Noritz tankless water heater error codes
65 codes for EZ, NRCR, EZTR40, NRC661A/NRC711, NRC661, NRC98/NRC111/NERC, NRC (2013), NRC111 (2009), NRCP, NR98/NR83/NR71DVC, NR501/NR662/NER66, NR (2009–2013), Field Manual (models not listed), each with the wording and page from Noritz's manuals.
All Noritz codes
Meanings are quoted from Noritz's manuals. The "Who" column is our reading of the manual's remedy: whether an owner can do the first checks, or the fix belongs to a licensed technician.
| Code | Manual meaning | Series | Who | Source |
|---|---|---|---|---|
| 05 | “Service warning” The guide says the heater has an automatic service reminder, to contact the nearest Noritz agent, and to reset the display only after the heater is flushed and/or the water treatment device is serviced (NRC83/NRC98 Owner's Guide Rev. 03/13, p. 27). Field Manual KS-11-0004, a training document for service technicians that also covers NR981 models, calls it “Service Reminder” and says the reminder is optional and off by default (pp. 26, 32). | NRC (2013) | Technician | NRC83/NRC98 guide 03/13 p. 27; Field Manual KS-11-0004 p. 26 |
| 06 | “Recirculation abnormality” NRCR models only. The 2025 guide lists it as 06, 061 and 062, with checks of the return line filter and the crossover valve's filter (EZ/NRCR Owner's Guide Rev. 10/25, p. 31). The 2021 guide uses 06 for “Low recirculation flow (Only warning indication. The water heater will continue to operate.)”, with only the return line filter check (NRCR Owner's Guide Rev. 04/21, p. 19); NRCR Technical Sheet FPHK081 also calls 06 “Low recirculation flow”, a warning only (p. 1). | NRCR | Owner checks, then technician | EZ/NRCR guide 10/25 p. 31; EZ/NRCR guide 01/24 p. 25 |
| 10 | “Combustion abnormality” Listed only in Noritz technical documents for service technicians. The EZ sheets say 10 is kept only in the error code history; the 2025 sheet adds that it occurs only at high fan speed, when a blockage is detected and the fan speed is limited (EZ Technical Sheet FPFK081, p. 1). Field Manuals: “Combustion Abnormality”, in tables that do not say which models show it. | EZ, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZ tech sheet FDAK080 p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 11 | “Ignition failure” What to check “Ignition error” in EZ Owner's Guide SBB80T9-2 (p. 28) and in the EZTR40, NRC, NERC, NR and NER66OD guides. NRCP heaters show Er:11, “Ignition has Failed 10 (Ten) Times” (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39). Technical sheets: “Ignition failure (Initial flame fault detection)”. | EZ, NRCR, EZTR40, NRC661A/NRC711, NRC661, NRC98/NRC111/NERC, NRC (2013), NRC111 (2009), NRCP, NR98/NR83/NR71DVC, NR501/NR662/NER66, NR (2009–2013) | Owner checks, then technician | EZ/NRCR guide 10/25 p. 31; EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25; NRC98 guide 01/17 p. 28; NRC83/NRC98 guide 03/13 p. 26; NRC111 guide 09/09 p. 27; NRCP1112/NRCP982 guide p. 39; NR98 guide 11/20 p. 26; NR501/NR662 guide p. 24; NR50/NR66/NR71 guide p. 26 |
| 12 | “Flame Rod does not detect flame (Flame fault detection)” Listed only in Noritz technical documents for service technicians. Also shown as 12-1 or 12-2 (2025 EZ sheet) and as 121 or 122 (2024 EZ sheet; EZTR40, NRC661A/NRC711 and NRC661 sheets, where the remote shows 12). EZ Installation Manual Rev. 10/25 calls 121 and 122 “Flame loss” (p. 61). Field Manuals: “Flame Rod Does Not Detect Flame (Secondary Flame Fault Detection)”. NRCP data sheets list Er12 as “Flame Loss” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34; EZ install manual 10/25 p. 61 |
| 13 | “External CO detector triggered” Listed only in Noritz technical documents for service technicians. 2021 and 2024 EZ sheets: “External CO alarm triggered”. Also shown as 13-6 (2025 sheet) or 136 (2024 sheet). EZ Installation Manual Rev. 10/25 shows “External CO Alarm Triggered 13” in its test of a connected CO alarm (p. 50). | EZ | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZ install manual 10/25 p. 50 |
| 14 | “Thermal Fuse triggered” Listed only in Noritz technical documents for service technicians. Not on the 2021 EZ sheets. EZTR40, NRC661A/NRC711 and NRC661 sheets: “Overheat Prevention Device (Thermal Fuse) triggered”, reset by disconnecting and reconnecting power (EZTR40 Technical Sheet EXSK072, p. 1). Field Manuals: “Overheat Cutoff Fuse”. | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 15 | “Abnormally high input temperature” Listed only in Noritz technical documents for service technicians. Only on the 2021 EZ sheets. | EZ | Technician | EZ tech sheet FABK080 p. 1; EZ tech sheet FDAK080 p. 1 |
| 16 | “Abnormally high output temperature” Listed only in Noritz technical documents for service technicians. Also shown as 16-# (2025 EZ sheet), 16# (2024 EZ sheet) or 161, 162 and 163 (EZTR40, NRC661A/NRC711 and NRC661 sheets, where the remote shows 16). Field Manuals: “Abnormally High Output Temperature”. On NRCP heaters Er16 is a different entry, “Overheating HEX and DHW Temperature Sensor” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2; NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 20 | “High Limit Switch triggered” Listed only in Noritz technical documents for service technicians. The EZ sheets say it may be caused by scale build-up in the heat exchanger and is reset by disconnecting and reconnecting power (EZ Technical Sheet FPFK081, p. 1). 2024 EZ sheet: “High Limit Switch -Heat Exchanger triggered”; 2021 EZ sheets: “High Limit Switch -Primary Heat Exchanger triggered”. Field Manuals: “High Limit Switch”. On NRCP heaters Er20 reads “Water High Limit Switch Abnormality” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2; NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 21 | “High Limit Switch -Burner Chamber triggered” Listed only in Noritz technical documents for service technicians. Only on the 2021 EZ sheet FABK080, which says to contact the nearest Noritz agent to reset it (EZ Technical Sheet FABK080, p. 1). The Field Manuals use 21 for a different entry, “Pressure Switch Abnormality”, with remedies that end “(For N-1321M-ASME)”, a model this table does not cover (Field Manual KS-11-0004, p. 26; Field Manual June 2011, p. 34). | EZ | Technician | EZ tech sheet FABK080 p. 1 |
| 29 | “Clogging of condensate trap or drain pipe” What to check Other models use 29 for other faults. NRCP (Er:29): “Air Pressure Switch Abnormality” (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39; NRCP111/NRCP98 Owner's Guide Rev. 05/19, p. 34). NRC111 Owner's Guide Rev. 09/09: “Clogging of neutralizer” (p. 27). EZ technical sheets: “External Condensate Pump abnormality”, shown only if an external condensate pump is interlocked with the heater (EZ Technical Sheet FPFK081, p. 1), and “Condensate pump abnormality (Only if connected to the water heater)” (EZ Technical Sheet FHCK080, p. 1). EZTR40, NRC661A/NRC711 and NRC661 sheets: “Condensate Container clogging” (EZTR40 Technical Sheet EXSK072, p. 1). Field Manual KS-11-0004: “Neutralizer Water Level Electrode Abnormality” (p. 26). | EZTR40, NRC661A/NRC711, NRC661, NRC98/NRC111/NERC, NRC (2013) | Owner checks, then technician | NRC98 guide 01/17 p. 28; NRC111 guide 01/17 p. 28; NERC98DV guide p. 28; NERC11DV guide p. 28; NRC83/NRC98 guide 03/13 p. 26; NRC1111 guide p. 27; EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25 |
| 30 | “Thermistor-Air abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 30-1 or 30-2 (2025 EZ sheet) and 301 or 302 (2024 EZ sheet; EZTR40, NRC661A/NRC711 and NRC661 sheets, where 301 is an open circuit and 302 a short circuit). The Field Manuals use 30 for “Freeze Protection Thermostat” (Field Manual KS-11-0004, p. 26; Field Manual June 2011, p. 34). | EZ, EZTR40, NRC661A/NRC711, NRC661 | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1 |
| 31 | “Thermistor-Cold Water abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 31-1, 31-2, 311 or 312. NRCP: Er31 “Cold Water Inlet Thermistor Open or Short Circuit” (NRCP1112/NRCP982) or “Cold Water Thermistor Open or Short” (NRCP111/NRCP98). Field Manuals: “Inlet Thermistor Abnormality”. | EZ, EZTR40, NRC661A/NRC711, NRC661, NRCP, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 32 | “Thermistor-Hot Water abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 32-1, 32-2, 321 or 322; the EZTR40, NRC661A/NRC711 and NRC661 sheets add 323, “Detection temperature abnormality”. NRCP: Er32 “DHW Temperature Sensor Open or Short” (NRCP1112/NRCP982) or “Hot Water Thermistor Open or Short” (NRCP111/NRCP98). Field Manuals: “Outlet Thermistor Abnormality”. | EZ, EZTR40, NRC661A/NRC711, NRC661, NRCP, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 33 | “Thermistor-Heat Exchanger Outlet abnormality” Listed only in Noritz technical documents for service technicians. 2021 EZ sheets: “Thermistor-Primary Heat Exchanger Outlet abnormality”. EZTR40, NRC661A/NRC711 and NRC661 sheets: “Thermistor - Heat Exchanger abnormality” (331, 332). NRCP: Er33 “Heat Exchanger Thermistor Open or Short Circuit”. Field Manual KS-11-0004: “Heat Exchanger Thermistor Abnormailty” (as printed). Field Manual June 2011 uses 33 for “Heat Exchanger Thermostat” (p. 34). | EZ, EZTR40, NRC661A/NRC711, NRC661, NRCP, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2; Field Manual KS-11-0004 p. 26 |
| 35 | “Thermistor-Exhaust abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 35-1 to 35-4 or 351 to 354. NRCP: Er35 “Exhaust thermistor open or short circuit” (NRCP1112/NRCP982) or “Exhaust Thermistor Open or Short” (NRCP111/NRCP98). Field Manual KS-11-0004: “Exhaust Thermistor Abnormality”. | EZ, EZTR40, NRC661A/NRC711, NRC661, NRCP, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2; Field Manual KS-11-0004 p. 26 |
| 36 | “Thermistor-Primary Heat Exchanger Inlet abnormality” Listed only in Noritz technical documents for service technicians. Only on the 2021 EZ sheets. | EZ | Technician | EZ tech sheet FABK080 p. 1; EZ tech sheet FDAK080 p. 1 |
