Noritz NRC Series Code 70
Circuit board fault. The circuit board has reported a fault in itself. Noritz's entire diagnosis column for this code is two words — circuit board failure — and the remark is that power has to be disconnected and reconnected to clear it. The display window appends a digit from 1 to 9 identifying which internal check failed.
Also displayed as: 701, 702, 703, 704, 705, 706, 707, 708, 709
Part replacementThe verdict
Replace a part
Cut the power for a minute and restore it — Noritz's own remark says that is the reset, and a board that faults once on a supply glitch may not fault again. If it comes back, the board is the answer and it is the most expensive single part in the appliance.
Typical cost: $0–$900
US estimate for parts and labor. Prices vary by region and by who does the work — see how we estimate costs.
What the manual says
The meaning above is transcribed from the manufacturer's diagnostic documentation for the NRC Series — not averaged across the brand.
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 exact series.
What you can safely check
- Switch the unit off at the breaker, wait a full minute, and switch it back on.
- Run a hot tap and see whether the code returns.
- Note the third digit shown in the display window before you reset — it tells the technician which check failed.
- If it comes back, book a service call; Noritz gives no other cause for this code.
Code 70 on other Noritz series
Other Noritz series report code 70 under the same fault name, but each manual is transcribed separately and they do not read alike:
Don't confuse this with
One other Noritz NRC Series code points at the circuit board too. They are different components in different places, and ordering a part against the wrong one is the most common way this fault gets expensive: