Navien and Noritz both appear in the provided source set through tankless water-heater facts, but this page is not a controlled head-to-head, and an apples-to-apples spec match was not verified. Navien's figures come from Navien pages, and Noritz figures come from Noritz pages. The purpose is to help compare documented claims without turning unmatched specs into a verdict.
A note on how to read this comparison
The cited facts do not place Navien and Noritz units in the same controlled test. Navien's record focuses on gas tankless positioning, ComfortFlow, and the NPE-240A2. Noritz's record includes NR98OD, EZ111DV, and EZ Series positioning. Those are different manufacturer pages with different product contexts.
A fair quote review should keep each claim attached to the source that makes it. Navien's NPE-240A2 flow values are presented by temperature rise, while Noritz's cited model facts list ranges for flow and BTU. Navien's warranty fact is attached to the NPE-240A2 page. Noritz's warranty facts are attached to NR98OD, EZ111DV, and EZ Series pages. The homeowner's job is to ask whether the contractor's proposal matches those cited records or whether another model page is needed.
Navien published specs
Navien's own residential tankless page positions the company as the #1 manufacturer of all gas tankless water heaters, condensing and non-condensing, in North America. That gives brand-position context, but the more useful detail comes from the NPE-240A2 product page.
On the NPE-240A2 page, Navien describes ComfortFlow as its exclusive built-in recirculation pump and buffer tank system. Navien also says it was the first to combine a buffer tank, recirculation pump and fine-tuned controls in a tankless water heater. For homeowners, that means ComfortFlow should be discussed as part of system design, not as a vague comfort promise.
The NPE-240A2 page lists a Uniform Energy Factor of 0.95. It lists flow rate as 11.2 GPM (42.4 l/m) at 35F rise, 8.7 GPM at 45F rise, and 5.6 GPM at 67F rise. It also lists an input range of 13,300 - 199,900 BTU/h and says the unit is field convertible between Natural Gas and Propane. Navien's cited residential warranty for the NPE-240A2 is 15 years heat exchanger, 5 years parts, 1 year labor. All of those claims should be matched to the exact Navien model in the quote.
Noritz published specs
Noritz's own NR98OD product page positions the NR tankless line as reliable and long-lasting, ideal for homes of all sizes including high hot water needs. The same cited NR98OD record lists 0.82 UEF, 0.5 to 9.8 GPM, 16,000 to 199,900 BTU, and a 12-year heat exchanger warranty. Those are Noritz's own specs for that cited model and should be treated as model-specific.
Noritz's cited EZ111DV product page provides a separate record. It lists EZ111DV at 0.98 UEF, 0.4 to 11.1 GPM, 12,800 to 199,900 BTU, natural gas, and 25 Year Warranty. That page also positions the EZ Series to cut installation time/cost when replacing storage tank units and says the series is engineered for the North American residential market. A separate Noritz EZ Series page calls the EZ Series the industry leader in tankless with an industry-leading 25 year warranty.
For quote review, the difference between NR98OD and EZ111DV matters. Both are Noritz facts, but they are not the same model record. A contractor should say which Noritz model is being proposed and should not mix NR98OD and EZ111DV facts unless the quote clearly explains why each source is relevant.
How to actually choose
Make the comparison model-specific before treating it as a real purchase decision. For Navien, the cited record supports questions about NPE-240A2 UEF, temperature-rise flow figures, input range, Natural Gas and Propane convertibility, ComfortFlow, and the residential warranty. For Noritz, the cited record supports questions about NR98OD specs, EZ111DV specs, EZ Series replacement positioning, and the stated warranty terms.
Next, ask each installer to translate those manufacturer facts into a home-specific design. The quote should identify the exact unit, fuel, installation approach, hot-water demand assumption, venting path, recirculation plan if applicable, water-quality plan, warranty handling, and local service support. The cited facts do not supply installed cost, project labor, local code requirements, or whether a given home has the right utility capacity.
If a Navien quote leans on ComfortFlow, ask how it will be configured. If a Noritz quote leans on EZ Series replacement positioning, ask what about the existing tank replacement makes that claim relevant. Ask the installer to keep manufacturer evidence, local assumptions, and warranty paperwork separated in the written proposal. The choice should come from a documented model match and a clear installation plan, not from unmatched brand claims.
Frequently asked questions
Is this a verified Navien and Noritz head-to-head?
No. This is not a controlled head-to-head, and an apples-to-apples spec match was not verified. It compares each brand's own cited manufacturer facts.
What Navien model facts are cited here?
The cited Navien product record is NPE-240A2, including ComfortFlow, UEF, flow by temperature rise, input range, fuel convertibility, and residential warranty.
What Noritz model facts are cited here?
The cited Noritz product records include NR98OD specs and EZ111DV specs, plus EZ Series positioning from Noritz pages.
Can I compare Navien GPM and Noritz GPM without context?
No. The cited Navien flow values use temperature-rise conditions, while the cited Noritz model facts list model ranges. Ask the installer to explain the sizing basis.
What should decide the final choice?
Use exact model documentation, fuel fit, installation design, recirculation needs, warranty handling, service support, and the household's hot-water demand.