Noritz tankless water heater error codes
Japanese manufacturer of gas tankless water heaters with a long-standing US product line.
Pick your series below — Noritz code meanings are documented per series, because the same number can point to a different fault on a different generation.
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EZ Series & NCC199CDV
26 documented codes
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NCC199 & NRC111
25 documented codes
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NR50, NR66 & NR71
17 documented codes
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NR98 & NR111
25 documented codes
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NRC Series
25 documented codes
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NRCP
28 documented codes
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NRCP Eco TOUGH
28 documented codes
Codes documented on more than one Noritz series
Pick a number to see what it means on each series side by side — useful when you know the code but not the generation.
Not sure which series you own? The model-number decoder matches the number on your rating label to the right table.
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All Noritz codes in one table
| Code | Series | Error | Verdict |
|---|---|---|---|
| 10 | EZ Series & NCC199CDV | Combustion fault recorded in history | Call a pro |
| 11 | EZ Series & NCC199CDV | Ignition failure | Call a pro |
| 12 | EZ Series & NCC199CDV | Flame rod does not detect flame | Call a pro |
| 13 | EZ Series & NCC199CDV | External carbon monoxide alarm triggered | Emergency — stop |
| 15 | EZ Series & NCC199CDV | Abnormally high input temperature | Call a pro |
| 16 | EZ Series & NCC199CDV | Abnormally high output temperature | Call a pro |
| 20 | EZ Series & NCC199CDV | Heat exchanger high limit switch triggered | Call a pro |
| 21 | EZ Series & NCC199CDV | Burner chamber high limit switch triggered | Call a pro |
| 30 | EZ Series & NCC199CDV | Air thermistor fault | Part replacement |
| 31 | EZ Series & NCC199CDV | Cold water thermistor fault | Part replacement |
| 32 | EZ Series & NCC199CDV | Hot water thermistor fault | Part replacement |
| 33 | EZ Series & NCC199CDV | Heat exchanger outlet thermistor fault | Part replacement |
| 35 | EZ Series & NCC199CDV | Exhaust thermistor fault | Call a pro |
| 36 | EZ Series & NCC199CDV | Heat exchanger inlet thermistor fault | Part replacement |
| 61 | EZ Series & NCC199CDV | Fan motor fault | Call a pro |
| 65 | EZ Series & NCC199CDV | Main water servo fault | Part replacement |
| 66 | EZ Series & NCC199CDV | Bypass water servo fault | Part replacement |
| 70 | EZ Series & NCC199CDV | Circuit board fault | Part replacement |
| 71 | EZ Series & NCC199CDV | Gas valve drive circuit fault | Call a pro |
| 72 | EZ Series & NCC199CDV | Flame rod circuit fault | Call a pro |
| 73 | EZ Series & NCC199CDV | Circuit board setting fault | Call a pro |
| 76 | EZ Series & NCC199CDV | Multi-system communication error | Part replacement |
| 90 | EZ Series & NCC199CDV | Combustion fault, unit shuts off | Call a pro |
| 94 | EZ Series & NCC199CDV | Exhaust temperature too high | Call a pro |
| 760 | EZ Series & NCC199CDV | Remote controller communication fault | Part replacement |
