Noritz error code 33
It depends on your series. Code 33 does not point at the same fault on every Noritz unit. Find your series in the table below before you buy a part or book anyone.
What code 33 means on each Noritz series
| Series | What it means | Verdict | Typical cost |
|---|---|---|---|
| EZ Series & NCC199CDV | Heat exchanger outlet thermistor fault | Part replacement | $120–$450 |
| NCC199 & NRC111 | Heat exchanger thermistor fault | Part replacement | $120–$450 |
| NR98 & NR111 | Heat exchanger thermistor fault | Part replacement | $120–$450 |
| NRC Series | Heat exchanger thermistor fault | Part replacement | $120–$450 |
Each series links to the full page: what the manufacturer's manual says for that generation, what you can safely check yourself, and what the repair should cost.
How much the answer changes between series
Every Noritz series that documents code 33 routes it the same way: a replacement part. That is unusual enough to be worth saying, because on this brand the same number often means different work on different generations. Here it does not — so you can act on this page without first establishing which unit you own.
The cost is documented the same way across all 4 series: $120–$450, depending on which of the manufacturer's causes turns out to be yours.
What to check first, whatever your series
These checks are on the manufacturer's list for every Noritz series that reports code 33, so they are safe to work through before you have identified your exact unit. They also cost nothing.
- Book a service call.
If none of those explains it, go to your own series above — the remaining checks differ by generation, and that is the whole reason this page exists.
Which Noritz do you have?
The model number is on the rating label on the unit itself. Match it against the list below — or 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. 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 33 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 33
Everything the 4 Noritz series point at for this code, in one list. A part named here is one the manufacturer's own procedure reaches for.