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Noritz Error Code 11: Ignition failure (no flame detected) (Tankless)

Updated · by Aurora Star Tech Inc.

Noritz error code 11 on a tankless water heater means: Ignition failure (no flame detected). It is also called Noritz diagnostic code 11.

High severityTankless Water HeaterNoritz EZ · Noritz NRCR · Noritz CDV · Noritz NRC/NRCP

Homeowner? What Noritz code 11 means for you

Call a technician Your tankless water heater is reporting: Ignition failure (no flame detected). The tankless water heater has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

  • Check that gas reaches the house: other gas appliances work, or the propane tank is not empty.
  • Make sure the heater is plugged in and its breaker is on. In winter, keep the power on: it protects the unit from freezing.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the hot and cold water valves under the heater are fully open.
  • If you have a remote controller, turn it off and on once. If the code comes back, call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Noritz error code 11 mean?

The burner did not light or the flame rod never saw flame. Noritz points to the three things needed to burn: air, fuel and spark; with the front cover off air is rarely the cause, so start with gas pressure and the ignition/flame rods. Same meaning on premix (EZ/NRCR/CDV) and non-premix (NRC/NRCP) units, but the allowed inlet gas pressures differ by family. On EZ/NRCR, 11 can also show briefly after manual draining (owner's guide) and is not a fault then.

Applies to: All Noritz residential tankless: EZ, NRCR, NCC199CDV (premix) and NRC/NRCP and older (non-premix)

Common causes of Noritz code 11

  • Gas valve closed, empty LP tank or gas cut off at the meter
  • Inlet gas pressure outside the range (undersized gas line, meter too small, water/debris in the gas line, earthquake shutoff valve)
  • Air in a new gas line

A technician checks these and 3 other possible causes on site before replacing any part.

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Noritz models that use code 11

EZ71DVEZ98DVEZ111DVN-0841MCN-0841MC-DVN-0842MCN-0842MC-DVNCC199CDVNRC111-DVNRC111-SVNRCR92DVNRCR111DV

Other Noritz Tankless codes

CodeMeaning
06Low recirculation flow (warning only)
10Abnormal combustion (NRCR, gas supply related)
12Flame loss (repeated)
14Thermal fuse failure
16Abnormally high outlet temperature
20High limit switch tripped
29Condensate collector water level abnormal
061Recirculation abnormality (sub-code of 06)
062Recirculation abnormality (sub-code of 06)
63Recirculation abnormality (no recirculation flow)
65Main water control servo abnormality
66Bypass water control servo abnormality

All Noritz Tankless Water Heater error codes →

Noritz code 11: homeowner questions

What does Noritz code 11 mean?

Ignition failure (no flame detected). The burner did not light or the flame rod never saw flame. Noritz points to the three things needed to burn: air, fuel and spark; with the front cover off air is rarely the cause, so start with gas pressure and the ignition/flame rods.…

Is it safe to keep using my tankless water heater with code 11?

It depends on the cause. The tankless water heater has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset Noritz code 11 myself?

You can try one reset (power off for 30 seconds, then on). If Noritz code 11 comes back, the cause is still there and a licensed technician should check it.

Who can fix Noritz code 11 near me?

Aurora Star Tech Inc. repairs Noritz tankless water heaters in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Tankless Water Heater No Hot Water: What to Check

Troubleshooting guides

Source: Noritz EZ/NRCR/CDV Level 2 Maintenance & Troubleshooting (Premix R2 V2), Common error codes / 11 error code, p.11, 13; Noritz Residential Level 2 Maintenance & Troubleshooting (NRC/NRCP and older, R2 V1), 11 error code, p.6-7; Noritz NRCR Pro training (NRCR92/NRCR111, Printable V3), Gas line conditions, p.19-20; Noritz EZ/NRCR Owner's Guide (Rev. 10-25), Checking for error conditions, p.31. Written in our own words as a summary; always check the original manual.

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.

Emergency HVAC Service

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