The ENERGY STAR rated NRC661, Noritz’s efficient condensing model with a half inch gas line. Featuring the same energy-saving condensing technology as the rest of the Noritz eco-TOUGH™ Series of gas-fired residential tankless water heaters, the NRC661 has an Energy Factor of 0.89 for NG and LP models. These ratings are nearly 10 points higher than that of a comparably sized, conventional tankless unit, and approximately 30 points higher than a standard, tank-type gas-fired water heater.

Technical Literature

Technical Specs


Heat Exchanger Warranty (w/out Recirculation) 12 Years
Heat Exchanger Warranty (w/Recirculation) 3 Years
Parts Warranty 5 Years
Labor Warranty 1 Year

For detailed warranty terms and conditions please refer to the Noritz warranty page

Part #: SAD6633-B

O-Ring - High Temp P3


Part #: SAD6635-B

O-Ring - High Temp P9


Part #: 7287909-B

Wire Clamp - Nylon (replaced 7287909)


Part #: SAE6198

Cord bushing SR-5P-4 (Replaced with ETPA073)

Replaced with ETPA073
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