| C1 | EZ Series & NCC199CDV | Service reminder | DIY fix |
| 10 | NCC199 & NRC111 | Combustion fault, BTU drop | Call a pro |
| 11 | NCC199 & NRC111 | Ignition failure | Call a pro |
| 12 | NCC199 & NRC111 | Flame rod does not detect flame | Call a pro |
| 14 | NCC199 & NRC111 | Thermal fuse triggered | Call a pro |
| 16 | NCC199 & NRC111 | Abnormally high output temperature | Call a pro |
| 20 | NCC199 & NRC111 | High limit switch triggered | Call a pro |
| 29 | NCC199 & NRC111 | Neutralizer or water level electrode fault | DIY fix |
| 30 | NCC199 & NRC111 | Air inlet thermistor fault | Part replacement |
| 31 | NCC199 & NRC111 | Inlet thermistor fault | Part replacement |
| 32 | NCC199 & NRC111 | Outlet thermistor fault | Part replacement |
| 33 | NCC199 & NRC111 | Heat exchanger thermistor fault | Part replacement |
| 59 | NCC199 & NRC111 | Heat exchanger flow fault | DIY fix |
| 61 | NCC199 & NRC111 | Fan motor fault | Call a pro |
| 65 | NCC199 & NRC111 | Main flow control valve fault | Part replacement |
| 66 | NCC199 & NRC111 | Bypass flow control valve fault | Part replacement |
| 70 | NCC199 & NRC111 | Circuit board fault | Part replacement |
| 71 | NCC199 & NRC111 | Gas solenoid valve drive circuit fault | Call a pro |
| 72 | NCC199 & NRC111 | Flame rod circuit fault | Call a pro |
| 73 | NCC199 & NRC111 | Circuit board setting fault | Call a pro |
| 90 | NCC199 & NRC111 | Combustion fault | Call a pro |
| 92 | NCC199 & NRC111 | Neutralizer life cycle warning | DIY fix |
| 93 | NCC199 & NRC111 | Neutralizer life cycle has ended | DIY fix |
| 99 | NCC199 & NRC111 | Combustion fault, unit shuts off | Call a pro |
| 760 | NCC199 & NRC111 | Remote controller communication fault | Part replacement |
| F76 | NCC199 & NRC111 | Multi-system communication error | Part replacement |
| 10 | NR50, NR66 & NR71 | Combustion fault, BTU drop | Call a pro |
| 11 | NR50, NR66 & NR71 | Ignition failure | Call a pro |
| 12 | NR50, NR66 & NR71 | Flame rod does not detect flame | Call a pro |
| 14 | NR50, NR66 & NR71 | Thermal fuse triggered | Call a pro |
| 16 | NR50, NR66 & NR71 | Abnormally high output temperature | Call a pro |
| 20 | NR50, NR66 & NR71 | High limit switch triggered | Call a pro |
| 31 | NR50, NR66 & NR71 | Inlet thermistor fault | Part replacement |
| 32 | NR50, NR66 & NR71 | Outlet thermistor fault | Part replacement |
| 59 | NR50, NR66 & NR71 | Heat exchanger flow fault | DIY fix |
| 61 | NR50, NR66 & NR71 | Fan motor fault | Call a pro |
| 70 | NR50, NR66 & NR71 | Circuit board fault | Part replacement |
| 71 | NR50, NR66 & NR71 | Gas solenoid valve drive circuit fault | Call a pro |
| 72 | NR50, NR66 & NR71 | Flame rod circuit fault | Call a pro |
| 73 | NR50, NR66 & NR71 | Circuit board setting fault | Call a pro |
| 90 | NR50, NR66 & NR71 | Combustion fault | Call a pro |
| 99 | NR50, NR66 & NR71 | Combustion fault, unit shuts off | Call a pro |
| 760 | NR50, NR66 & NR71 | Remote controller communication fault | Part replacement |
| 10 | NR98 & NR111 | Combustion fault, BTU drop | Call a pro |
| 11 | NR98 & NR111 | Ignition failure | Call a pro |
| 12 | NR98 & NR111 | Flame rod does not detect flame | Call a pro |
| 14 | NR98 & NR111 | Thermal fuse triggered | Call a pro |
| 16 | NR98 & NR111 | Abnormally high output temperature | Call a pro |