| 38 | “Abnormal Operation; Memory Error on the PCB” Listed only in Noritz technical documents for service technicians. Shown as Er38. NRCP111/NRCP98 sheet: “Abnormal Operation; Memory Error on the Circuit Board”. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 39 | “False Flame Detection” Listed only in Noritz technical documents for service technicians. Shown as Er39. NRCP111/NRCP98 sheet: “Flame detected after gas valve closure”. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 40 | “Gas Leakage is Detected in 10 Minutes, or three times within One Hour (Greater than 5 Seconds Each Time)” Shown as Er:40. The guide's first instruction: if you smell gas, stop, follow the gas safety instructions on page 4 and call a qualified service technician or the gas utility; Er.40 is a hard lockout (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39). Technical data sheets: “Gas Leakage”. | NRCP | Technician | NRCP1112/NRCP982 guide p. 39; NRCP111/NRCP98 guide p. 34; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 41 | “Flow Sensor Abnormality” Listed only in Noritz technical documents for service technicians; the Field Manual tables do not say which models show it. NRCP heaters use Er41 for a different entry: “Fan Speed Error” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2) or “Fan Speed Abnormality (Exhaust Blockage)” (NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). The EZ/NRCR Owner's Guide Rev. 10/25 mentions 41 only in its instructions for draining the heater, where it says 11 or 41 may appear and is not a malfunction (p. 25). | Field Manual (models not listed) | Technician | Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 42 | “Water Flow Sensor (Recirculation) abnormality” Listed only in Noritz technical documents for service technicians. NRCR models only. | NRCR | Technician | NRCR tech sheet FPHK081 p. 1 |
| 43 | “Burner High Limit Switch Abnormality” Listed only in Noritz technical documents for service technicians. Shown as Er43. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 44 | “Recirculation Abnormality” Shown as Er:44. Checks: recirculation loop length within specification, the return line filter and the pump operation (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39). The owner's part is the filter: the same guide's maintenance section covers cleaning the cold water inlet filter and recirculation water filter (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 36), while its safety section says not to service the heater yourself (p. 6). NRCP111/NRCP98 Owner's Guide Rev. 05/19 uses Er:44 for “Possible pump failure”, with the single action “Check pump.” (p. 34). | NRCP | Owner checks, then technician | NRCP1112/NRCP982 guide p. 39; NRCP1112/NRCP982 data sheet p. 2 |
| 45 | “Water leakage is detected in water heater.” Shown as Er:45. The owner's part is pressing the Power button to clear the code; the next check, “Check for the water in the bottom of the heater inside the case.”, is inside the cabinet, and the action ends: “If you have confirmed the water leak, the water valve/gas valve closes and contact the installer or Noritz America Technical Support for assistance.” (NRCP1112/NRCP982 Owner's Guide Rev. 05/19, p. 39). The data sheets for service technicians call it “Water Leak” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2). | NRCP | Owner checks, then technician | NRCP1112/NRCP982 guide p. 39; NRCP111/NRCP98 guide p. 34 |
| 46 | “Low recirculation flow” Shown as Er 46, on NRCP111 and NRCP98 models only. Checks: return and cold water filters, recirculation loop length, pump operation and the recirculation setting (NRCP111/NRCP98 Owner's Guide Rev. 05/19, p. 34). The owner's part is the filters, covered in the same guide's maintenance section (NRCP111/NRCP98 Owner's Guide Rev. 05/19, p. 31). | NRCP | Owner checks, then technician | NRCP111/NRCP98 guide p. 34; NRCP111/NRCP98 data sheet p. 2 |
| 50 | “Extended Continuous Flow Detected” Listed only in Noritz technical documents for service technicians. The sheets say it is kept only in the error code history, does not indicate a water heater malfunction and appears when flow is detected for 24 hours in a row; the remedy column says to check whether any water is leaking (EZ Technical Sheet FPFK081, p. 1). | EZ | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1 |
| 51 | “Failure of Gas Solenoid Valve (or Gas Solenoid Valve drive circuit abnormality)” Listed only in Noritz technical documents for service technicians. Also shown as 511, with 51 on the remote. Field Manual KS-11-0004: “Gas Solenoid Value Error” (as printed). | EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26 |
| 56 | “CCP Valve Abnormality” Listed only in Noritz technical documents for service technicians; the Field Manual tables do not say which models show it. The remedy refers to CCP valves working with a System Controller. | Field Manual (models not listed) | Technician | Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 59 | “Combustion Abnormality” Listed only in Noritz technical documents for service technicians; the Field Manual tables do not say which models show it. Remedies: flue blockage and gas pressure. | Field Manual (models not listed) | Technician | Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 60 | “Hot Water Temperature Abnormality” Listed only in Noritz technical documents for service technicians. Shown as Er60. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 61 | “Fan Motor abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 61-1 or 61-4 (2025 EZ sheet), 611 or 614 (2024 EZ sheet) and 611, 612 or 614 (EZTR40, NRC661A/NRC711 and NRC661 sheets, where the remote shows 61). On NRCP heaters Er61 reads “RPM Sensor” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2; NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 63 | “Recirculation abnormality (No recirculation flow)” What to check Among NRCR guides only the 2021 edition lists 63 (NRCR Owner's Guide Rev. 04/21, p. 19); the 2024 and 2025 guides give the same checks under 06 (EZ/NRCR Owner's Guide Rev. 10/25, p. 31). NRCR Technical Sheet FPHK081: “Recirculation Abnormality (No recirculation flow)”, with pump checks (p. 1). The Field Manuals list 63 as “Recirculation Pump Error” in tables that do not say which models show it (Field Manual KS-11-0004, p. 26; Field Manual June 2011, p. 34). | NRCR | Owner checks, then technician | NRCR guide 04/21 p. 19; NRCR tech sheet FPHK081 p. 1 |
| 65 | “Water Servo abnormality” Listed only in Noritz technical documents for service technicians. 2021 EZ sheets: “Water Servo-Main abnormality”. Field Manuals: “Main Water Control Valve”. On NRCP heaters Er65 reads “Water Adjustment Valve Abnormality” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2) or “Water Control Valve Abnormality” (NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). | EZ, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 66 | “Water Servo-Bypass abnormality” Listed only in Noritz technical documents for service technicians. Among EZ documents, only the 2021 sheets list it. Field Manuals: “Bypass Water Control Valve”. On NRCP heaters Er66 reads “Mixing Valve Abnormality” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2) or “Water Mixing Valve Abnormality” (NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). | EZ, Field Manual (models not listed) | Technician | EZ tech sheet FABK080 p. 1; EZ tech sheet FDAK080 p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 67 | “AGM Abnormality” Listed only in Noritz technical documents for service technicians. Shown as Er67. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 70 | “Circuit Board abnormality” Listed only in Noritz technical documents for service technicians. Also shown as 70 followed by a digit (70-#, 70# or 70*). NRCP: Er70 “Micom Error on PCB Abnormality” (NRCP1112/NRCP982) or “Circuit Board Abnormality” (NRCP111/NRCP98). | EZ, EZTR40, NRC661A/NRC711, NRC661, NRCP, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 71 | “Gas Valve drive circuit abnormality” Listed only in Noritz technical documents for service technicians. Also shown with a third digit (71-1, 71-2, 71-4; 711, 712, 714; 71#). EZTR40, NRC661A/NRC711 and NRC661 sheets: “Gas Solenoid Valve drive circuit abnormality; Circuit Board abnormality”. Field Manuals: “Gas Solenoid Valve Abnormality”. | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 72 | “Flame Rod circuit abnormality” Listed only in Noritz technical documents for service technicians. The sheets describe it as detection of flame when no flame is present. Field Manuals: “Flame Rod Abnormality”. On NRCP heaters Er72 reads “Flame Detected before Ignite Abnormality” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2) or “Flame detected before gas valve opens” (NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2), and the NRCP1112/NRCP982 Owner's Guide Rev. 05/19 names Er.72 only in its list of hard-lockout codes (p. 39). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 73 | “Circuit Board setting abnormality (Improper Maintenance Writers settings or gas type setting, etc.)” Listed only in Noritz technical documents for service technicians. The 2025 EZ sheet says it appears when a connector is plugged in or unplugged with the power on and is reset by disconnecting and reconnecting power (EZ Technical Sheet FPFK081, p. 1). EZ Installation Manual Rev. 10/25 says the heater stops with 73 or 731 if a required vent setting is not selected (p. 22); EZTR40 Installation Manual Rev. 11/20 says changing the DIP switch with power connected brings up 733 (p. 12). 2021 EZ sheets: “(Improper Maintenance Writers Settings, DIP Switch Settings, etc.)”. EZTR40, NRC661A/NRC711 and NRC661 sheets: 731, 733 and 734. Field Manuals: “Improper Circuit Board Setting”. On NRCP heaters Er73 reads “DIP Switch Setting Abnormality” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34; EZ install manual 10/25 p. 22; EZTR40 install manual p. 12 |
| 74 | “BLE connection error” Listed only in Noritz technical documents for service technicians. Kept only in the error code history (EZ Technical Sheet FPFK081, p. 1). | EZ | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1 |
| 76 | “Communication Error between Front Panel and Main PCB” Listed only in Noritz technical documents for service technicians. Shown as Er76. NRCP111/NRCP98 sheet: “Communication Error between Circuit Board and Control Panel”. On 2021 EZ heaters set for a common duct the multi-system error shows as 76 (EZ Technical Sheet FABK080, p. 1), see F76; on EZTR40, NRC661A/NRC711 and NRC661 heaters the remote shows 76 for 768. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| F76 | “Multi-system communication error” Listed only in Noritz technical documents for service technicians. EZ Technical Sheet FABK080 prints (F)76 and says 76 is displayed only when a common duct is set (p. 1). Field Manuals: (F) 76 “Multi-System Communication Error”. | EZ, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZ tech sheet FDAK080 p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 78 | “Cascade Communication Error” Listed only in Noritz technical documents for service technicians. Shown as Er78. NRCP111/NRCP98 sheet: “Communication Error (Quick Connect)”. | NRCP | Technician | NRCP1112/NRCP982 data sheet p. 2; NRCP111/NRCP98 data sheet p. 2 |
