures; Noritz combi units can struggle with heavy simultaneous draws, per vendor notes.