TanklessCodes

Noritz error code 73

Circuit board setting fault. Code 73 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.

Typical cost: $100–$800 5 series documented

What code 73 means on each Noritz series

Series What it means Verdict Typical cost
EZ Series & NCC199CDV Circuit board setting fault Call a pro $100–$800
NCC199 & NRC111 Circuit board setting fault Call a pro $100–$800
NR50, NR66 & NR71 Circuit board setting fault Call a pro $100–$800
NR98 & NR111 Circuit board setting fault Call a pro $100–$800
NRC Series Circuit board setting fault Call a pro $100–$800

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 73 routes it the same way: a professional. 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 5 series: $100–$800, 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 73, so they are safe to work through before you have identified your exact unit. They also cost nothing.

  1. Call a licensed professional.

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.

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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.

  • EZ Series & NCC199CDV — EZ98DV (EZTR50), EZ111DV (EZTR75), NCC199CDV, GQ-C2859WX-FF US, GQ-C3259WX-FF US, GQ-C3259WZ-FF US
  • NCC199 & NRC111 — NCC199-SV, NCC199-DV, N-0841MC-DV, NRC111-SV, NRC111-DV, N-0842MC-DV
  • NR50, NR66 & NR71 — NR50-OD, NR66-SV, NR66-OD, N-0531S-OD, NR71-SV, NR71-OD, N-0631S-OD
  • NR98 & NR111 — NR98-SV, NR98-OD, NR98-DVC, NC199-OD, NC199-DVC, N-0751M-OD, N-0751M-DV, N-0751M-DVC, NR111-SV, NR111-OD, NR111-DV, NC250-SV-ASME, NC250-DV-ASME, N-0931M-OD, N-0931M-DV, NC380-SV-ASME, N-1321M-ASME
  • NRC Series — NRC661-DV, NRC661-OD, NRC711-DV, NRC711-OD, NRC663-FSV (EZTR40), NR501-OD, NR662-OD

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 73 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 73

Everything the 5 Noritz series point at for this code, in one list. A part named here is one the manufacturer's own procedure reaches for.

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