| 79 | “Circuit Board abnormality” Listed only in Noritz technical documents for service technicians. NRCR models only; the remedy column names a failure of the circuit board's pump control circuit. | NRCR | Technician | NRCR tech sheet FPHK081 p. 1 |
| 90 | “(1) [When supplying combustion air from the indoors] The air supply vent may be clogged. (2) Exhaust vent may be clogged. (3) Abnormal combustion, low gas supply pressure. (4) Condensate drain line may be clogged.” What to check Quoted from the EZ/NRCR Owner's Guide Rev. 10/25, which prints 90, 901 and 902 in this row (p. 31); the 2024 guide prints 90, 901 and 908 (EZ/NRCR Owner's Guide Rev. 01/24, p. 25). Other guides list fewer causes. NRC98, 2017 NRC111, NERC, NRC83 and NRC1111: causes (1) and (3) (NRC98 Owner's Guide Rev. 01/17, p. 28; NRC83/NRC98 Owner's Guide Rev. 03/13, p. 27). NR98 (2020) and NR981: “[NR981-SV] The air inlet filter may be clogged.” and cause (3) (NR98 Owner's Guide Rev. 11/20, p. 26; NR981 Owner's Guide Rev. 03/13, p. 27). NR83, NR71DVC, NR50/NR66/NR71, NR111, 2009 NR98 and 2009 NRC111: only “Abnormal combustion, low gas supply pressure” (NR83 Owner's Guide Rev. 11/20, p. 25; NR50/NR66/NR71 Owner's Guide Rev. 01/11, p. 26; NRC111 Owner's Guide Rev. 09/09, p. 27). On EZTR40, NRC661A/NRC711, NRC661, NR501/NR662 and NER66OD heaters the display shows 901, 902, 903 or 908 and the optional remote shows 90 (EZTR40 Owner's Guide Rev. 01/17, p. 24). EZ technical sheets: “Combustion abnormality (Unit shuts off)”. | EZ, NRCR | Owner checks, then technician | EZ/NRCR guide 10/25 p. 31; EZ/NRCR guide 01/24 p. 25; EZ guide SBB8163-2 p. 18; EZ guide SBB80T9-2 p. 28; NRCR guide 04/21 p. 20 |
| 901 | “Abnormal combustion. The air inlet filter may be clogged.” Quoted from the EZTR40 guide, where 901, 903 and 908 share one row (EZTR40 Owner's Guide Rev. 01/17, p. 24); its technical sheet shows a warning first, “Combustion abnormality (Warning indication)”, then “(Unit shuts off)” (EZTR40 Technical Sheet EXSK072, p. 1). Other models give 901 a different cause. NRC661A/NRC711 and NRC661: “Abnormal combustion. [When supplying combustion air from the indoors] The air supply vent may be clogged.” (NRC661A/NRC711 Owner's Guide Rev. 01/17, p. 25; NRC661 Owner's Guide Rev. 01/13, p. 25). NR501/NR662 and NER66OD: “Abnormal combustion.” (NR501/NR662 Owner's Guide Rev. 01/17, p. 24; NER66OD Owner's Guide Rev. 11/19, p. 24). EZ and NRCR: 901 shares the four-cause 90 row (EZ/NRCR Owner's Guide Rev. 10/25, p. 31; EZ/NRCR Owner's Guide Rev. 01/24, p. 25), and the 2025 EZ sheet writes it 90-1. | EZTR40 | Owner checks, then technician | EZTR40 guide p. 24; EZTR40 tech sheet p. 1 |
| 902 | “Abnormal combustion, low gas supply pressure.” The action is to have a professional check the gas supply pressure and contact the nearest Noritz agent (EZTR40 Owner's Guide Rev. 01/17, p. 24). EZ and NRCR: 902 shares the four-cause 90 row (EZ/NRCR Owner's Guide Rev. 10/25, p. 31), and the 2025 EZ sheet writes it 90-2. | EZTR40, NRC661A/NRC711, NRC661, NR501/NR662/NER66 | Technician | EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25; NR501/NR662 guide p. 24; NER66OD guide p. 24; EZTR40 tech sheet p. 1 |
| 903 | “Abnormal combustion. The air inlet filter may be clogged.” What to check Quoted from the EZTR40 guide (EZTR40 Owner's Guide Rev. 01/17, p. 24); its technical sheet calls it “Combustion abnormality (Unit shuts off)” (EZTR40 Technical Sheet EXSK072, p. 1). The optional remote shows 90. Other models give 903 a different cause. NRC661A/NRC711 and NRC661: “Abnormal combustion. [When supplying combustion air from the indoors] The air supply vent may be clogged.” (NRC661A/NRC711 Owner's Guide Rev. 01/17, p. 25; NRC661 Owner's Guide Rev. 01/13, p. 25). NR501/NR662 and NER66OD: “Abnormal combustion.” (NR501/NR662 Owner's Guide Rev. 01/17, p. 24; NER66OD Owner's Guide Rev. 11/19, p. 24). | EZTR40 | Owner checks, then technician | EZTR40 guide p. 24; EZTR40 tech sheet p. 1 |
| 908 | “Abnormal combustion. The air inlet filter may be clogged.” Quoted from the EZTR40 guide (EZTR40 Owner's Guide Rev. 01/17, p. 24); its technical sheet says the unit is locked and to contact the nearest Noritz agent to reset it (EZTR40 Technical Sheet EXSK072, p. 1). Other models give 908 a different cause. NRC661A/NRC711: “Abnormal combustion. [When supplying combustion air from the indoors] The air supply vent may be clogged.” (NRC661A/NRC711 Owner's Guide Rev. 01/17, p. 25). NR501/NR662 and NER66OD: “Abnormal combustion.” (NR501/NR662 Owner's Guide Rev. 01/17, p. 24; NER66OD Owner's Guide Rev. 11/19, p. 24). The NRC661 guide does not list 908; its technical sheet does (NRC661 Technical Sheet EVRK072, p. 1). EZ and NRCR: 908 shares the four-cause 90 row in the EZ/NRCR Owner's Guide Rev. 01/24 (p. 25); the EZ sheets say a lockout has been activated (EZ Technical Sheet FPFK081, p. 1). | EZTR40 | Owner checks, then technician | EZTR40 guide p. 24; EZTR40 tech sheet p. 1 |
| 91 | “Gas conversion has not been performed correctly.” The 2024 and 2025 EZ/NRCR guides say to contact the installer (EZ/NRCR Owner's Guide Rev. 10/25, p. 31); the 2021 EZ guides do not list 91. A gas conversion kit must be installed by a qualified installer, service agency or the gas supplier (EZ/NRCR Owner's Guide Rev. 10/25, p. 4). The technical sheets use other wording: “May be improper gas type” (EZ Technical Sheet FPFK081, p. 1) and “Improper gas type” on the EZTR40, NRC661A/NRC711 and NRC661, where 91 appears only in the technical sheets (EZTR40 Technical Sheet EXSK072, p. 1). | EZ, NRCR | Technician | EZ/NRCR guide 10/25 p. 31; EZ/NRCR guide 01/24 p. 25 |
| 92 | “The neutralizer needs to be replaced soon.” The guide says the heater can be used for a while with a reduced maximum hot water flow, and to contact the installer or Noritz America Technical Support (NRC111 Owner's Guide Rev. 09/09, p. 27). Field Manual June 2011: “Neutralizer Life Cycle Warning”. | NRC111 (2009) | Technician | NRC111 guide 09/09 p. 27; Field Manual 06/2011 p. 34 |
| 93 | “The neutralizer has reached the end of its service life and must be replaced.” The guide says the heater cannot be used, and to contact the installer or Noritz America Technical Support (NRC111 Owner's Guide Rev. 09/09, p. 27). Field Manual June 2011: “Neutralizer Life Cycle End”. | NRC111 (2009) | Technician | NRC111 guide 09/09 p. 27; Field Manual 06/2011 p. 34 |
| 94 | “Exhaust temperature is too high” Wording of the EZ, EZTR40, NRC661A/NRC711 and NRC661 technical sheets (also shown as 94-1, 94-2 or 941, 942). The EZTR40 Owner's Guide adds “*941 Warning indication. - The unit will continue to operate.”, shows 941 or 942 on the unit and 94 on the optional remote, and says to contact the nearest Noritz agent (EZTR40 Owner's Guide Rev. 01/17, p. 24); EZTR40 Technical Sheet EXSK072 lists 941 as a warning and 942 as “Unit shuts off” (p. 1). Other owner's guides do not list 94. On NRCP heaters Er94 is “Exhaust Overheating (The water heater shuts down when the flue temperature exceed 149°F(65°C))” (NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17, p. 2; NRCP111/NRCP98 Technical Data Sheet Rev. 07/19, p. 2). Field Manual KS-11-0004 calls it “High Exhaust temperature” (p. 26). | EZ, EZTR40, NRC661A/NRC711, NRC661 | Technician | EZTR40 guide p. 24; EZTR40 tech sheet p. 1; EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1 |
| 99 | “Abnormal combustion” The guides say to contact the nearest Noritz agent; NRC111 Owner's Guide Rev. 09/09 says to contact the installer or Noritz America Technical Support (p. 27). On EZ and NRCR heaters only the 2021 guides list 99. EZTR40, NRC661A/NRC711 and NRC661 sheets: “Combustion abnormality (Unit is locked)”, with “To reset this error code, contact the nearest NORITZ agent.” (EZTR40 Technical Sheet EXSK072, p. 1). Field Manuals: “Combustion Abnormality (Unit shuts off)”. | EZ, NRCR, EZTR40, NRC661A/NRC711, NRC661, NRC98/NRC111/NERC, NRC (2013), NRC111 (2009), NR98/NR83/NR71DVC, NR501/NR662/NER66, NR (2009–2013) | Technician | EZ guide SBB8163-2 p. 18; EZ guide SBB80T9-2 p. 28; NRCR guide 04/21 p. 20; EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25; NRC98 guide 01/17 p. 28; NRC83/NRC98 guide 03/13 p. 27; NRC111 guide 09/09 p. 27; NR98 guide 11/20 p. 26; NR501/NR662 guide p. 24; NR50/NR66/NR71 guide p. 26; EZTR40 tech sheet p. 1 |
| 410 | “Multi-System Flow Imbalance Error” Listed only in Noritz technical documents for service technicians; the Field Manual tables do not say which models show it. | Field Manual (models not listed) | Technician | Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 760 | “Remote Controller transmission abnormality” Listed only in Noritz technical documents for service technicians. The 2024 and 2025 EZ sheets say it is kept only in the error code history. On EZTR40, NRC661A/NRC711 and NRC661 heaters the remote shows 760 while the heater's display shows nothing (EZTR40 Technical Sheet EXSK072, p. 1). | EZ, EZTR40, NRC661A/NRC711, NRC661, Field Manual (models not listed) | Technician | EZ tech sheet FPFK081 p. 1; EZ tech sheet FHCK080 p. 1; EZ tech sheet FABK080 p. 1; EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1; Field Manual KS-11-0004 p. 26; Field Manual 06/2011 p. 34 |
| 768 | “Display Window transmission abnormality” Listed only in Noritz technical documents for service technicians. The remote shows 76. | EZTR40, NRC661A/NRC711, NRC661 | Technician | EZTR40 tech sheet p. 1; NRC661A/NRC711 tech sheet p. 1; NRC661 tech sheet p. 1 |
| C1# | “Descaling Reminder (Notice for periodic maintenance)” # is a digit from 1 to 9. The 2021 and 2024 guides call it “Service Reminder”. The reminder is off by default, and the customer or installer turns it on (EZ Installation Manual Rev. 10/25, p. 44). To clear it the heat exchanger must be flushed, a procedure written for a qualified service professional or authorized Noritz service representative (EZ Installation Manual Rev. 10/25, p. 69). | EZ, NRCR | Technician | EZ/NRCR guide 10/25 p. 32; EZ/NRCR guide 01/24 p. 26; EZ guide SBB8163-2 p. 18; EZ guide SBB80T9-2 p. 28; NRCR guide 04/21 p. 20; EZ install manual 10/25 p. 44 |
| C*# | “The unit detects Scale Build-up in the Heat Exchanger. (Warning indication, and then the unit will shut off before long.)” * is 1 to 4 or F; # is 1 to 9 or A, b, C, d, E, F, and the remote shows C1 to C4 (EZTR40 Owner's Guide Rev. 01/17, p. 24). The NRC98, NRC111, NERC, NR98, NR83 and NR71DVC guides give # as 0 to 9. The guides say the heater may shut off and lock, that it can run temporarily if electrical power is disconnected until the heat exchanger can be flushed, and to contact Noritz America about flushing (NRC98 Owner's Guide Rev. 01/17, p. 28). | EZTR40, NRC661A/NRC711, NRC98/NRC111/NERC, NR98/NR83/NR71DVC, NR501/NR662/NER66 | Owner checks, then technician | EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC98 guide 01/17 p. 28; NRC111 guide 01/17 p. 28; NERC98DV guide p. 28; NR98 guide 11/20 p. 26; NR83 guide p. 25; NR71DVC guide p. 25; NR501/NR662 guide p. 24; NER66OD guide p. 24 |
| CF# | “The unit detects the Scale Build-up in the Heat Exchanger many times (The unit is locked.)” The heater is locked after repeated scale codes; the heat exchanger must be flushed, and the guides say to contact Noritz America before flushing (NRC98 Owner's Guide Rev. 01/17, p. 28). | EZTR40, NRC661A/NRC711, NRC98/NRC111/NERC, NR98/NR83/NR71DVC, NR501/NR662/NER66 | Technician | EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC98 guide 01/17 p. 28; NRC111 guide 01/17 p. 28; NERC98DV guide p. 28; NR98 guide 11/20 p. 26; NR83 guide p. 25; NR71DVC guide p. 25; NR501/NR662 guide p. 24; NER66OD guide p. 24 |
| Flashing lamp | “Unit abnormality” NR71-SV and NR71-OD only: a lamp on the heater flashes instead of a number, for any unit abnormality. The guide says to check whether the gas valve is open, then close the hot water fixture and open it again; if the lamp does not start flashing again, the problem is solved (NR50/NR66/NR71 Owner's Guide Rev. 01/11, p. 26). Field Manual June 2011 has a separate flash-count table for NR71 heaters without a remote (p. 35). | NR (2009–2013) | Owner checks, then technician | NR50/NR66/NR71 guide p. 26 |
| Two flashing symbols | “The outlet temperature is colder than set temperature.” Our description of a pictogram: the display shows two flashing symbols and no digits. The guide's action is to contact the nearest Noritz agent (EZTR40 Owner's Guide Rev. 01/17, p. 24). | EZTR40, NRC661A/NRC711, NRC661, NR501/NR662/NER66 | Technician | EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25; NR501/NR662 guide p. 24; NER66OD guide p. 24 |
| Three flashing symbols | “The indication on the display window shown is not an error of unit. If you try to supply a low flow of water when the inlet water temperature is high, hot water is not supplied sometimes (combustion is automatically stopped and the temperature of outlet water does not become hot).” Our description of a pictogram: the display shows three flashing symbols and no digits. Not an error, and the guides give no action (EZTR40 Owner's Guide Rev. 01/17, p. 24). NRC661 Owner's Guide Rev. 01/13 ends the sentence with “the temperature of hot water does not become hot” (p. 25). | EZTR40, NRC661A/NRC711, NRC661, NR501/NR662/NER66 | Owner can check | EZTR40 guide p. 24; NRC661A/NRC711 guide p. 25; NRC661 guide p. 25; NR501/NR662 guide p. 24; NER66OD guide p. 24 |
How to read a Noritz code
A fault code blinks on the heater’s operation panel or display window and on the remote controller, if there is one EZ/NRCR Owner’s Guide Rev. 10/25, p. 31; EZTR40 Owner’s Guide Rev. 01/17, p. 24. NRCP heaters flash “Er” before the number NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39. The EZTR40, NRC661A/NRC711, NRC661, NR501/NR662 and NER66OD show some codes as three digits, such as 903, while their optional remote shows two EZTR40 Owner’s Guide Rev. 01/17, p. 24; NR501/NR662 Owner’s Guide Rev. 01/17, p. 24. In a Quick Connect multi-system with a remote, an F before the number (except F76) marks a code from the secondary unit EZ Technical Sheet FPFK081, p. 1.
One number can mean different things on different models, so read the row for your series. The model is on the rating plate and, on 2025 EZ and NRCR heaters, under “Heater Info.” EZ/NRCR Owner’s Guide Rev. 10/25, p. 32. EZ and NRCR guides come in 2021, 2024 and 2025 editions with different code lists, and none of the Noritz documents we use ties an edition to a serial number.
In the table, EZ also covers the EZTR50 and EZTR75: their product pages link the EZ documents, and the 2025 guide names them only in its warranty table EZ/NRCR Owner’s Guide Rev. 10/25, p. 36. NRC (2013) is the NRC83, NRC98 and NRC1111 models with -DV or -OD in the name. NR (2009–2013) is the NR50, NR66, NR71, NR111, NR981 and the 2009 NR98-SV and NR98-OD.
Clearing a code
The owner’s guides give reset steps for only a few codes, and the code pages here list them. On NRCP heaters a soft lockout clears by itself once the condition goes away, and a hard lockout (Er.11, Er.29, Er.40, plus Er.72 on the NRCP1112 and NRCP982) clears when you press the Power button off and then on NRCP1112/NRCP982 Owner’s Guide Rev. 05/19, p. 39; NRCP111/NRCP98 Owner’s Guide Rev. 05/19, p. 34.