| 20 | NR98 & NR111 | High limit switch triggered | Call a pro |
| 21 | NR98 & NR111 | Pressure switch triggered | Call a pro |
| 30 | NR98 & NR111 | Air inlet thermistor fault | Part replacement |
| 31 | NR98 & NR111 | Inlet thermistor fault | Part replacement |
| 32 | NR98 & NR111 | Outlet thermistor fault | Part replacement |
| 33 | NR98 & NR111 | Heat exchanger thermistor fault | Part replacement |
| 41 | NR98 & NR111 | Flow sensor fault | Part replacement |
| 56 | NR98 & NR111 | Multi-system CCP valve fault | Part replacement |
| 59 | NR98 & NR111 | Heat exchanger flow fault | DIY fix |
| 61 | NR98 & NR111 | Fan motor fault | Call a pro |
| 65 | NR98 & NR111 | Main flow control valve fault | Part replacement |
| 66 | NR98 & NR111 | Bypass flow control valve fault | Part replacement |
| 70 | NR98 & NR111 | Circuit board fault | Part replacement |
| 71 | NR98 & NR111 | Gas solenoid valve drive circuit fault | Call a pro |
| 72 | NR98 & NR111 | Flame rod circuit fault | Call a pro |
| 73 | NR98 & NR111 | Circuit board setting fault | Call a pro |
| 90 | NR98 & NR111 | Combustion fault | Call a pro |
| 99 | NR98 & NR111 | Combustion fault, unit shuts off | Call a pro |
| 760 | NR98 & NR111 | Remote controller communication fault | Part replacement |
| F76 | NR98 & NR111 | Multi-system communication error | Part replacement |
| 11 | NRC Series | Ignition failure | Call a pro |
| 12 | NRC Series | Flame rod does not detect flame | Call a pro |
| 14 | NRC Series | Thermal fuse triggered | Call a pro |
| 16 | NRC Series | Abnormally high output temperature | Call a pro |
| 20 | NRC Series | High limit switch triggered | Call a pro |
| 29 | NRC Series | Condensate container clogged | DIY fix |
| 30 | NRC Series | Air thermistor fault | Part replacement |
| 31 | NRC Series | Cold water thermistor fault | Part replacement |
| 32 | NRC Series | Hot water thermistor fault | Part replacement |
| 33 | NRC Series | Heat exchanger thermistor fault | Part replacement |
| 35 | NRC Series | Exhaust thermistor fault | Call a pro |
| 51 | NRC Series | Gas solenoid valve failure | Call a pro |
| 61 | NRC Series | Fan motor fault | Call a pro |
| 70 | NRC Series | Circuit board fault | Part replacement |
| 71 | NRC Series | Gas solenoid valve drive circuit fault | Call a pro |
| 72 | NRC Series | Flame rod circuit fault | Call a pro |
| 73 | NRC Series | Circuit board setting fault | Call a pro |
| 76 | NRC Series | Display window communication fault | Part replacement |
| 90 | NRC Series | Air flow or combustion fault | Call a pro |
| 91 | NRC Series | Improper gas type | Call a pro |
| 94 | NRC Series | Exhaust temperature too high | Call a pro |
| 99 | NRC Series | Combustion fault, unit locked | Call a pro |
| 760 | NRC Series | Remote controller communication fault | Part replacement |
| C1 | NRC Series | Scale build-up in the heat exchanger | DIY fix |
| CF | NRC Series | Scale lockout | Call a pro |
| Er11 | NRCP | Ignition failure | Call a pro |
| Er12 | NRCP | Flame loss | Call a pro |
| Er16 | NRCP | Overheating | DIY fix |
| Er20 | NRCP | Water high limit switch fault | DIY fix |
| Er29 | NRCP | Air pressure switch fault | Call a pro |
| Er31 | NRCP | Cold water thermistor open or short | Part replacement |
| Er32 | NRCP | Hot water thermistor open or short | Part replacement |
