Noritz Error Codes & Diagnostic Codes

Updated October 13, 2026 · by Aurora Star Tech Inc.

Noritz error codes and diagnostic codes: look up a code to see what it means, the likely causes and the steps to fix it.

Noritz error codes by equipment type

Noritz Tankless Water Heater error codes

Code	Meaning
06	Low recirculation flow (warning only)
10	Abnormal combustion (NRCR, gas supply related)
11	Ignition failure (no flame detected)
12	Flame loss (repeated)
14	Thermal fuse failure
16	Abnormally high outlet temperature
20	High limit switch tripped
29	Condensate collector water level abnormal
061	Recirculation abnormality (sub-code of 06)
062	Recirculation abnormality (sub-code of 06)
63	Recirculation abnormality (no recirculation flow)
65	Main water control servo abnormality
66	Bypass water control servo abnormality
73	Circuit board setting abnormality
90	Combustion abnormality
91	Gas conversion not done correctly
901	Combustion abnormality (sub-code of 90)
902	Combustion abnormality (sub-code of 90)
C1#	Descaling reminder (C11-C19)
F76	Multi-system communication error

Find codes by Noritz model

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Noritz error codes by equipment type

Noritz Tankless Water Heater error codes

Find codes by Noritz model

Noritz EZ

Noritz NRC/NRCP

Noritz CDV

Noritz NRCR

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