If a code comes back after the listed actions, the EZTR40 guide says to contact Noritz America EZTR40 Owner’s Guide Rev. 01/17, p. 24. Noritz America Technical Support is at 1-866-766-7489 EZ/NRCR Owner’s Guide Rev. 10/25, p. 32. The NERC98DV and NERC11DV guides name Thermalux Customer Care at 855-960-3434 instead NERC98DV Owner’s Guide Rev. 11/19, p. 28; NERC11DV Owner’s Guide Rev. 11/19, p. 28.
When to stop and call a professional
- If the intake or exhaust pipe is displaced, has holes, is clogged or is corroded, do not use the heater EZ/NRCR Owner’s Guide Rev. 10/25, p. 2.
- When a gas leak is noticed, the 2025 guide says to stop use, close the gas valve and, for indoor installations, open windows and doors EZ/NRCR Owner’s Guide Rev. 10/25, p. 3.
- Gas supply pressure is for a professional to check EZ/NRCR Owner’s Guide Rev. 10/25, p. 31. Installation, service and any gas conversion are for a qualified installer, service agency or the gas supplier EZ/NRCR Owner’s Guide Rev. 10/25, p. 4.
- Flushing the heat exchanger, which the scale codes C1#, C*# and CF# call for, is written for a qualified service professional or authorized Noritz service representative EZ Installation Manual Rev. 10/25, p. 69; EZTR40 Installation Manual Rev. 11/20, p. 22.
Rows noted “Listed only in Noritz technical documents for service technicians” come from Noritz technical sheets and field manuals. Owner steps on these pages come only from owner’s guides. The two Field Manuals print one error table for many models and do not say which models show each code, so their codes carry the series “Field Manual (models not listed)” Field Manual KS-11-0004, p. 26; Field Manual June 2011, p. 34. From the NRCR technical sheet, only its NRCR rows 06, 42, 63 and 79 are used here.
Noritz is a trademark of its owner. How House Works is not affiliated with or endorsed by Noritz.
Sources
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- NORITZ America Corporation. EZ/NRCR Owner's Guide Rev. 01/24. SBB81HC, Rev. 01/24; cover title: Condensing Tankless Gas Water Heater Owner's Guide; covers the 2024 EZ111DV, NRCR111DV, EZ98DV, NRCR92DV and EZ71DV (GQ-...-FF US models). Accessed Oct 12, 2026.
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- NORITZ America Corporation. EZ Technical Sheet FHCK080. Sheet code FHCK080, no revision or date printed; 2024 EZ111DV, EZ98DV and EZ71DV (GQ-...-FF US); a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. EZ Technical Sheet FABK080. Sheet code FABK080, no revision or date printed; 2021 EZ111DV (GQ-C3259WX-FF US) and EZ98DV (GQ-C2859WX-FF US); a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. EZ Technical Sheet FDAK080. Sheet code FDAK080, no revision or date printed; 2021 EZ111DV (GQ-C3260WX-FF US) and EZ98DV (GQ-C2860WX-FF US); a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. NRCR Technical Sheet FPHK081. Sheet code FPHK081, no revision or date printed; 2025 NRCR111DV and NRCR92DV (GQ-...-FF-1 US); image-only PDF; only its NRCR rows 06, 42, 63 and 79 are used on this site; a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. EZTR40 Technical Sheet EXSK072. Sheet code EXSK072, no revision or date printed; a service document filed under Field Manual in Noritz's Technical Literature; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. NRC661A/NRC711 Technical Sheet EVPK072. Sheet code EVPK072, no revision or date printed; a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. NRC661 Technical Sheet EVRK072. Sheet code EVRK072, no revision or date printed; a service document; no page numbers printed, p. 1 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. NRCP1112/NRCP982 Technical Data Sheet Rev. 03/17. Rev. 03/17 (printed at the foot of p. 1); a service document filed under Field Manual; no page numbers printed, p. 2 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. NRCP111/NRCP98 Technical Data Sheet Rev. 07/19. Rev. 07/19 (printed at the foot of p. 1); a service document filed under Field Manual; no page numbers printed, p. 2 is the PDF page. Accessed Oct 12, 2026.
- NORITZ America Corporation. Field Manual KS-11-0004. KS-11-0004, Rev. October 2012; cover title: Gas Water Heater Field Manual (NRC83, NRC98, NRC1111/NCC1991, NR981/NC199, NR83-DVC); written for service technician training seminars. Accessed Oct 12, 2026.
- NORITZ America Corporation. Field Manual June 2011. Rev. June 2011; cover title: Gas Water Heater Field Manual (NR50-OD, NR66, NR71, NR98, NCC199, NRC111, NR111, NC380); a service technician training document. Accessed Oct 12, 2026.
- NORITZ America Corporation. EZ Installation Manual Rev. 10/25. SBB81M3-1, Rev. 10/25; cover title: Condensing Tankless Gas Water Heater Installation Manual; covers EZ111DV, EZ98DV and EZ71DV (GQ-...-FF-1 US); linked from the EZTR50 and EZTR75 product pages, which the manual does not name. Accessed Oct 12, 2026.
- NORITZ America Corporation. EZTR40 Installation Manual Rev. 11/20. SBB809L-2, Rev. 11/20; covers NRC663-FSV (EZTR40), indoor installation; p. 22 is an image page without a text layer. Accessed Oct 12, 2026.