Noritz tankless water heater code 35
Exhaust thermistor fault. Code 35 means the same thing on all 2 Noritz series documented here — but the fix, and what it costs, is still worth reading for your exact unit.
What code 35 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| EZ Series & NCC199CDV | Exhaust thermistor fault | Call a pro | $150–$500 |
| NRC Series | Exhaust thermistor fault | Call a pro | $150–$500 |
Each row opens the full page for that generation. We hold manuals for EZ Series & NCC199CDV and NRC Series, and each one gets its own reading of code 35 — what Noritz documents, what you can safely check yourself, and what the repair should cost.
What each manual actually says
The table above compares 2 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 2 readings of code 35 agree and where they part company.
EZ Series & NCC199CDV — Exhaust thermistor fault
The sensor in the exhaust is out of range. Noritz measures its resistance, checks for an open or short circuit, and checks the connection — the same procedure as the other thermistors. What makes it different is its position: in the flue, where the appliance watches for an exhaust temperature that says combustion has gone wrong.
NRC Series — Exhaust thermistor fault
The sensor in the exhaust is out of range. Noritz gives it four display-window codes — two pairs for open circuit and short — and the procedure is resistance and connection, the same as the other thermistors. What makes this one different is where it sits: in the exhaust stream, where the appliance watches for a flue temperature that says combustion has gone wrong.
Does it matter which Noritz you have?
EZ Series & NCC199CDV and NRC Series all route code 35 the same way: a professional, at $150–$500. 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 2 series that report code 35, the model number on the rating label starts EZ, NCC, GQ, NRC and NR — match yours against the 13 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 — 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 35 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 35
Code 35 on these 2 Noritz series points at 2 parts and 2 symptoms, each named by the manufacturer's own procedure for this code.