| Er33 | NRCP | Heat exchanger thermistor open or short | Part replacement |
| Er35 | NRCP | Exhaust thermistor open or short | Call a pro |
| Er38 | NRCP | Circuit board memory error | Part replacement |
| Er39 | NRCP | Flame detected after the gas valve closed | Call a pro |
| Er40 | NRCP | Gas leakage | Emergency — stop |
| Er41 | NRCP | Fan speed fault or exhaust blockage | Call a pro |
| Er43 | NRCP | Burner high limit switch fault | Call a pro |
| Er44 | NRCP | Possible pump failure | Part replacement |
| Er45 | NRCP | Water leak detected | Call a pro |
| Er46 | NRCP | Low recirculation flow | DIY fix |
| Er60 | NRCP | Hot water temperature abnormality | Call a pro |
| Er61 | NRCP | Fan RPM sensor fault | Call a pro |
| Er65 | NRCP | Water control valve fault | Part replacement |
| Er66 | NRCP | Water mixing valve fault | Part replacement |
| Er67 | NRCP | Gas modulation assembly fault | Call a pro |
| Er70 | NRCP | Circuit board fault | Part replacement |
| Er72 | NRCP | Flame detected before the gas valve opens | Call a pro |
| Er73 | NRCP | DIP switch setting fault | Call a pro |
| Er76 | NRCP | Control panel communication error | Part replacement |
| Er78 | NRCP | Quick Connect communication error | Part replacement |
| Er94 | NRCP | Exhaust overheating | Call a pro |
| Er11 | NRCP Eco TOUGH | Ignition failure | Call a pro |
| Er12 | NRCP Eco TOUGH | Flame loss | Call a pro |
| Er16 | NRCP Eco TOUGH | Overheating | DIY fix |
| Er20 | NRCP Eco TOUGH | High limit switch fault | DIY fix |
| Er29 | NRCP Eco TOUGH | Air pressure switch fault | Call a pro |
| Er31 | NRCP Eco TOUGH | Cold water thermistor open or short | Part replacement |
| Er32 | NRCP Eco TOUGH | Hot water thermistor open or short | Part replacement |
| Er33 | NRCP Eco TOUGH | Heat exchanger thermistor open or short | Part replacement |
| Er35 | NRCP Eco TOUGH | Exhaust thermistor open or short | Call a pro |
| Er38 | NRCP Eco TOUGH | Circuit board memory error | Part replacement |
| Er39 | NRCP Eco TOUGH | False flame detection | Call a pro |
| Er40 | NRCP Eco TOUGH | Gas leakage | Emergency — stop |
| Er41 | NRCP Eco TOUGH | Fan speed error | Call a pro |
| Er42 | NRCP Eco TOUGH | Loose jumper | Part replacement |
| Er43 | NRCP Eco TOUGH | Burner high limit switch fault | Call a pro |
| Er44 | NRCP Eco TOUGH | Recirculation abnormality | DIY fix |
| Er45 | NRCP Eco TOUGH | Water leak detected | Call a pro |
| Er60 | NRCP Eco TOUGH | Hot water temperature abnormality | Call a pro |
| Er61 | NRCP Eco TOUGH | Fan RPM sensor fault | Call a pro |
| Er65 | NRCP Eco TOUGH | Water adjustment valve fault | Part replacement |
| Er66 | NRCP Eco TOUGH | Mixing valve fault | Part replacement |
| Er67 | NRCP Eco TOUGH | Gas modulation assembly fault | Call a pro |
| Er70 | NRCP Eco TOUGH | Circuit board processor error | Part replacement |
| Er72 | NRCP Eco TOUGH | Flame detected before ignition | Call a pro |
| Er73 | NRCP Eco TOUGH | DIP switch setting fault | Call a pro |
| Er76 | NRCP Eco TOUGH | Display panel communication error | Part replacement |
| Er78 | NRCP Eco TOUGH | Quick Connect communication error | Part replacement |
| Er94 | NRCP Eco TOUGH | Exhaust overheating | Call a pro |
Each code links to a full page: what the manual says for that exact series, the likely fix, and what it should cost.