Noritz tankless water heater code 11
Ignition failure. Code 11 means the same thing on all 5 Noritz series documented here — but the fix, and what it costs, is still worth reading for your exact unit.
What code 11 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| EZ Series & NCC199CDV | Ignition failure | Call a pro | $0–$900 |
| NCC199 & NRC111 | Ignition failure | Call a pro | $0–$900 |
| NR50, NR66 & NR71 | Ignition failure | Call a pro | $0–$900 |
| NR98 & NR111 | Ignition failure | Call a pro | $0–$900 |
| NRC Series | Ignition failure | Call a pro | $0–$900 |
Each row opens the full page for that generation. We hold manuals for EZ Series & NCC199CDV, NCC199 & NRC111, NR50, NR66 & NR71, NR98 & NR111 and NRC Series, and each one gets its own reading of code 11 — what Noritz documents, what you can safely check yourself, and what the repair should cost.
What each manual actually says
The table above compares 5 series in four columns, which is enough to route you and not enough to explain anything. This is the Noritz wording behind each row, one entry per manual, so you can see where the 5 readings of code 11 agree and where they part company.
EZ Series & NCC199CDV — Ignition failure
The burner did not light. Noritz calls it initial flame fault detection. The checklist on this series names a single gas valve rather than the separate solenoid valves of the NRC table: gas supply piping and pressure, igniter spark, the gas valve, the flame rod, and the ground connection at the circuit board — which Noritz flags for special attention because flame detection depends on it.
NCC199 & NRC111 — Ignition failure
The burner never lit — Noritz calls it initial flame fault detection. The checklist is gas supply piping and pressure, igniter spark, the gas solenoid valves, the flame rod, and the ground connection at the circuit board, which Noritz singles out because flame detection depends on a good earth.
NR50, NR66 & NR71 — Ignition failure
The burner never lit — Noritz calls it initial flame fault detection. The checklist is gas supply piping and pressure, igniter spark, the gas solenoid valves, the flame rod, and the ground connection at the circuit board, which Noritz singles out because flame detection depends on a good earth. On an NR71 or N-0631S with no remote controller, this is one of the continuous flashing faults. This is the shortest table on the site — seventeen codes — and that shapes the diagnosis. There is no separate air pressure switch code and no multi-system code to eliminate, so an ignition failure here is gas, spark and earth, with nothing else competing for the explanation.
NR98 & NR111 — Ignition failure
The burner never lit — Noritz calls it initial flame fault detection. The checklist is gas supply piping and pressure, igniter spark, the gas solenoid valves, the flame rod, and the ground connection at the circuit board, which Noritz singles out because flame detection depends on a good earth. On this range the ignition checks are the only ones Noritz gives — there is no neutralizer to rule out here, unlike the NCC199 and NRC111 table, so a code 11 on an NR98 or NR111 is about gas and spark and nothing else.
NRC Series — Ignition failure
The burner never lit. Noritz calls this initial flame fault detection: the unit went through its ignition sequence, looked for a flame at the end of it, and did not find one. The checklist is gas and spark — gas supply piping and pressure, igniter spark, the gas solenoid valves, the flame rod, and the ground connection at the circuit board, which Noritz singles out for special attention because flame detection depends on a good earth.
Does it matter which Noritz you have?
EZ Series & NCC199CDV, NCC199 & NRC111, NR50, NR66 & NR71, NR98 & NR111 and NRC Series all route code 11 the same way: a professional, at $0–$900. That makes it one of the Noritz numbers you can act on before working out which unit you own.
Which Noritz do you have?
On the 5 series that report code 11, the model number on the rating label starts EZ, NCC, GQ, N and NRC — match yours against the 43 listed below. You can also use the full model-number decoder.
Where this comes from
Source: Noritz Service Manual — NRC663 FSV, EZ98DV, EZ111DV, NCC199CDV (Rev. Oct 2017) (p. 32), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 55), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 54), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
Source: Noritz Service Manual — NR50 / NR66 / NR71 / NR98 / NCC199 / NRC111 / NR111 / NC380 (Rev. July 2011) (p. 56), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
Source: Noritz Service Manual — NR501-OD, NR662-OD, NRC661, NRC711 (Rev. Dec 2013) (p. 28), read Sep 2026 — the manufacturer's own documentation for this Noritz range.
The same number on other brands
Code 11 is not a standard across the industry — every manufacturer publishes its own table. If your unit is not a Noritz, this number means something else entirely:
Parts, guides and symptoms behind code 11
Code 11 on these 5 Noritz series points at 3 parts and 3 symptoms, each named by the manufacturer's own procedure for this code.