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
The same code number can mean something different on another series — make sure you're reading the page for your exact unit:
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: